This French / English glossary of medical and molecular genetics is
intended for students in human and biological sciences as well as
medical and para-medical personnel. It is mainly a tool for teaching and
This glossary contains terminology frequently used in clinics and the
laboratory. Within all areas of genetics the utilisation of terms in the
glossary may also evolve with time or develop specific conations in
different areas of study.
There is no direct correspondence between the French and English terms
defined in these glossaries. Certain terms exist in only one of these
languages. Also the utilisation of a given term may differ to some
extent between French and English. The definitions of terms common to
both glossaries are not necessarily literal translations of one another.
Suggestions, corrections as well as the addition of new terms are
We are grateful to the authors of those references who have contributed
to the preparation of this glossary.
Acardia (French : acardia) Congenital absence of the
Acellular system, see:
Acentric (French : acentrique) Absence of centromere in
a chromosome structure.
Achondrogenesis (French : achondrogénèse)
Example of bone dysplasia due to a mutation in a collagen gene, COL2A1.
Skeletal malformations are seen at ultrasound during the second
trimester of pregnancy.
Acrocentric (French : acrocentrique) Position of the
centromere near the end of a chromosome. Chromosomes 13-15 and 21,22 in
man are acrocentric.
Adaptor (French : adapteur) Short nucleotidic sequence
that has the property to link two DNA fragments that hat have no
terminal complementary sequences.
Adenine (French : adénine) A nitrogenous base,
one member of the base pair A-T, adenine- thymine.
ADN transfer, Southern blotting (French : French :
marquage Southern) Transfer by absorption of DNA fragments separated in
electrophoretic gels to membrane filters for detection of specific base
sequences by radio-labelled complementary probes.
Advanced maternal age, AMA
(French : âge maternel avancé, AMA) In most prenatal
diagnostic clinics 35 years of age and more is considered as advanced
maternal age due to the increased risk of chromosomal non disjunction in
Affinity chromatography (French : chromatographie
daffinité) Any form of chromatography in which the components of
the sample are separated on the basis of chemical affinity for a
substance such as a binding protein or an immunoglobulin.
AFP, alpha foetoprotein (French :
AFP, alphafoetoprotéine) Specific foetoglobulin synthesized by
the liver and secreted in foetal serum during the foetal life and the
neonatal period. An open spinal defect in the fetus is usually
accompaniedby an increase in AFP in the amniotic fluid and a
transudation towards the maternal circulation. AFP measurements in
amniotic fluid and maternal serum are used in prenatal diagnosis of
Agenesis (French : agénésie) Absence of
an organ or structure.
(French : allèle) Alternative forms of a genetic locus; a single
allele for each locus is inherited separately from each parent. Example
: at a locus for eye colour the allele might result in blue or brown
Allelic frequencies (French : fréquences
alléliques) Frequencies of allelic genes.
Allelomorph gene, see: alleles.
Allotransplant (French : allotransplant) Organ or
tissue transplant between two individuals.
Alpha foetoprotein, see AFP.
Alu sequences (French : séquences ALU) DNA
segments of approximately 300 base pairs with similar sequences. There
are 50,000 copies in the human genome. They have a reconnaissance site
for the ALU restriction enzyme.
AMA, see advanced maternal age.
(French : acide
aminé) Any of a class of 20 molecules that are combined to form
proteins in living things. The sequence of amino acids in a protein and
hence protein function are determined by the genetic code.
(French : amniocentèse) Transabdominal or transuterine aspiration
of amniotic fluid usually performed during the second trimester of
pregnancy, for instance in the process of prenatal diagnosis of a
Amplifiable plasmid (French : plasmide amplifiable)
Plasmid that continues to replicate even when host cell multiplication
Amplification (French : amplification) An increase in
the number of copies of a specific DNA fragment; can take place in vivo
or in vitro. See cloning,
polymerase chain reaction.
Amplification, DNA (French : amplification dADN) In
vivo or in vitro increase in the number of a specific DNA fragments.
(French : amplification de gène) The increase in number of those
genes needed for specialized functions in certain differentiated cells.
Analogue base (French : base analogue) Molecule which
can replace a structure similar to nitrogenous DNA or RNA bases. Example
: 5-bromo-uracil is a mutagenic analogue.
Anaphase (French : anaphase) Stage in and the first and second following the metaphase, during which the centromere splits and
the chromatids which were lined up on the spindle begin to move apart
towards opposite poles of the spindle.
Anencephaly (French : anencéphalie) Absence of
cranial bone structure usually accompanied by a severe brain defect.
Aneuploidy (French : aneuploïdie) Situation when
one or more chromosomes, missing or in excess of the normal modal
number, is considered a deviation from the 2n ratio.
(French : Angelman, syndrome de) Angelman and Prader Willi syndromes are
examples of syndromes related to parental imprinting. Both syndromes
include mental retardation and clinical anomalies. They are due to the
loss of a segment of chromosome 15 located in the proximal region of the
long arm, 15q11q13. Depending on the parental origin of chromosome 15
and the exact location of the chromosomal anomaly, two different
syndromes are identified.
Annealing (French : annelage) Hybridization of a
synthetic oligonucleotide to a single strand nucleic acid. It is how a
specific nucleotide sequence can be identified.
Anophtalmia (French : anophtalmie) Congenital absence
Anthelix (French : anthélix) Proximal fold of
the external ear.
Antibody (French : anticorps) A specific substance
produced by man, and animal, as a reaction to the presence of an
(French : anticipation) Phenomenon in which the severity of the
condition seems to increase or occur at an earlier age in subsequent
(French : anticodon)
Group of three nucleotides located at one end of the transfer tRNA and
by which it adapts, to the corresponding codon of the messenger mRNA, to
fix the amino acid it carries.
Antigen (French : antigène) A substance which
has the power of inducing, in man or in an animal, the formation of
(French : brin
anti-sens) Nucleic acid that has a sequence exactly opposite to a mRNA
molecule made by the body; it binds to the mRNA molecule to prevent a
protein from being made.
Apoptosis (French : apoptose) Programmed cell death.
Arachnodactyly (French : arachnodactylie) Long and thin
Arhinencephaly (French : arhinencéphalie)
Absence of mid-brain structure.Arrayed library (French : banque de gènes)
Individual primary recombinant clones (hosted in phage, cosmid, YAC, or
other vector) that are placed in two-dimensional arrays inmicrotiter
dishes. Each primary clone can be identified by the identity of the
plate and the clone location (row and column) on that plate. Arrayed
libraries of clones can be used for many applications, including
screening for a specific gene or genomic region of interest as well as
for physical mapping. Information gathered on individual clones from
various genetic linkage and physical map analyses is entered into a
relational database and used to construct physical and genetic linkage
maps simultaneously; clone identifiers serve to interrelate the
Artificial gene (French : gène artificiel) A
double-stranded DNA molecule, carrying a specific sequence, that will
code for a specific amino acid sequence and that has been produced in
Ascites (French : ascite) Accumulation of fluid in the
Asymmetrical division (French : division
asymétrique) Unequal segregation of chromosomes in mitosis. It
leads to two daughter cells that have a different and abnormal number of
chromosomes. Example: 46,XX leading to 47,XXX / 45,X.
A-T, see base pair.
AT, see ataxia telangiectasia.
Ataxia telangiectasia, AT
(French : Ataxie télangiectasique, AT) Ataxia telangiectasia is
an autosomal recessive disease characterized by a neurological and
immunological symptomatology. Lymphoma and leukemia are often observed
as complications of this syndrome. Cellular clones are identified that
have chromosomal anomalies involving chromosomes 7 and 14. There is
deficiency in repair of lesions induced by ionizing radiations.
Attenuator (French : atténuateur) A sequence of
bases that occurs in the leader sequence of some operons and controls
transcription. Synthesis of RNA may be terminated at this site.
Autogen regulation (French : régulation
autogène) Regulation system where a gene product controls its own
Autogenic recombination (French : rebombinaison
autogène) Regulation system where a gene product controls its own
Autolog graft (French : autogreffe) Cell or tissue
graft derived from it own body.
Autoradiography (French : autoradiographie) A technique
that uses X- ray film to visualize radioactively labelled molecules or
fragments of molecules; used in analyzing length and number of DNA
fragments after they are separated by gel electrophoresis.
Autosome (French : autosome) A chromosome not involved
in sex determination. The diploid human genome consists of 46
chromosomes, 22 pairs of autosomes, and 1 pair of sex chromosomes : the
X and Y chromosomes.
Auxotrophic (French : auxotrophie) Requiring a growth
factor that is not required by the parental or prototype strain; may
refer to microorganisms.
BAC, bacterial artificial chromosome (French :
chromosome bactérien artificiel, BAC) A vector used to clone DNA
fragments of 100 to 300 kb insert size, average of 150 kb in Escherichia
coli cells. Based on the naturally occurring F-factor plasmid found in
the bacterium Escherichia coli.
Back mutation (French : réversion vraie).
Bacteriophage (French : bactériophage), see
Balanced translocation (French : translocation
équilibrée) transposisiton of chromosomal segments without
modification of the quantity of genetic material.Banding, see
Barr body (French : corpuscule de Barr), see
Base pair (French : paire de
bases) Two nitrogenous bases, adenine and thymine or guanine and
cytosine, held together by weak bonds. Two strands of DNA are held
together in the shape of a double helix by the bonds between base pairs.
Base pairing (French : appariement de bases) The
pairing of nitrogenous bases in the polynucleotide chains by nitrogen
bonds in a specific manner. The pairing occurs between a purine base of
one strain and a pyrimidine of another strain in DNA, RNA or hybrid
DNA/RNA molecules. In DNA the complementary bases pairs are Adenine and
Thymine and Guanine and Cytosine. In RNA the base pairs are Adenine with
Uracil and Guanine with Cytosine.
Base pair substitution (French : substitution dune
paire de bases) A class of lesions in DNA molecules which can give rise
to gene mutations. They consist of transitions which preserve the
purine-pyrimidine axis, and of transversions which reverse it.
Base ratio AT / GC (French : rapport de bases AT / GC)
The amount of A equals the amount of T and the amount of G equals the
amount of C but he amount of A+T does not equals the amount of G + C.
This ratio is constant within a species but varies between species.
Base sequence (French :
séquence de bases) The order of nucleotide bases in a DNA
Base sequence analysis
(French : analyse dune séquence de bases) A method, sometimes
automated, for determining the base sequence.
Base triplets, triplet code, codon (French : triplets
de bases) A sequence of 3 nucleotides comprising a codon of a nucleic
acid and representing the code for an amino acid.
Bayesian analysis (French : analyse bayésienne)
Mathematical method for calculating probality of the carrier state in
mendelian disorders combining several independent likelihoods.
Beckwith Wiedeman, syndrome
(French : syndrome de Beckwith Wiedeman) Malformation syndrome
characterized by a macroglossia, omphalocele and macrosomia. This is an
example of a syndrome due to the phenomenon of parental imprinting. The
gene is localized at 11p15.5.
Biotechnology (French : biotechnologie) A set of
biological techniques developed through basic research and now applied
to research and product development. In particular, the use by industry
of recombinant DNA, cell fusion, and new bioprocessing techniques.
(French : bivalent) A
part of homologous chromosomes in association as seen at metaphase of
the first meiotic division.
bp, see base pair.
Brachydactyly (French : brachydactylie) Short finger.
Brachyphalangy (French : brachyphalangie) Short
The first breast cancer genes to be identified. Mutated forms of these
genes are believed to be responsible for about half the cases of
inherited breast cancer, especially those that occur in younger women.
Both are tumour suppressor genes.
Breakage syndrome (French : maladie cassante, syndrome
dinstabilité chromosomique) Syndrome manifested by chromosomal
anomalies, mainly chromosomal breakage and chromatid exchange.
Brushfield spots (French : taches de Brushfield)
Presence of white speckles on the iris, a phenomenon commonly seen in
(French : CAAT,
séquence) Sequence that has been conserved in some eukaryotic
promoters. It lies about 40 base pairs upstream from the TATA box. This
region controls the frequency of initiation by RNA polymerase.
Candidate gene (French : gène candidat) Gene
suspected to be involved in the etiology of a disease.
Canthus (French : canthus) Inner
and outer corners of the eyes.
CAP, catabolite activator protein (French :
protéine CAP) The CAP is a positive regulatory protein, activated
by cyclic AMP needed for RNA polymerase to initiate transcription of
certain operons of E. coli. The CAP protein can bind at different sites
relative to RNA polymerase.
Caruncle, see: canthus.
CAT assay (French : CAT, essai) Reporter gene assay
used to measure activity of a promoter under different conditions, such
as to define elements of a promoter or to study signals that activates
an intact promoter.
Cell colony (French : colonie cellulaire) Group of
cells derived from the same initial cell.
Cell free system (French : système acellulaire)
a preparation obtained from a broken cell preparation by differential
centrifugation. A system composed of subcellular fractions and cell-free
extracts, but devoid of intact cells.
Cell line (French : lignée cellulaire) A
cultured cell type that can be reproduced indefinitely, or is
Cell sorter (French : trieur de cellules) Apparatus
that allows to sort different cell types or particles.
Cell strain (French : souche cellulaire) A population
of animal cells that develops from a primary culture by reseeding
serially; the characteristics of the parent cell are retained in
(French : cycle
cellulaire) One can distinguish 4 successive phases in a somatic cell
life : mitosis, G1 phase, S phase of DNA replication and phase G2.
Phases G1, S and G2 are found in interphase.
Centimorgan, cM (French : cM
centimorgan) A unit of measure of recombination frequency. One
centimorgan is equal to a 1% chance that a marker at one genetic locus
will be separated from a marker at a second locus due to crossing over
in a single generation. In human beings, 1 centimorgan is equivalent, on
average, to 1 million base pairs.
Centric fusion (French : fusion centrique) Fusion of
chromosomes at the level of the centromere.
(French : centromère) A specialized chromosome region to which
spindle fibres attach during cell division.
Cephalometry (French : céphalométrie)
Measurement of the head.
Chiasma (French : chiasma) Exchange sites between
chromatids observed in prophase of meiosis 1 subsequent to crossing
Chimera (French : chimera) An organism that contains
cells or tissues with a different phenotype. These can be mutated cells
of the host organism or cells from a different organism or species.
Chimeric gene, hybrid gene (French : gène
chimérique) Gene made of DNA fragments of different origins.
Chorionic villus sampling, chorionic
(French : villosités choriales, prélèvement de) A
procedure used for prenatal diagnosis at the end of the first trimester
around the 12th to the 14th week of pregnancy. Fetal tissue is withdrawn
from the villus area of the chorion either trans uterine cervix or trans
abdominal under ultrasonic guidance.
Chromatid (French : chromatide) A duplicated chromosome
is formed by two longitudinal units or chromatids joined at the
centromeric region. A chromosome is formed by two sister chromatids .
Each chromatid is made of a long DNA strand unique and identical to the
sister chromatid but different from the homologue chromosome originating
from the other parent.
Chromatid exchange, see:
(French : chromatine) Constitutive structure of chromosomes made of DNA,
basic chromosomal proteins and small RNA quantities. Chromatin is
visible during interphase.
Chromonema (French : chromonéma,
chromonème) The thin, threadlike form of an uncoiled chromosome
seen in interphase, early prophase, and late telophase, as opposed to
the tightly coiled metaphase chromosome.
(French : anomalie chromosomique) A chromosome anomaly can be
constitutional, acquired, homogenous, mosaic, numerical, structural.
Chromosomal condensation (French : condensation
chromosomique) Induction of chromosomal condensation in an interphase
nucleus by fusion with a cell in mitosis. Condense chromosomes in S
phase appear pulverized.
(French : chromosome)
The self- replicating genetic structures of cells containing the
cellular DNA that bears in its nucleotide sequence the linear array of
genes. In prokaryotes, chromosomal DNA is circular, and the entire
genome is carried on one chromosome. Eukaryotic genomes consist of a
number of chromosomes whose DNA is associated with different kinds of
(French : bande chromosomique) Chromosome regions identified by specific
Chromosome instability syndrome
(French : syndrome dinstabilité chromosomique) Genetic disease
characterized by an increase rate of chromosomal breaks, exchange
between sister chromatids and spontaneous structural anomalies.
Chromosome jumping (French : saut chromosomique)
Methods for obtaining at a considerable distance from an initial cloned
fragment without the need for overlapping clones of DNA regions between
the two sites.
Chromosome puff (French :
puff chromosomique) An enlarged region along a polytene chromosome, the
site of active transcription.
Chromosome set (French : haplome) See
Chromosome walking (French : marche le long dun
chromosome) Sequential isolation of molecular clones in order to span
large intervals on the chromosome.
Cis control (French : contrôle en cis).
Cis-trans position effect (French : effet de position
cis-trans) Terms cis and trans describe the gene position on homologue
chromosomes in double heterozygote individuals. When two alleles are
located near each other on the same chromosome,they are in cis position.
When they are located on different homologue chromosomes they are in
trans position. Cis and trans are analogue to coupling and repulsion.
Cistron (French : cistron) Genetic function unit
defined by the cis-trans test. The smallest unit of genetic material
that must be intact to function as a transmitter of genetic information.
Cleavage site (French : site de coupure)The cleavages
generated by restriction endonucleases can be within or immediately
adjacent to the recognition sequence but in some cases the cleavages are
displaced from the recognition sequence by a specific number of
Cleft palate (French : fente palatine) Fissure of the
mucous membrane and / or the bone structure of the palate.
Clinical heterogeneity (French :
hétérogénéité clinique) Different
phenotypes due to mutations in the same gene.
Clinodactyly (French : clinodactylie) Incurved finger.
Clone (French : clone) A group of cells derived from a
Clone bank (French : banque de clones) See
Clone sorting (French : criblage) Operation of
identification and sorting of clones.
Cloning (French : clonage) The
process of asexually producing a group of cells (clones), all
genetically identical, from a single ancestor. In recombinant DNA
technology, the use of DNA manipulation procedures to produce multiple
copies of a single gene or segment of DNA is referred to as cloning DNA.
Cloning vector (French :
vecteur de clonage) DNA molecule originating from a virus, a plasmid, or
the cell of a higher organism into which another DNA fragment of
appropriate size can be integrated without loss of the vectors capacity
for self-replication; vectors introduce foreign DNA into host cells,
where it can be reproduced in large quantities. Examples are plasmids,
cosmids, and yeast artificial chromosomes; vectors are often recombinant
molecules containing DNA sequences from several sources.
Club foot (French : pied bot) Congenital deformation of
cM, see centimorgan.
Coarctation of aorta (French : coarctation de laorte)
Congenital cardiac anomaly manifested by a constriction of the aorta
Code, see : genetic code.
Coding sequence, see:
Codominant (French : codominant) Two alleles that are
expressed simultaneously in the heterozygote state. Example the ABO
Codon, see: genetic code.
Coefficient of inbreeding, see:
Coloboma (French : colobome) Congenital defect seen as
a fissure. Examples : coloboma of the eyelid, iris, retina
Compatibility (French : compatibilité) Tissular
compatibility or histocompatibility allows successful grafts;
histocompatibility of the donor and recipient are identical or very
Complementary DNA, cDNA
(French : ADN complémentaire, ADNc) DNA that is synthesized from
a messenger RNA template; the single-stranded form is often used as a
probe in physical mapping.
Complementary sequences (French : séquences
complémentaires) Nucleic acid base sequences that can form a
double- stranded structure by matching base pairs; the complementary
sequence to G- T- A- C is C- A- T- G.
Complementation (French :
complementation) Complementary effect of a double mutation on different
genes. The two mutant genes may reconstitute a normal phenotype.
Xeroderma pigmentosum is an example of complementation.
Compound heterozygote, see heterozygote composite.
Conditional mutation (French : mutation conditionnelle)
Mutation expressed only under certain conditions. Lethal mutations exist
in a cell but in the homozygote state under conditional forms, like for
instance if they are expressed at certain temperatures.
(French : mosaïque placentaire) Chromosomal mosaicism limited to
Congenital (French : congénital) Presence at
birth of a trait or defect.
Conjugation, mating (French : conjugaison) Natural
transfer of plasmidic or chromosomal DNA from a bacterial cell to
another via a cytoplasmic bridge.
(French : coefficient de consanguinité) Probality for an
individual to carry two copies of the same gene transmitted by his
parents who have a common ancestor.
(French : séquence conservée) A base sequence in a DNA
molecule (or an amino acid sequence in a protein) that has remained
essentially unchanged throughout evolution.
Constitutive gene (French : gene constitutive) Gene
expressed without particular regulation.
Constitutive mutation (French : mutation constitutive)
Mutation that inhibits the normal gene regulation; its expression
becomes independent of environmental factors.
Constriction (French : constriction) Reduced thickness
in a chromosomal region. The centromere is the primary constriction.
Chromosome 1,9,16 have a secondary constriction.
Contact inhibition (French : inhibition de contact) The
inhibition of cell division and cell motility in normal animal cells
when in close contact with each other.
Contig map (French : carte de contig) A map depicting
the relative order of a linked library of small overlapping clones
representing a complete chromosomal segment.
Contigs (French : contigs) Group of clones representing
overlapping regions of a genome used to determine the physical map of a
chromosome region. Contig is the abbreviation for contiguous.
Copy error (French : erreur de copie) an error that
arises during DNA replication from a failure to insert nucleotides
complementary to those in the parent DNA chain.
Corepressor (French : corépresseur) Affector
molecule that modifies a regulatory protein (activation), allowing it to
bind to an operator to inactivate transcription.
Cosmid (French : cosmide)
Artificially constructed cloning vector containing the cos gene of phage
lambda. Cosmids can be packaged in lambda phage particles for infection
into E. coli; this permits cloning of larger DNA fragments (up to 45 kb)
than can be introduced into bacterial hosts in plasmid vectors.
Coupling (French : couplage) The occurrence on the same
chromosome in a double heterozygote of the two mutant genes of interest,
the normal alleles being on the homologous chromosome. The genes are
said to be linked in coupling.
Craniolacuna (French : craniolacunie) Circumscribed
deficient cranial bone defect.
Craniosynostosis (French : craniosynostose) Fusion of
Crossing over (French :
enjambement) The breaking during meiosis of one maternal and one
paternal chromosomes, the exchange of corresponding sections of DNA, and
the rejoining of the chromosomes. This process can result in an exchange
of alleles between chromosomes.
Cybrid (French : cybride) Cytoplasmic hybrid resulting
from the fusion of protoplasts. A hybrid contains the cytoplasmic and
nuclear genetic information from the two parental cells.
Cycline (French : cycline) Protein family that plays an
important role in the regulation of cell division.
Cyst (French : kyste) Abnormal closed cavity, of
various sizes in which there is a liquid collection of infectious or
Cystic fibrosis, mucoviscidosis
(French : fibrose kystique, mucoviscidose) A disease affecting the
pancreas, gastro intestinal and pulmonary functions and due to several
different mutations in the CFTR gene located on chromosome 7 at the
Cytoplasmic gene (French : gène
extrachromosomique) Any gene that ordinarily exists on nucleic acid in
the cytoplasm, especially on mitochondrial or chloroplast chromosomes.
(French : hérédité cytoplasmique, maternelle,
extranucléaire) The inheritance of traits controlled by genes
located on the DNA of mitochondria.
Cytosine-C (French : cytosine-C) A nitrogenous base,
one member of the base pair G- C (guanine and cytosine).
Dalton atomic mass unit (French : Dalton, unité
de masse) Atomic mass unit. One Dalton corresponds to one hydrogen atom
(1,657 x 10 -24).
DAPI (French : DAPI) Chromosome stain derived from
fluorescent stain < 4,6-diamidino-2-phenylindole> that stains
preferentially heterochromatin of chromosomes 9,15 and Y.
Defective prophage, see
Deformation (French : déformation) Malformation
due to an abnormal position of a limb or an abnormal pressure.
Dehiscence (French : déhiscence) The formation
of a fissure.
: délétion) Loss of part of a whole chromosome or loss of
DNA nucleotide bases.
Denaturation (French : dénaturation) Formation
of a single DNA strand from a double strain under heating of chemical
bonds responsible for base pairing.
Denaturation mapping (French : cartographie par
dénaturation partielle) A method employing electron microscopy of
DNA partially denaturated which permits the decision as to whether the
gene sequence in a viral genome is linear or circularly permuted.
De novo mutation (French : mutation de novo,
néo-mutation) Spontaneously occurring mutation.
Derepression (French : dérépression) An
increase in the synthesis of the product of a regulated gene by
interference with the action of a repressor. It can be produced by the
mutation of the repressor gene or of the operator gene or by an inducer
that binds to the repressor, releasing it from the operator.
Dermatoglyphics (French : dermatoglyphes) The study of
the surface markings of the skin. Dermatoglyphic studies are used in a
number of malformation syndromes due to a chromosomal aberration as in
trisomy 21 or Down syndrome.
diacinèse) Terminal phase of the first meiotic division during
which the chromosomes are tightly bond and strongly coloured by the
(French : dicentrique) An aberrant chromosome that contains two
Differentiation (French : différenciation) The
act or process of acquiring completely individual characters, such as
occurs in the progressive diversification of cells and tissues of the
DiGeorge, Velo Cardio Facial, CATCH 22, syndrome
(French : DiGeorge, VeloCardio Facial, CATCH 22, syndrome) Syndrome due
to a deletion at the 22q11.2 locus, involving several genes accompanied
by, in VCF, facial dysmorphism, palatal insufficiency, heart defect or,
in Di George syndrome, parathyroid hypoplasia, thymus hypoplasia, and
outflow of the heart defect.
Diploid (French : diploïde) A full set of genetic
material, consisting of paired chromosomes one chromosome from each
parental set. Most animal cells except the gametes have a diploid set of
chromosomes. The diploid human genome has 46 chromosomes.
diplotène) One prophase stage of the first meiotic division.
Discordant (French : discordant) A twin pair (or set of
individuals) in which one member exhibits a certain trait and the other
Disomy uniparental, UPD, see
Dispermia (French : diandrie) Presence of two
spermatozoid during the fertilization likely to lead to a triploidy.
Disruption (French : disruption) In the disruption
sequence the fetus is subject to a destructive problem. It may be a
vascular, infectious or mechanical problem leading to a malformation.
One example is the effect of an amniotic band.
Dizygote (French : dizygotie) The product of
fertilization of two separate eggs by two separate sperms; non identical
(French : ADN, acide désoyribonucléique) The molecule that
encodes genetic information. DNA is a double- base pairs of nucleotides.
the four nucleotides in DNA contain the bases stranded molecule held
together by weak bonds between base pairs of nucleotides. The four
nucleotides in DNA contain the bases: adenine (A), guanine (G), cytosine
(C), and thymine (T). In nature, base pairs form only between A and T
and between G and C; thus the base sequence of each single strand can be
deduced from that of its partner.
DNA probes, see: probe.
réparation de lADN) Genes encoding proteins that correct errors
in DNA sequencing.
replication dADN) The use of existing DNA as a template for the
synthesis of new DNA strands. In humans and other eukaryotes,
replication occurs in the cell nucleus.
DNA-RNA hybrid (French : hybride ADN-ARN) A double
helix consisting of one chain of DNA hydrogen bonded to a complementary
chain of RNA.
DNA sequence (French : séquence dADN) The
relative order of base pairs, whether in a fragment of DNA, a gene, a
chromosome, or an entire genome. See:
base sequence analysis.
DNA synthetizer (French : synthétiseur dADN) An
automated machine design to synthesize short polynucleotide chains
-oligonucleotides- similar in structure to DNA.
DNA transfer, see:
Domain (French : domaine) Discrete portion of a protein
with its own function. The combination of domains in a single protein
determines its overall function.
Dominant (French : dominant) An allele that is almost
always expressed, even if only one copy is present.
Double helix (French : double hélice) The shape
that two linear strands of DNA assume when bonded together.
Double heterozygote, see:
composite, compound heterozygote.
Double minute chromosomes
(French : chromosome minuscule double) Fragment of unstable
extrachromosomic DNA without a centromere. Minute chromosomes are small
spherical structures, observed in pairs in varying number from cell to
cell. They stain homogeneously. They are duplicated once in mitosis and
are lost in cellular division.Ductus arteriosus, patent (French : persistance du
canal artériel) Persistence of the arterial canal after birth.
Duplicate (French : dupliquer) Make a copy.
Dysgenic (French : dysgénique) Detrimental to
the hereditary qualities of man or tending to counteract racial
improvement through an influence bearing on reproduction. Refers to a
Dysmorphism (French : dysmorphisme) Developmental
anomaliy seen in a variety of syndromes with a genetic or environmental
Dysostosis (French : dysostose) Defective ossification.
Dysplasia (French : dysplasia) Abnormality of
Dysraphia (French : dysraphie) Developmental defect of
the median raphe. Examples: spina bifida, cleft lip.
Dysraphism (French : dysraphisme) Term used to describe
a neural tube or spine anomaly.
E. coli (French : E coli) Escherichia colli is a common
bacterium that has been studied intensively by geneticists because of
its small genome size, normal lack of pathogenicity, and ease of growth
in the laboratory.
Ectoderm (French : ectoderme) The outer of three layers
of cells comprising the early embryo. Gives rise to skin and neural
Effusion (French : épanchement) Abnormal
presence of fluid in a tissue or cavity.
Electrofocusing, electro focalisation, see
Electrophoresis (French : électrophorèse)
A method of separating large molecules (such as DNA fragments or
proteins) from a mixture of similar molecules. An electric current is
passed through a medium containing the mixture, and each kind of
molecule travels through the medium at a different rate, depending on
its electrical charge and size. Separation is based on these
differences. Agarose and acrylamide gels are the media commonly used for
electrophoresis of proteins and nucleic acids.
Electroporation (French : électroporation)
Technique used to facilitate the penetration of DNA in cells based on
the use of electric pulsions to increase the membrane permeability.
Embryo (French : embryon) fetus before the end of the
Embryonic biopsy (French : biopsie embryonnaire) Biopsy
of embryonic tissues usually performed on spontaneous miscarriage
Embryonic stem cell, see:
Encephalocele (French : encéphalocèle)
Cranial defect of the midline with hernia of the meningeal membrane
containing spinal fluid and abnormal brain tissue.
3 End, terminus
(French : extrémité 3) The end of a polynucleotide chain
terminating with a 3 carbon atom. The 5 position of one pentose ring
is connected to the 3 position of the next pentose ring via a phosphate
group. All RNA chains, as well as DNA chains, grow in the 5 to 3
5 End, terminus
(French : extrémité 5) The beginning of a polynucleotide
chain terminating which has a free 5 group. The 5 position of one
pentose ring is connected to the 3 position of the next pentose ring
via a phosphate group. All RNA chains, as well as DNA chains, grow in
the 5 to 3 direction.
Endoderm (French : endoderme) One of three layers of
cells comprising the early embryo It gives rise to the lining of the gut
and cells of the pancreas and liver.
Endonuclease (French : endonucléase) An enzyme
that cleaves its nucleic acid substrate at internal sites in the
Endoreduplication (French : endoreduplication) Presence
of duplicated chromosomes in metaphase with four chromatids and two
centromeres.This duplication is total if all chromosomes are concerned
and selective if only one chromosome or part of it is duplicated.
amplificateur) Element that increases the utilization of (some)
eucaryotic promoters in cis configuration, but that can function in any
1ocation, upstream or downstream, relative to the promoter.
Enzyme (French : enzyme) A protein that acts as a
catalyst, speeding the rate at which a biochemical reaction proceeds but
not altering the direction or nature of the reaction.
Epicanthus (French : épicanthus) A fold of skin
projected over the inner canthus.
Epidemiology (French : épidémiologie)
Study of the different factors that intervene in the onset and evolution
Epigenetic (French : épigénétique)
The term that refers to any factor that can affect the phenotype without
change in the genotype.
Equatorial plane (French : plan équatorial)
Alignment of chromosomes at metaphase in a ring formation at the nuclear
EST, Expressed sequence tag, see
sequence tagged site.
(French : euchromatine) Region of chromosomes that have a normal cycle
of spiralisation-despiralisation by opposition to heterochromatin.
Eukaryote (French : eucaryote) Cell or organism with
membrane-bound, structurally discrete nucleus and other well- developed
subcellular compartments. Eukaryotes include all organisms except
viruses, bacteria, and blue- green algae.
Euploidy (French : euploïdie) Normal number of
Evolutionarily conserved, see :
Exogenous DNA (French : ADN exogène) DNA
originating outside an organism.
Exons (French : exon) The protein-coding DNA sequences
of a gene.
Exonuclease (French : exonucléase) An enzyme
that cleaves nucleotides sequentially from free ends of a linear nucleic
Expressed gene, see
Expressivity (French : expressivité) Intensity
of gene expression from mild to severe.
Extremity 3, see:
3 end terminus.
Extremity 5, see: 5 end terminus.
Fallot tetralogy (French : tétralogie de Fallot)
Congenital heart defect manifested by an inversion of the great vessels,
and a ventricular septal defect.
Familial (French : familial) Relevant to a trait that
is more frequent in members of an affected individual family than in the
general population. This may be caused by genetic or environmental
factors, or both.
Family history (French : histoire familiale) Family
history based on genealogy to identify individuals carriers of or
affected with a trait or genetic disease similar to the propositus
genotype or phenotype.
Family tree (French :
pedigree, histoire familiale) Ancestral information in relation to an
individual or family.
Fibroblast (French : fibroblaste) Young conjonctive
Filling in (French : remplissage) Insertion of
nucleotides in a single DNA strand to make it entirely double stranded.
Finger loop (French : boucle digitale) Image formed by
the epidermal ridges on finger tips. Radial and cubital loops are found
as well as whorls and arches. One notes an excess of arches on the
fingertips in trisomy 18.
Finger printing (French : cartographie peptidique)
Analytical method that supplies an exact identity card of a protein
molecule containing electrophoretic and chromatographic properties of
various polypeptide segments of the molecule.
FISH Fluorescent in situ hybrization (French :
hybridation in situ en fluorescence) A physical mapping approach that
uses fluorescein tags to detect hybridization of probes with metaphase
chromosomes and with the less- condensed somatic interphase chromatin.
Flow cytometry (French : cytométrie de
flux)Analysis of biological material by detection of the light-absorbing
or fluorescing properties of cells or subcellular fractions (i.e.,
chromosomes) passing in a narrow stream through a laser beam. An
absorbance or fluorescence profile of the sample is produced. Automated
sorting devices, used to fractionate samples, sort successive droplets
of the analyzed stream into different fractions depending on the
fluorescence emitted by each droplet.
Flow karyotyping (French : caryotypage de flux) Use of
flow cytometry to analyze and/or separate chromosomes on the basis of
their DNA content.
Fondamental research (French : recherche fondamentale)
Research that studies normal and abnormal physiological processes, while
clinical research is applied to prevention, diagnostic and cure of
Founder effect (French : effet fondateur) The high
frequency of a mutant gene in a rapidly expanding population founded by
a small ancestral group when one or more of the founders were, by
chance, carriers of the mutant gene.
Fragile site (French : site fragile) Non-staining gaps,
known as fragile sites, are occasionally observed in characteristic
sites on several chromosomes.
(French : X-fragile) Common form of X linked mental retardation
associated with a fragile site on X chromosome. The genetic defect has
been identified as an abnormal amplification or more than 60 times of
triple CGG at the Xq27.3 locus. If the child has the disease the mother
can have a pre-mutation with an abnormal amplification between 60-200
repeats of the CGG triplet. The amplification hampers the expression of
gene FMR-1. FRAXA site is not far from FRAXE site, a variant of the
Fragment (French : fragment) Part of a chromosome
detached by breakage : if there is a centromere we refer to a centric
fragment and if not it is called acentric.
Frameshift (French : décalage du cadre de
lecture) A shift in the reading frame used to translate the base
sequence of mRNA. It is caused by the addition or deletion of one or
more bases, resulting in an alternative peptide being formed.
Frameshift mutation (French : mutation de changement de
phase) Change resulting from addition or deletion of nucleotides, in
numbers other than three (French : triplets; codons), which moves the
translation reading frame so that a new set of codons, beyond the point
of abnormality in the messenger RNA, is read.
FRAXA, FRAXE, see: fragile X
Gamete (French : gamète) Mature male or female
reproductive cell, sperm or ovum, with a haploid set of chromosomes or
23 for humans.
G-C, see: base pair.
Gemellity, twinning (French :
gémellité) Simultaneous development of two embryos. It is
univitelline if originating from an egg subdivision or bivitelline if
several eggs were fertilized at the same time.
(French : gène) The
fundamental physical and functional unit of heredity. A gene is an
ordered sequence of nucleotides located in a particular position on a
particular chromosome that encodes a specific functional product : a
protein or RNA molecule.
Gene amplification, see
Gene candidate (French : gène candidat) Gene
suspected to be responsible for the occurrence of a genetic disease.
Gene cluster (French : groupe de gènes) Any
group of two or more closely linked genes on a chromosome that are
Gene construction (French : Construction
génique) Portion of DNA involved in the transfer into a cell
containing an interest gene and the promoter and regulator sequences
essential to its expression and regulation in the receptor cell.
Gene conversion (French : conversion de gène)
Unequal recovery of genetic markers or alleles in the region of the
exchange during genetic recombination. Processes analogous to meiotic
gene conversion in eukaryotes. Changes from heterozygosity to
homozygosity by mechanism other than segregation.
Gene expression (French :
expression génique) The process by which a gene coded information
is converted into the structures present and operating in the cell.
Expressed genes include those that are transcribed into mRNA and then
translated into protein and those that are transcribed into RNA but not
translated into protein.
Gene families (French : familles de gènes)
Groups of closely related genes that make similar products.
Gene flow (French : flux génétique) The
spread of genes from one breeding population to others owing to the
dispersal of gametes or zygotes.
Gene fusion (French : fusion de gènes)
Association of gene fragments leading to the formation of a chimera.
Gene library, see
Gene mapping (French :
cartographie génique) Determination of the relative positions of
genes on a DNA molecule, chromosome or plasmid, and of the distance, in
linkage units or physical units, between them.
Gene product (French : produit génique) The
biochemical material, either RNA or protein, resulting from expression
of a gene. The amount of gene product is used to measure how active a
gene is; abnormal amounts can be correlated with disease- causing
Gene rearrangement (French : réarrangement
génétique) Collection of several pieces of DNA initially
Gene tagging (French : étiquetage
génétique) Insertion of a genetic marker in or close to a
Gene therapy (French : thérapie génique)
Insertion of normal DNA directly into cells to correct a genetic defect.
Gene transfer (French : transfert de gène)
Transfer of genetic material from one cell to another or from one
organism to another.
(French : code génétique) The sequence of nucleotides,
coded in triplets (codons) along the mRNA, that determines the sequence
of amino acids in protein synthesis. The DNA sequence of a gene can be
used to predict the mRNA sequence, and the genetic code can in turn be
used to predict the amino acid sequence.
Genetic competence (French : compétence
génétique) Cellular state that allows penetration of a
foreign nucleic acid.
Genetic complementation, see
Genetic consensus (French : consensus
génétique) Short DNA sequence found in a number of genes
and living organisms.
Genetic construction (French : construction
génique) Portion of DNA needed for the transfer in a cell of a
gene of interest including the promoter and regulators essential to its
expression and regulation in the receiving cell.
Genetic conversion, gene
(French : conversion génique) Non reciprocal genetic
recombination. Interaction between allelic sequences during meiosis
leading to an unequal exchange of genetic information.
Genetic diagnosis (French : diagnostic
génétique) Detection of genes of an organism by
hybridization of its genome with specific molecular probes. Diagnosis of
a genetic disease.
Genetic disease (French : maladie
génétique) Disease due to the mutation of one or several
genes. When only one gene is involved, we refer to a monogenic disease.
Genetic disruption (French : disruption génique)
Interruption of the coding sequence of a gene due to the introduction of
another DNA sequence.
Genetic distance (French : distance
génétique) Degree of filiation between different genomes.
In molecular genetics the genetic distance is measured by the percentage
of structural homology between two sequences by molecular hybridization
or by comparing nucleotide sequences.
Genetic drift (French : dérive
génétique) Any change either directed or undirected in
gene frequency in a population.
Genetic engineering (French : génie
génétique) Manipulations by which an individual having a
new combination of inherited properties is established.
Genetic footprint (French : empreinte
génétique) Fine structural characteristic of a specific
DNA region allowing to identify a specific cell and its association.
Genetic heterogeneity (French :
génétique) Presence of similar phenotypes due to different
Genetic load (French : fardeau génétique)
In humans we refer to hereditary defects which lower life expectancy or
reduce reproduction capacity.
Genetic map, see linkage map.
Genetic material (French : matériel
génétique) See : genome.
Genetic polymorphism (French : polymorphisme
génétique) The regular and simultaneous occurrence in the
same population of two or more alleles at a genetic locus, with at least
one minor allele having a frequency greater than 1%.
Genetically modified organism, GMO
(French : organisme génétiquement modifié, OGM)
Organism of which the genome has been modified. If the reproductive
cells carry the modification they will transmit it to the descents.
Genetics (French : génétique) The study
of the patterns of inheritance of specific traits.
Genic conversion, see:
Genocopy (French : génocopie) The production of
the same phenotype by different genes also called "mimetic
Genome (French : génome)
All the genetic material in the chromosomes of a particular organism;
its size is generally given as its total number of base pairs.
Genome map (French : carte génomique) Research
and technology development efforts aimed at mapping and sequencing some
or all of the genome of human beings and other organisms.
Genome sequencing (French : séquençage du
génome) Determination of the order in which the bases are
arranged within a length of DNA or RNA or, the sequence of amino acids
that make up a protein.
Genomic library, gene bank
(French : banque de gènes) A collection of clones made from a set
of randomly generated overlapping DNA fragments representing the entire
genome of an organism.
Genotype, haplome (French :
génotype) The sum of genetic information or gene contained in the
chromosomes of the individual as distinguished from their phenotype. It
determines not a unique phenotype but a range of phenotype capacities
referred to as an individuals norm of reaction to the environment.
Germinal stem cell, see
Glabella (French : glabelle) Region of the face between
GMO, see: modified organism.
Guanine-G (French : guanine-G) A nitrogenous base, one
member of the base pair G-C or guanine and cytosine).
Haploid (French : haploïde) A single set of
chromosomes: half the full set of genetic material present in the egg
and sperm cells of animals and in the egg and pollen cells of plants.
Human beings have 23 chromosomes in their reproductive cells.
Haplome, see: genotype.
Haplotype (French : haplotype) Genetic material carried
by only one of two chromosomes and corresponding to a specific
Harelip (French : fente labiale) Uni or bilateral
closure defect of the upper lip.
Hare lip and cleft palate (French : gueule de loup,
fente labio-palatine) Hare lip and cleft palate frequently observed in
holoprosencephaly or a chromosomal defect like the trisomy 13.
HAT culture medium (French : milieu de culture HAT) A
tissue culture medium containing hypoxanthine, aminopterin anbd
thymidine, used in somatic cells fusion experiments
HDL, high density cholesterol (French :
cholestérol de haute densité, HDL) Cholesterol transported
by high density lipoproteins.
Helix (French : helix) The margin of the external ear.
Hematopoietic (French :
hématopoïétique) Related to the formation of blood
cells, a process that occurs mainly in the bone marrow.
Hemizygosity (French : hémizygotie) Presence of
a single gene copy in a diploid cell, example : X and Y in the male. In
abnormal situations there may be a deletion on a chromosome or entire
loss of that chromosome leading to a partial or complete deletion, ex
Turner 45X syndrome or the Cri du Chat 5p- anomaly.Heritability (French : héritabilité) That
portion of the character variance due to hereditary factors as distinct
from factors of environment.
(French : hétérochromatine) A fraction of chromatin that
has characteristics distinct from the bulk of the chromosomal material,
Heteroduplex (French : hétéroduplex) A
DNA double helix in which the complementary strands are derived from
different molecules, so that there may be small regions of mismatching.
Heteroduplex technique, mapping (French : technique
dhétéroduplex) Technique that allows to visualize in
electron microscopy non homologous segments of a mutant from the normal
Heterokaryon (French : hétérocaryon) A
cell in which genetically different haploid nuclei may co-exist and
Heteromorphism (French : hétéromorphisme)
Normal morphological variation in chromosome staining.
Heteroplasmy (French : hétéroplasmie)
Presence of more than one type of mitochondria in cells of an individual
: simultaneous presence of normal DNA and mutant mtDNA.
Heteroploidy (French :
hétéroploïdie) Any different chromosome number from
Heterosis (French : hétérosis) Advantage
of heterozygote genotypes over homozygote genotypes of their parents.
Heterozygosity (French :
hétérozygosité) The presence of different alleles
at one or more loci on homologous chromosomes.
(French : hétérozygote composite) Individual who is
heterozygote at two different loci.Hexadactylia (French : hexadactylie) Autosomal dominant
malformation characterized by the presence of a sixth digit on hands and
(French : histone) Basic chromosomal proteins present in eukaryotes
believed to be involved in the coiling and condensation of chromosomes.
Holandric (French : holandrique) Hereditary trait due
to the presence of a gene on Y chromosome. Very few characters are
linked to the Y chromosome. The transmission of the trait is exclusively
from father to son.
Homeobox (French : homéobox) A short stretch of
nucleotides whose base sequence is virtually identical in all the genes
that contain it. It has been found in many organisms from fruit flies to
human beings. In the fruit fly, a homeobox appears to determine when
particular groups of genes are expressed during development.
Homoduplex (French : homoduplex) A DNA molecule with
completely complementary base sequences.
Homologies (French : homologies) Similarities in DNA or
protein sequences between individuals of the same species or among
Homologous chromosomes (French : chromosomes
homologues) A pair of chromosomes containing the same linear gene
sequences, each derived from one parent.
Homologous recombination, see:
Homoplasmy (French : homoplasmie) The presence of a
single population of mt DNA in the cells of a single individual. This is
Homozygous (French : homozygote) Designating a diploid
nucleus, cell or organism that contains two identical alleles for any
Host cell (French : cellule hôte) Cell carrying
foreign genetic material brought by a virus, a plasmid, a recombine DNA
in vitro or an entire cell.Housekeeping gene (French : gène domestique)
Gene that regulates vital functions of all cell types.
HPLC, high pressure liquid chromatography (French :
HPLC, chromatographie liquide à haute performance)
Chromatographic technology used to separate and quantitate mixtures of
substances in solution. The high pressure technique allows a rapid
analysis of complex mixtures.
Human gene therapy (French : thérapie
génique humaine) Insertion of normal DNA directly into cells to
correct a genetic defect.
Human Genome Initiative (French : initiative en
génome humain) Collective name for several projects begun in 1986
by DOE to (1) create an ordered set of DNA segments from known
chromosomal locations, (2) develop new computational methods for
analyzing genetic map and DNA sequence data, and (3) develop new
techniques and instruments for detecting and analyzing DNA. This DOE
initiative supported by the NIH is now known as the Human Genome
Hybrid DNA-RNA (French : hybride ADN-ARN) Double
stranded molecule made of a DNA and a RNA complementary chains.
Hybrid gene, chimeric gene (French : gene hybride) Gene
made of DNA fragments of various origins.
Hybrid selection (French : sélection dhybride)
Selection of a double-stranded DNA molecule with heteroduplex regions.
(French : hybridation) The process of joining two complementary strands
of DNA or one each of DNA and RNA to form a double-stranded molecule.
Hybridization, in situ (French : hybridation in situ)
Hybridization of a specific DNA or RNA probe, marked with cellular DNA
or RNA, on a tissue or fixed cells.
Hybridization on colony (French : hybridation sur
colonie) Hybridization in situ allowing to identify bacteria with a
specific DNA sequence.
Hydrocephaly (French : hydrocéphalie) Fluid
invasion within the cranium. Abnormal enlargement of cerebral
Hydrops, anasarca (French : hydrops) Fetus showing
ascites and abnormal tissue oedema.
Hyperdiploidy (French : hyperdiploïdie) The state
of being hyperploid, or having more than the typical number of
chromosomes in unbalanced sets, as in Downs syndrome.
Hypertelorism (French : hypertélorisme) Abnormal
distance between the two eyes measured at the pupil level.
Hypoploidy (French : hypoploïdie) State of having
lost one or more chromosomes.
Hypothenar (French : hypothenar) The ridge on the palm
along the basis of the fingers and the ulnar region.
Immunofluorescence technique, method (French :
immunofluorescence, méthode) A method determining the location of
antigen or antibody in tissue by the pattern of fluorescence resulting
when the tissue is exposed to the specific antibody or antigen labelled
with a fluorochrome.
Immunosuppression (French : immunosuppression) The
artificial prevention or diminution of the immune response, as by
irradiation or by administration of anti-metabolites, anti-lymphocyte
serum, or specific antibody.
Imprinting, parental see:
Inborn error of metabolism (French : erreur
innée du métabolisme) Genetic metabolic disorder in which
a protein defect produces a metabolic block which may have a deleterious
Incidence (French : incidence) Number of new patients
or individuals who acquired the disease during a certain period of time
in a specific population.
Individual primary recombinant clones (French :
recombinant individuel primaire) Recombinant clones (hosted in phage,
cosmid, YAC or other vector that are placed in two-dimensional arrays in
microtiter dishes. Each primary clone can be identified by the identity
of the plate and the clone location (row and column) on that plate.
Arrayed libraries of clones can be used for many applications, including
screening for a specific gene or genomic region of interest as well as
for physical mapping. Information gathered on individual clones from
physical map analyses is entered into a relational database and used to
construct physical and genetic linkage map simultaneously; clone
identifiers serve to interrelate the multilevel maps.
Induction (French : induction) The starting or
enhancement of synthesis of an enzyme by a cell, taking place upon the
provision of the substrate for the enzyme.
Informatics (French : informatique) The study of the
application of computer and statistical techniques to the management of
information. In genome projects, informatics includes the development of
methods to search databases quickly, to analyze DNA sequence
information, and to predict protein sequence and structure from DNA
Informativity (French : informativité)
Possibility to identify two chromosomes of the same pair in particular
in the region that carries the mutant gene.
Initiation factor (French : facteur dinitiation) Any
class of protein factors which are requisite for the formation of the
initiation complex and the initiation of mRNA translation.
Insert (French : insert) Sequence of foreign DNA
introduced in a specific DNA molecule.
(French : insertion) The acquisition of extra nucleotides within a DNA
sequence. They may affect only one nucleotide, a point mutation, but
they usually affect several nucleotides in the sequence.
Insertion mutation, mutagenesis
(French : mutagénèse par insertion) A mutation that
results from an insertion of one or more nucleotides into the DNA chain.
They can revert to the wild-type state by removal of the extra
sequences. They may change the triplet code reading of genetic
Insertion sequence, see :
In situ hybridization (French : hybridation in situ)
Use of a DNA or RNA probe to detect the presence of the complementary
DNA sequence in cloned bacterial or cultured eukaryote cells.
Integration (French : intégration) Recombination
process that inserts a small DNA molecule into a larger one.
Intercalary (French : intercalaire) Loss of a portion
of a chromosome between two breaks.
Interest gene (French : gène
dintérêt) Gene made of DNA fragments of various origins.
Interferon (French : interferon) A protein that is
synthesized by animal cells in response to viral infection and non
specifically inhibits replication of the viruses. It is found in serum
almost at the onset of the infection and long before the production of
(French : interphase)
The period in the cell cycle when DNA is replicated in the nucleus; it
is followed by mitosis.
Interrupted gene (French : gène discontinu) Gene
made of several alternate series of exons and introns RNA introns are
eliminated during splicing. Differential splicing of introns of an
interrupted gene can give rise to several proteins; one then speaks of
Intragenic recombination (French : recombinaison
intragénique) The process by which progeny derive a combination
of genes different from that of either parent. In higher organisms, this
can occur by crossing over.
Introns, intervening sequence (French : intron) The DNA
base sequences interrupting the protein- coding sequences of a gene;
these sequences are transcribed into RNA but are cut out of the message
before it is translated into protein.
(French : inversion) An abnormality in chromosome structure that results
from a portion of the chromosome becoming detached, rotating through
180o and then becoming attached again.
In vitro (French : in vitro) Occurring outside a living
In vivo (French : in vivo) Taking place in the living
(French : isochromosome, -i) Abnormal chromosome formed by the
duplication of two short arms -ip- or long arms -iq- of equal length and
with identical loci. The other arm is lost.
(French : électrofocalisation) An analytical separation procedure
similar to gel electrophoresis. It is used to separate proteins and
other charged molecules on the basis of their isoelectric point.
IVF, in vitro fertilization (French :
fécondation in vitro, FIV) Fertilization of the ovum by a sperm
outside of the living organism.
IVM, maturation in vitro (French : IVM, maturation in
vitro) see maturation in vitro.
Karyotype (French : caryotype) A photomicrograph of
individual chromosomes arranged in a standard format showing the number,
size, and shape of each chromosome type; used in low- resolution
physical mapping to correlate gross chromosomal abnormalities with the
characteristics of specific diseases.
Kilobase, kb (French : kilobase, kb) Unit of length for
DNA fragments equal to 1000 nucleotides.
Kinetochore, see: centromere.
LDL, low density cholesterol (French : cholesterol de
basse densité, LDL) Cholesterol transported by low density
Leaky (French : partiellement fonctionnel) Said of a
gene mutation which allows some residual level of gene expression.
leptonème) First stage of the first meiotic division.
Lethal factor (French : facteur létal) An
abnormality of the genome that leads to death in utero, ex :chromosomal
Library (French : banque) An unordered collection of
DNA clones from a particular organism whose relationship to each other
can be established by physical mapping.
Ligand (French : ligand) A molecule that can bind to a
receptor and thereby induce a signal in the cell, example: a hormone.
Ligase, DNA (French : ligase, ADN) An enzyme that
creates a phosphodiester bond between the 3 end of one DNA segment and
Ligation (French : ligature) Covalent linkage of a DNA
molecule extremities allowing to reunite by a bridge two DNA molecules
in one single unit.
(French : liaison, groupe de liaison) The proximity of two or more
markers, genes or RFLP markers on a chromosome; the closer together the
markers are, the lower the probability that they will be separated
during DNA repair or replication processes (binary fission in
prokaryotes, mitosis or meiosis in eukaryotes), and hence the greater
the probability that they will be inherited together.
Linkage desequilibrium (French :
déséquilibre de liaison) Situation where two genes or
alleles are more often or less associated in cis in a given population
and for which the frequency departs from expected value according to the
Hardy Weinberg law.
Linkage group (French : groupe de liaison) Group of
genes that seem to be close together according to their hereditary
transmission . They are generally neighbour on the same chromosome.
Linkage map (French : carte de
liaison) A map of the relative positions of genetic loci on a
chromosome, determined on the basis of how often the loci are inherited
together. Distance is measured in centimorgans (cM).
Linker (French : lieur) Synthetic bicatenary
olinucleotide added in vitro to a DNA sequence that brings a new
Localize (French : localiser) Determination of the
location of a gene or other marker on a chromosome.
Localized mutagenesis, see
(French : locus) The
position on a chromosome of a gene or other chromosome marker; also
means the DNA at that position. The use of locus is sometimes restricted
to mean regions of DNA that are expressed.
(French : lod score) The abbreviation for logarithm of the odds. A
measure of the odds ratio obtained by dividing the likelihood that two
loci are linked at a specific recombination fraction by the likelihood
that they are unlinked.
Lymphedema (French : lymphoédème)
Congenital or acquired oedema due to an obstruction of lymphatic
Lymphocyte (French : lymphocyte) Leukocyte which arises
in the lymph glands and the lymph nodes. It has a single nucleus and
Lyon hypothesis, see
Lytic phage (French : phage de
lyse) Any phage that causes host cells to lyse.
Macrocephaly (French : macrocéphalie) Excessive
size of the head.
Macrorestriction map (French : carte de
macrorestriction) Map depicting the order of, and distance between sites
at which restriction enzymes cleave chromosomes.
Malformation (French : malformation) Any morphological
defect present at birth, being apparent or not.
Mapping (French : cartographier) See
Marker (French :
marqueur) An identifiable physical location on a chromosome :
restriction enzyme cutting site, gene whose inheritance can be
monitored. Markers can be expressed regions of DNA (genes) or some
segment of DNA with no known coding function but whose pattern of
inheritance can be determined. Also see
RFLP, restriction fragment length polymorphism.
Marker gene (French : gène marqueur) Gene
expression that allows sorting of cells where it is found.
Maternal inheritance, see:
Maturase (French : maturase) Enzyme that intervenes in
the maturation of pre-m-RNA.Maturation (French : maturation) Modifications of
messengerRNA made of additions and deletions at the time of, or after
Maturation in vitro, IVM
(French : maturation in vitro) To describe the maturation of ova in
Mb, see: megabase.
Megabase, Mb (French :
mégabase, Mb) Unit of length for DNA fragments equal to 1 million
nucleotides and roughly equal to 1 cM.
(French : méiose)
The process of two consecutive cell divisions in the diploid progenitors
of sex cells. Meiosis results in four rather than two daughter cells,
each with a haploid set of chromosomes.
Mendelian inheritance (French :
hérédité mendélienne) Classical heredity as
described by Gregory Mendel in 1866.
Mesoderm (French : mésoderme) One of the three
layers of cells comprising the early embryo. Gives rise to muscle, bone,
connective tissues and blood as well as the vascular and the uro-genital
(French : ARN messager, ARNm) RNA that serves as a template for protein
synthesis. Also see: genetic code.
Metacentric (French : métacentrique) Chromosome
with a more or less central centromere and arms of approximately equal
métaphase) A stage in mitosis or meiosis during which the
chromosomes are aligned along the equatorial plane of the cell.
Methylation (French : méthylation) Chemical
reaction adding a methyl group to a compound. Note the hypermethylation
in the FRA X syndrome leading to FMR1 gene inactivation. May be involved
in the regulation of gene expression.
Microsatellite, minisatellite (French : microsatellite)
Highly polymorphic DNA marker comprised of mononucleotides,
dinucleotides, trinucleotides or tetra-nucleotides that are repeated in
tandem arrays and distributed throughout the genome. The best studied
are the CA <alternatively GT> dinucleotide repeats. They are used
for genetic mapping.
Microcephaly (French : microcéphalie) Head
circumference < 2nd percentile at birth. The other parameters can be
Micrognathia (French : micrognathie) Congenital or
acquired insufficient development of the mandible.
Midface (French : étage moyen de la face) Median
region of the face.
Minicell (French : minicellule) Bacterial cell of
reduced sized that has lost its chromosomal DNA.Minichromosome (French : minichromosome) Unidentified
small chromosome that replicates according to the mitotic cell cycle.
Generally there is only one copy of this chromosome.
Minigene (French : minigène) Gene, reconstructed
for experimental means, from regulating sequences and double strand cDNA
and the corresponding mRNA. A minigene codes directly for mature
mRNA.Miniphage (French : miniphage) Phage, reconstructed for
experimental needs, that has kept part of its functions. Miniplasmid (French : miniplasmide) Plasmid
reconstructed for experimental needs with remaining part of its
Misense mutation (French : mutation non-sens) mutation
that replaces an amino acid codon by a nonsense codon.
Mismatch, misparing (French : mésappariement)
Non pairing of a zone in a fragment of nucleic acid double strand.
Mitogen (French : mitogène) Agent inducing
(French : mitose,
caryocinèse) The process of nuclear division in cells that
produces daughter cells genetically identical to each other and to the
Mitotic index (French : index mitotique) Proportion of
dividing cells in relation to all cells analyzed.
Modification, nucleic acid (French : modification dun
acide nucléique) Any transformation observed in nucleotides after
their assembling into a polynucleotide.
Mixoploidy, see: mosaicism.
Modal number (French : nombre modal) Normal number of
Molecular biology (French : biologie
moléculaire) Study of molecules carrying the hereditary message,
DNA,RNA structure, synthesis, modifications or transformations.
Molecular genetics (French : génétique
moléculaire) Branch of genetics concerned with the molecular
structure and activities of the genetic material, including the
replication of DNA, the transcription into RNA and the translation of
RNA to form proteins.
Molecular hybridization, see :
Monocistronic (French : monocistronique) Descriptive of
messenger RNA molecules that code for one polypeptide chain.
Monoclonal antibodies (French : anticorps monoclonaux)
Homogeneous antibodies produced by a clone of B lymphocytes originating
from a unique mother cell that will generally detect only one genetic
Monolayer (French : monocouche) Tissue culture in
Monosomy (French : monosomie) Presence of only one copy
of a pair or segment of a chromosome.
Monozygocity (French : monozygotie) Twins originating
from the same egg.
Morgan, see: centimorgan.
Morphogenesis (French : morphonogénèse)
Development of forms and structures of the organism.
Morula (French : morule) Name given to the human
fertilized egg after the first divisions or blastomere segmentation. At
this stage the egg is still in the genital tract. Nidation takes place
at the blastocyst stage.
Mosaic (French : mosaïque, myxoploïdie)
Presence of two or more distinct cells in an individual.
mRNA, see messenger RNA.
Mucolipidosis (French : mucopolidose) Group of
hereditry metabolic defects due to the deficiency of enzymes essential
for the degradation of oligosaccharides; unlike mucopolysaccharidoses
they do not excrete abnormal amounts of glysaminoglycans in urine.
Skeletal,cardiac,ocular and systemic deleterious effects are observed in
the affected individuals.
Multifactorial or multigenic disorders (French :
maladies multifactorielles, multigéniques) See
Multigeny (French : multigénie) Genetic property
that presents a phenotype character that is dependant of several genes.
Multiple allelomorphs (French : alleles multiples)
Relative to various possible forms of a gene.
Multiplexing (French : multiplexe) A sequencing
approach that uses several pooled samples simultaneously, greatly
increasing sequencing speed.
Mutagen (French :
mutagène) Any physical or chemical agent significantly increasing
mutational events and thus mutation rates above the spontaneous
background level. Those are induced mutations as opposed to the normally
occurring spontaneous mutations.
Mutagenic (French : mutagène) Capable of
inducing stable, heritable changes in the genetic information of a cell.
Mutagenic agent, see mutagen.
Mutant (French : mutant) Gene that has undergone a
mutation or an individual who carries this mutant gene.
(French : mutation) Any
heritable change in DNA sequence. Compare polymorphism.
neuronal apoptosis inhibitory protein.
Nearest neighbor sequence analysis (French : A
biochemical technique for estimating the frequencies that pairs are next
to one another.
Neuronal apoptosis inhibitory protein,
(French : Protéine inhibitrice de la mort neuronale
programmée) Protein that inhibits the programmed neuronal death.
Neurotropic factors (French : facteurs neurotropiques)
Factors that have some affinity for the nervous tissues.
Nick (French : cassure monocaténaire) Breakage
affecting only one of two strands of a nucleotide double helix.
Nick translation (French : marquage par
déplacement de lencoche) Replaces part of a preexisting strand
of duplex DNA with newly synthesized material.
(French : base
nitrogénique) A nitrogen-containing molecule having the chemical
properties of a base.
Non disjunction (French : non disjonction) Failure of
separation of homologue chromatids at the mitotic anaphase as well as
the second meiotic division. There is desequilibrium of the two sister
alleles or chromosomes.
(French : codon
nonsens) Codon that does not specify an amino acid but indicates the
termination of a polypeptide chain. These codons interrupt the reading
of the messenger RNA (mRNA) strand and also cause release of the
synthesised polypeptide chain.
Nonsense triplet, see:
Northern blot, RNA transfer (French : Northern blot,
transfert dARN) A gel base procedure that locates mRNA sequences on a
gel that are complementary to a piece of DNA used as a probe.
Nucleic acid (French : acide nucléique) A large
molecule composed of nucleotide subunits.
Nucleic acid denaturation (French : dénaturation
dacide nucléique) Conversion of double stranded nucleic acid to
a single strand state.
Nucleic acid sequencing (French : décryptage des
séquences nucléotidiques) Determination of the linear
order of the nucleic basic chains.
Nucleic probe (French : sonde nucléique) DNA or
RNA sequence marked by a fluorescent isotope or enzyme used to detect
homologue sequences by in situ or in vitro hybridization.
(French : nucléosome) Element of chromatin made by the coiling of
140 base pairs on an octamere of histone.
Nucleotide (French :
nucleotide) A subunit of DNA or RNA consisting of a nitrogenous base
(adenine, guanine, thymine, or cytosine in DNA; adenine, guanine,
uracil, or cytosine in RNA), a phosphate molecule, and a sugar molecule
(deoxyribose in DNA and ribose in RNA). Thousands of nucleotides are
linked to form a DNA or RNA molecule. See DNA,
base pair, RNA.
Nucleus (French : noyau) The cellular organelle in
eukaryotes that contains the genetic material.
Null mutation (French : mutation nulle) An allele that
results in either the absence of the gene product or the absence of any
function at the phenotypic level.
Oligogenic diseases (French : maladies
oligogéniques) Diseases or traits that result from the effects of
relatively few genes some of which have relatively large effects.
Omphalocele (French : omphalocèle) Umbilical
Oncogene (French : oncogène) A gene, one or more
forms of which is associated with cancer. Many oncogenes are involved,
directly or indirectly, in controlling the rate of cell growth.
Oocyte (French : ovocyte, oocyte) An immature or
unfertilized ovum, also called the egg.
Open reading frame
(French : cadre de lecture ouvert, ORF) The sequence of DNA or RNA
located between the start-code sequence, or initiation codon and the
stop-code sequence, or termination codon.
Operator (French : opérateur) DNA site to which
a repressor will bind to prevent the transcription of the adjacent
Operon (French : opéron) Transcription unit made
of a promotor, operator and one or more structural genes.
open reading frame.
Overlapping clones (French : clones superposés)
See genomic library.
Overlapping sequence, see:
Ovum (French : ovum) A female germ cell; an egg cell; a
cell which is capable of developing into a new member of the same
species, in animals usually only after maturation and fertilization.
pachytène) Genetic viral material inside an infected cell
Qualifies The third stage of the first meiotic division when chromosomes
are condensed , chromatids of each chromosome are visible. Homologue
chromosomes appear as bivalent.
Packaging (French : encapsidation) Packaging of genetic
viral material inside an infected cell.
Palindromic sequence (French : sequence palindromique)
A nucleotide sequence in which the 5 to 3 sequence of one strand is
the same as that of its complementary strand.
Panmixia (French : panmixie) Large human population
where unions between individuals take place at random. Genotypes depend
on the gene and allele frequencies.
(French : coefficient de parenté) The probability that an
individual has received both alleles of a pair from an identical
ancestral source. Also the proportion of loci at which an individual is
homozygous by descent.
(French : empreinte parentale) The differential expression of genetic
material, at either a chromosomal or an allelic level, depending on
whether the genetic material has been inherited from the male or female
Patent ductus arteriosus (French : persistance du canal
artériel) Congenital heart defect : persistance of the arterial
Patent foramen ovale (French : communication
inter-auriculaire) Congenital heart defect : persistance of the inter
polymerase chain reaction.
PDG, preimplantation diagnosis
(French : diagnostic prenatal pré-implantatoire) Diagnosis of a
disease before the egg implantation.
Pedigree, see family tree.
(French : pénétrance) Frequence with which a trait will
manifest in a family.
Pentasomy (French : pentasomie) State of a cell or
individual that has five copies of a chromosome instead of two. Example
: the 49 XXXXX syndrome.
PEPCK, phosphoenolpyruvate carboxylase enzyme (French :
enzyme phosphoenolpyruvate carboxylase)
Peptide signal, Peptide
(French : peptide, séquence) Segment of 15 to 30 amino acids
present at the N terminal portion of a protein; it indicates to the cell
that this protein must be exported or secreted.
PERV virus (French : virus PERV) Pork virus known as
the endogen pork virus found in the pork genetic material. This
retrovirus can not be identified or eliminated and the laboratory tests
showed that it can infect human cells. We do not know if the retrovirus
can be transmitted via a xenograft.
Phage (French : phage) A virus for
which the natural host is a bacterial cell.
Phage template (French : phage tempéré)
Phage genome can be integrated into the host cell DNA and transform its
properties. 1- if integrated into the host cell genome it is called
prophage and 2- the template phage has the capacity to lyse the bacteria
that it infects.
(French : S phase)
Interphase which usually lasts much longer than mitosis is itself
divided into stages. Of the interphasic stages, Gap 1 (G1) which lies
between the end of telophase and the beginning of the Synthesis (S)
periods is the longest; DNA synthesis takes place during the S period.
Phenocopy (French : phénocopie) A mimic of a
phenotype that is usually determined by a specific genotype, produced
instead by the interaction of some environmental factor with a different
Phenotype (French : phénotype) The biochemical
physiological and morphological characteristics of an individual as
determined by his or her genotype and the environment in which it is
Philtrum (French : philtrum) Region of the upper lip
bordered by two tissue pillars.
Phosphodiester (French : phosphodiester) Molecule that
has one phosphate and two ester functions.
Physical map (French : carte
physique) A map of the locations of identifiable landmarks on DNA (e.g.,
restriction enzyme cutting sites, genes), regardless of inheritance.
Distance is measured in base pairs. For the human genome, the lowest-
resolution physical map is the banding patterns on the 24 different
chromosomes including X and Y chromosomes the highest- resolution map
would be the complete nucleotide sequence of the chromosome.
Phytohemagglutinin (French :
phytohémagglutinine) Polysaccharide substance extracted from red
beans that has the capacity to agglutinate red cells and facilitate
their separation from leukocytes. It also has the property to stimulate
lymphocyte division and blastic transformation. This property is used in
cytogenetic studies done on cultured lymphocytes.
Pierre Robin syndrome (French : syndrome de Pierre
Robin) Syndrome involving the abnormal closure of the palate and the
inferior mandible that is too small.
Placebo (French : placebo) Inactive substance
substituted for a medication in order to distinguish between the
psychological and pharmacological effects.
Placental mosaicism, see:
confined placental mosaicism.
Plasmid (French : plasmide) Autonomously replicating,
extra chromosomal circular DNA molecules, distinct from the normal
bacterial genome and non essential for cell survival under non selective
conditions. Some plasmids are capable of integrating into the host
genome. A number of artificially constructed plasmids are used as
Plasmid incompatibility (French :
incompatibilité plasmidique) The inability of two different
plasmids to coexist in the same host cell.
Plasmid Ri (French : plasmide
Ri) Plasmid carried by the bacteria Agrobacterium rhizo-genes that has a
transferable DNA segment and that can be integrated into the genome of a
vegetable host cell. It can serve as transformation vector to produce
Plasmide Ti (French : plasmide Ti) Plasmid carried by
the bacteria Agrobacterium rhizo-genes that has a DNA segment
transfeerable and has the property to integrated into the DNA of a
vegetable host cell . Ti means tumor inductor.
(French : pléïotropie) Multiple phenotypic effects of a
single gene or gene pair. The term is used particularly when the effects
are ordinarily thought to be unrelated.
Ploidy (French : ploïdie) A term referring to the
number of chromosome sets per cell. Example : haploid; diploid;
Pluripotent stem cell, see :
Point mutation (French : mutation ponctuelle) Mutation
interesting only one base. Addition or deletion are mutation mechanisms.
Polar body (French : globule polaire) Hypoploid cell
resulting from the first two meiotic divisions. It contains mainly
nuclear material, the cytoplasmic material being reserved for the
ovocyte and the ovotid.
Polar mutation (French : mutation polaire) Mutation in
one gene that reduces the expression of one gene further from the
promoter in the same operon. Nonsence mutations frequently are polar.
Poly A tail, polyadenylated end, polyA region (French :
séquence polyA) Long segment of adenosine polymerized
monophosphates present at the 3 end of eukaryotes mRNAs.
Polydactyly (French : polydactylie) Presence of one or
more fingers, or duplication of one finger or toe.
(French : maladies polygéniques) Genetic disorders resulting from
the combined action of alleles of more than one gene like heart disease,
diabetes, and some cancers). Although such disorders are inherited, they
depend on the simultaneous presence of several alleles; thus the
hereditary patterns are usually more complex than those of single- gene
Polymerase chain reaction,
(French : réaction en chaîne de la polymérase, PCR)
A method for amplifying a DNA base sequence using a heat- stable
polymerase and two 20- base primers, one complementary to the (+)-
strand at one end of the sequence to be amplified and the other
complementary to the (-)- strand at the other end. Because the newly
synthesized DNA strands can subsequently serve as additional templates
for the same primer sequences, successive rounds of primer annealing,
strand elongation, and dissociation produce rapid and highly specific
amplification of the desired sequence. PCR also can be used to detect
the existence of the defined sequence in a DNA sample.
Polymerase, DNA or RNA (French : polymérase, ADN
ou ARN) Enzymes that catalyze the synthesis of nucleic acids on
preexisting nucleic acid templates, assembling RNA from ribonucleotides
or DNA from deoxyribonucleotides.
Polymorphism (French : polymorphisme) Difference in DNA
sequence among individuals. Genetic variations occurring in more than 1%
of a population would be considered useful polymorphisms for genetic
Polypeptide chain termination (French : Terminaison de
la chaîne peptidique) End of the proteic chain.
Polyploidy (French : polyploïdie) Cells, tissues
or individuals that have more than a diploid set of chromosomes.
Triploid and tetraploid embryos are non viable, they are often found in
(French : polyribosome)
Complex made of a mRNA molecule and ribosomes. The protein synthesis
takes place on this complex.
Prader Willi syndrome, see: Angelman syndrome.
Precursor RNA, see
Preimplantation diagnosis, see PDG.
Pre messenger RNA, Heterogeneous nuclear
(French : Pré ARN messager) The probable precursor of messenger
RNA, mRNA, so named because its size distribution is heterogeneous and
its location is strictly nuclear; no base sequences have been found in
cytoplasmic mRNA that are not also pre-messenger RNA.
Premutation (French : prémutation) Stage of
expansion mechanism in which the mucleotide expansion is above normal
but still insufficient to translate into clinical manifestations. For
instance in myotonic dystrophy a 50 to 80 triplet repeat is considered
as a premutation.
Prevalence (French : prévalence) Frequency of a
disease in a population, counting both old and new cases.
Primer (French : amorce) Short preexisting
polynucleotide chain to which new deoxyribonucleotides can be added by
Proband, see propositus.
Probe (French : sonde)
Single-stranded DNA or RNA molecules of specific base sequence, labeled
either radioactively or immunologically, that are used to detect the
complementary base sequence by hybridization.
Processing RNA, post transcriptional
(French : maturation de lARN) Modifications of messengerRNA made of
additions and deletions at the time of transcription.
Prognathism (French : prognathisme) Excessive
development of the lower jaw.
Prokaryote (French : procaryote) Cell or organism
lacking a membrane- bound, structurally discrete nucleus and other
subcellular compartments. Bacteria are prokaryotes.
Promoter (French : promoteur) A site on DNA to which
RNA polymerase will bind and initiate transcription.
Prophage (French : prophage)
Sequence of phage DNA.
Propositus, proband (French :
proband, propositus) The family member through whom the family is
ascertained. If the propositus is affected, he may be called the index
Prosome (French : prosome) Small RNA particle
associated with a free messenger RNA repressed in the cytoplasm.
protéine) A large molecule composed of one or more chains of
amino acids in a specific order; the order is determined by the base
sequence of nucleotides in the gene coding for the protein. Proteins are
required for the structure, function, and regulation of the body cells,
tissues, and organs, and each protein has unique . Examples are hormones, enzymes, and antibodies.
Protein design (French : remodelage) Creation of a
protein with new properties by directed mutagenesis or gene synthesis.
Protein, structural (French : protéine de
structure) A protein that serves a structural role in the body such as
Proteomics (French : protéomique) New discipline
derived from genomics that concerns research activities aimed at the
collection of all available information on gene expression of organisms
with an identified genome.
Protooncogen (French : protooncogène) A normal
gene that with a slight alteration by mutation or other mechanism
becomes an oncogene.
Provirus (French : provirus) The state of a virus in
which it integrates into and replicates in coordination with a host cell
chromosome and thus is transmitted from one cell generation to another.
Pseudoautosomal (French : pseudoautosomique) The distal
tip of the Y chromosome short arm, which undergoes crossover with the
distal tip of the X chromosome short arm during meiosis in the male.
Pseudodiploidy (French : pseudodiploïdie) Apparent
diploid cell. The karyotype is abnormal, although it carries 46
Pseudogene (French : pseudogène) The sequence of
pseudogene is similar to the structural gene but does not code for a
Pseudohermaphrodite (French : pseudohermaphrodite)
Individual whose gonadal and phenotypic sex differ.
Pterygium colli, webbed neck (French : pterygium colli,
cou palmé) A thick fold of skin on the lateral side of the neck,
extending from the mastoid region to the acromion, producing a
congenital webbed neck.
Ptosis (French : ptose) Paralytic drooping of the upper
Puff, see: chromosome puff.
Pulse labelling (French : marquage de brève
durée) An experimental technique in which cells or cell extracts
are exposed for a short time to a compound labelled with a radio active
Purine (French : purine) A nitrogen- containing,
single-ring, basic compound that occurs in nucleic acids. The purines in
DNA and RNA are adenine and guanine.
Purine base (French : base purique) Adenine and
Pyrimidic base (French : base pyrimidique) Cytosine and
Pyrimidine (French : pyrimidine) A nitrogen-containing,
double- ring, basic compound that occurs in nucleic acids.The
pyrimidines in DNA are cytosine and thymine; in RNA, cytosine and
Quadriradial pattern (French : image quadriradiale)
Structure shaped as a cross made of homologue or non homologue
chromosomes observed when a translocation takes place during a mitotic
Quasidominance (French : quasidominance) The pattern of
inheritance produced by the mating of an affected homozygote individual
heterozygous for the same recessive trait so that homozygous affected
members appear in two or more successive generations.
Rare-cutter enzyme, see
restriction enzyme cutting site.
Receptor (French : récepteur) A transmembrane or
intracellular protein involved in transmission of a cell signal.
Recessive (French : récessif) A trait or gene
that is only expressed in homozygotes or hemizgotes.
Recombinant (French : recombiné) An individual
who has a new recombination of genes not found together in either
parent. Usually applied to linkage analysis.
Recombinant aneusomia (French : aneusomie de
recombinaison) Presence of a duplication or deletion resulting from a
crossing over in an inverted loop.
Recombinant clones (French : clones recombinants)
Clones containing recombinant DNA molecules. See
recombinant DNA technologies.
Recombinant DNA molecules (French : molécules
dADN recombinant) A combination of DNA molecules of various origins
that are joined using recombinant DNA technologies.
(French : technologies dADN recombinant) Procedures used to join
together DNA segments in a cell- free system (an environment outside a
cell or organism). Under appropriate conditions, a recombinant DNA
molecule can enter a cell and replicate there, either autonomously or
after it has become integrated into a cellular chromosome.
Recombinant genetic (French : recombinant
génétique) Any of the individual or cells arising as a
result of inter-chromosomal and intra-chromosomal,via crossing-over or
conversion, genetic recombination.
Recombinant plasmid (French : plasmide
recombiné) Plasmid in which a foreign DNA fragment has been
Recombinant protein (French : protéine
recombinée, recombinante) Protein synthesised from a transgene.
Recombination frequencies (French : fréquences
de recombinaison) Instance when the progeny derive a combination of
genes different from that of either parent. In higher organisms, this
can occur by crossing over.
(French : recombinaison homologue) Insertion of a transgene in a
particular site in lieu of a of a nervous cell specific gene.
Recombination, intragenic (French : recombinaison
intragénique) The process by which progeny derive a combination
of genes different from that of either parent. In higher organisms, this
can occur by crossing over.
Regulation, autogenous (French : régulation
autogène) Regulation system where the gene product controls its
Regulation mutation (French : mutation de
régulation) Mutation that affects the regulation of one or more
gene expression, without affecting the coding segment.
Regulatory gene (French : gène de
régulation) A gene coding for a protein that regulates other
Regulatory regions or sequences (French :
régions régulatrices ou séquences) A DNA base
sequence that controls gene expression.
Reject (French : rejet) Immunological reaction against
a tissue or organ. Elimination by the receiver of the transplanted
tissue or organ.
Release factor (French : facteur de terminaison) Any of
the special protein factors which recognize the terminator codons UAA,
UAG, and UGA in messenger RNA and stimulate the codon specific release
of polypeptides from ribosomes during genetic translation.
Renaturation of nucleic acid (French : renaturation
dacide nucléique) The return by slow conversion of a denatured
nucleic acid or protein to its native configuration.
Repeat unit (French : unité de
répétition)DNA sequence constituting the basic motive in a
Replication fork (French : fourche de
réplication) A Y shaped point at which two strands of a DNA
molecule are unwound and separated during replication.
Replicon (French : réplicon) Any genetic element
- bacterial chromosome, virus, genome, plasmid - that behaves as an
autonomous unit of replication.
Repressor (French : répresseur) Protein
synthesised by a regulator gene, which, by binding to a specific site on
DNA, the operator gene of an operon, prevents the formation of messenger
RNA by the operons other structural genes and hence stops protein
Reproduction, assisted technology ART (French :
reproduction assistée, ART) (assisted reproduction technology,
ART) Technology that concerns one or several steps of intervention
during the process of in vitro reproduction.
Resistance factor, R factor, R plasmid, resistance plasmid
(French : facteur de transfert de résistance) Plasmid that codes
for one or more enzymes inactivating one or more toxic agents or
Resolution (French : résolution) Degree of
molecular detail on a physical map of DNA, ranging low to high.
Restriction (French : restriction) Mechanism by which a
cell degrades foreign DNA.
Restriction enzyme cutting
(French : site de coupure de lenzyme de restriction) A specific
nucleotide sequence of DNA at which a particular restriction enzyme cuts
the DNA. Some sites occur frequently in DNA (e.g., every several hundred
base pairs), others much less frequently (rare- cutter; e.g., every
10,000 base pairs).
Restriction enzyme, endonuclease (French : enzyme de
restriction, endonucléase) A protein that recognizes specific,
short nucleotide sequences and cuts DNA at those sites. Bacteria contain
over 400 such enzymes that recognize and cut over 100 different DNA
Restriction fragment length polymorphism,
(French : Variation between individuals in DNA fragment sizes cut by
specific restriction enzymes; polymorphic sequences that result in RFLPs
are used as markers on both physical maps and genetic linkage maps.
RFLPs are usually caused by mutation at a cutting site.
(French : rétinoblastome) The retinoblastoma, uni or bilateral is
an embryonic tumor of the retina. The gene locus for the retinoblastoma
is located in the 13q14.1-14.2 region. In the proximal region of the
long arm of chromosome 13. The tumor can be hereditary due to a germinal
mutation or sporadic due to a somatic mutation.
Retrognathism (French : rétrognathisme) Small
inferior mandible in a retro position.
Retrograde transport (French : transport
rétrograde) Transport going in the other direction. Example: from
the muscle to the nerve.
Retroinhibition (French : inhibition par
rétroaction) Regulator system in which the terminal product of a
biosynthetic chain of reactions stops the activity of the first enzyme
of this chain.
Retrotransposon (French : rétrotransposon) Class
of transposon of which the transposition requires the inverse
transcription of their transcription product
Retrovirus (French : rétrovirus) A virus with an
RNA genome that propagates by conversion of the RNA into DNA by the
enzyme reverse transcriptase.
Reverse genetics (French : génétique
réverse) The application of human gene mapping to clone the gene
responsible for a particular disease when no information about the
biochemical basis of the disease is available.
Reverse mutant (French : mutant réverse)
Organism resulting from a reverse mutant.
Reverse transcriptase (French : réverse
transcriptase) An enzyme used by retroviruses to form a complementary
DNA sequence , cDNA, from their RNA. The resulting DNA is then inserted
into the chromosome of the host cell.
Reversion (French : réversion) Mutation that
restores a function annulled by a first mutation.
restriction fragment length polymorphism.
RI plasmid, see plasmid RI.
Ribonucleic acid, RNA (French : acide
ribonucléique, ARN) A chemical found in the nucleus and cytoplasm
of cells; it plays an important role in protein synthesis and other
chemical activities of the cell. The structure of RNA is similar to that
of DNA. There are several classes of RNA molecules, including messenger
RNA, transfer RNA, ribosomal RNA, and other small RNAs, each serving a
Ribosomal proteins (French : proteins ribosomales) A
group of protein slinked to rRNA by non covalent bomds giving to the
ribosome a tridimention structure.
Ribosomal RNA, rRNA (French : ARN ribosomal, ARNr ) A
class of RNA found in the ribosomes of cells.
Ribosomes (French : ribosomes) Small cellular
components composed of specialized ribosomal RNA and protein; site of
protein synthesis. See ribonucleic acid (RNA).
(French : chromosome en anneau) Structurally abnormal chromosome in
which the end of each chromosome arm has been broken and the broken arms
reunited to form a ring.
RNA, see ribonucleic acid.
RNA processing, see :
RNA replicase (French : ARN synthétase) ARN
réplicase (RNA replicase) Enzyme of RNA viruses that catalyses
the reproduction or replication of this molecule.
RNA satellite (French : ARN satellite) RNA that may be
found in some viruses.
Sanger method, Sanger sequencing (French :
méthode de Sanger) A widely used method to determine the order of
bases in DNA.
Satellite DNA (French : satellite, ADN) Molecular : a
portion of DNA that differs enough in base composition so that it forms
a distinct band on cesium chloride gradient centrifugation; usually
contains highly repetitive sequences. Cytogenetics: small mass of
chromatin located at the extremity of the short arm of acrocentric
chromosomes above a small constriction.
Segregation (French : ségrégation)
Separation of two alleles on a locus at meiosis.
Sequence (French : séquence) See
Sequence amplified (French : séquence
amplifiée) Increased number of intra or extrachromosomic DNA
Sequence, coding (French :
séquence codante) Segment of a gene that directly defines the
amino acid sequence of the corresponding protein.
Sequence consensus (French : séquence consensus)
Specific sequence of a given region of a nucleic acid or a protein in
which each position represents the base or the amino acid most commonly
Sequence highly repeated (French : séquence
hautement répétée) DNA sequence present in a great
number of copies in the genome.
(French : séquence dinsertion) DNA element showing transposition
from one region of the genome to another.
Sequences, inverted repeat (French : séquences
répétées inverses) Identical or almost identical
sequences present in several copies in the same DNA molecule with an
Sequence leader (French : séquence de
tête) Sequence found upstream of the initiation codon of
traduction of RNA messengers.
Sequence, non coding (French : séquence non
codante) Part of a gene that does not directly define the amino acid
sequence of the corresponding protein.
(French : séquence chevauchante) DNA sequence carrying the
information related to several genes using a different reading frame.
Sequence, palindromic (French : séquence
palindromique) Sequence of DNA that is the same when one strand is read
right to left; consists os adjacent inverted repeats.
Sequence poly A (French : séquence polyA) Long
segment of polymerized adenosine monophosphates present at the
3extremity of mRNA of eukaryotes.Sequence repeat (French : séquences
répétées directes) Multiple copies of the same base
sequence on a chromosome; used as a marker in physical mapping.
Sequence signal (French : séquence signal) DNA
sequence that can be read the same way in both directions in relation to
a central point : on the same strand example : ATTGC,CGTTA, or on both
strands AAGTT and TTGCAA.
Sequence tagged site, STS
(French : courte séquence dADN) Short (200 to 500 base pairs)
DNA sequence that has a single occurrence in the human genome and whose
location and base sequence are known. Detectable by polymerase chain
reaction, STSs are useful for localizing and orienting the mapping and
sequence data reported from many different laboratories and serve as
landmarks on the developing physical map of the human genome. Expressed
sequence tags (ESTs) are STSs derived from cDNAs.
Sequence, tandem repeat (French : séquences
répétées en tandem) Multiple copies of the same
base sequence on a chromosome; used as markers in physical mapping.
Sequence, unique (French : unique séquence)
Selection of a monocatenary nucleic acid after formation of a hybrid
molecule with a complementary strand.
Sequence untranslated (French : séquence non
traduite) A region of mRNA that is not used in the synthesis of an amino
acids sequence of a given peptide or protein. They usually appear at
either end of the sequence that codes for the amino acid sequence.
Sequencing (French : séquençage)
Determination of the order of nucleotides (base sequences) in a DNA or
RNA molecule or the order of amino acids in a protein.
Sex chromatin, Barr body
(French : chromatine sexuelle, corpuscule de Barr) Chromatin mass
present in interphase nuclei of women and most female mammals
representing one of the two Xs that is inactivated.
Sex chromosomes (French : chromosomes sexuels) The X
and Y chromosomes in human beings that determine the sex of an
individual. Females have two X chromosomes in diploid cells; males have
an X and a Y chromosome. The sex chromosomes comprise the 23rd
chromosome pair in a karyotype.
Shotgun cloning or method (French : méthode
à laveugle) Cloning of DNA fragments randomly generated from a
genome Sequencing method that involves randomly sequenced cloned pieces
of the genome, without knowledge of where the piece originally came
from. This can be contrasted with "directed" strategies, in
which pieces of DNA from known chromosomal locations are sequenced.
Because there are advantages to both strategies, researchers use both
random (or shotgun) and directed strategies in combination to sequence
the human genome.
Siblings (French : germains) Brothers and sisters;
couples own children.
Sibship (French : fratrie) All the sibs in a family.
Signal peptide, see
(French : silenceur)
DNA region located near a gene that has the capacity to reduce its
Silent mutation (French : mutation silencieuse) A
mutant gene that has no phenotypic effect.
Simian crease (French : pli simiesque) Transverse and
unique palmar crease frequently found in trisomy 21.
Single-gene disorder (French : maladie
monogénique) Hereditary disorder caused by a mutant allele of a
single gene. Examples : Duchenne muscular dystrophy, retinoblastoma,
sickle cell disease.
Single stranded loop (French : boucle
monocaténaire à brin unique) Non pairing loop.
Sister chromatid exchange, SCE (French : échange
de chromatides soeurs) Exchange of equivalent material between two
chromatids of a maternal or paternal chromosome.This is not an exchange
between homologue chromosomes and it happens only in the first meiotic
division by crossing over.
Site specific mutagenesis (French :
mutagénèse dirigée) Introduction of a precise
mutation in a cloned DNA fragment followed by the reinsertion of the
mutant sequence in the original gene to replace the corresponding wild
SKY, see: Spectral karyotype SKY.
SMA, spinal muscular atrophy (French : amyotrophie
spinale infantile) Neuromuscular disease.
SMN Survival motor neurone.
SNRNP, small nuclear ribonucleoprotein (French : petite
ribonucléoprotéine nucléaire) Protein induced in
the cytoplasm, that has affinity with the survival motor neuron, that
plays a role in DNA splicing.
Somatic cell genetic mutation A change in the genetic
structure that is neither inherited nor passed to offspring. Also called
Somatic cell mutation (French : mutation somatique) A
change in the genetic structure that is neither inherited nor passed to
offspring. Also called acquired mutation.
Somatic cells (French : cellules somatiques) Any cell
in the body except gametes and their precursors.
Somatic mutation (French : mutation somatique) Mutation
in a cell that is not germinal.
(French : marquage Southern) Transfer by absorption of DNA fragments,
separated in electrophoretic gels, to membrane filters for the detection
of specific base sequences by radio labelled complementary probes.
Spacer, DNA (French : espaceur) Untranslated DNA
sequence separating genes in repeat units.
Species (French : espèce) Branch of natural
sciences that concerns similar individuals that can reproduce within
Spectral karyotype SKY A graphic of
all an organisms chromosomes, each labelled with a different color.
Useful for identifying chromosomal abnormalities.
Sperm (French : sperme) The male sex cell
Spinal (French : spinal) Pertaining to the spine or
Spliceosome (French : spliceosome) Ribonucleoproteic
protein formed at the time of transcripts splicing
Splicing (French : épissage) The introduction of
donor DNA into a vector for cloning
Splicing, mRNA (French : épissage, ARNm) The
natural process by which transcribed mRNA matures to become mRNA that
will be translated.
Staining region homogeneously (French : région
de coloration homogène) Chromosome region that has a uniform
(French : codon
dinitiation) A codon that codes for the first amino acid in a
Stem cell (French :
cellule souche) Pluripotent cell giving rise to cells with a different
function. The origin can also be embryonic or germinal. Example:
undifferentiated, primitive cells in the bone marrow that have the
ability both to multiply and to differentiate into specific blood cells.
Stenosis, arterial (French : sténose
artérielle) Narrowing of an arterial vessel.
Stop codon (French : codon
non-sens) see nonsense codon.
Stop signal (French : signal stop) Signal indicating
the end of a gene.
Structural gene (French : gene de structure) A gene
coding for any RNA or protein product.
Structural genomics (French : génomique de
structure) The effort to determine the 3D structures of large numbers of
proteins using both experimental techniques and computer simulation.
sequence tagged site.
Submetacentric (French : submétacentrique) A
chromosome with an off-center centromere and arms of clearly different
Substitution (French : substitution) In genetics, a
type of mutation due to replacement of one nucleotide in a DNA sequence
by another nucleotide or replacement of one amino acid in a protein by
another amino acid.
Suppression intergenic, mutation (French : suppression
intergénique) Recuperation of a lost function with the help of a
second mutation localized on a gene other than the initial mutant.
Suppression intragenic (French : suppression
intragénique) A compensation mutation inside the mutant gene that
will that will restaure its activity. The second mutation interests the
first gene mutation but in a different site.
Suppressor gene A gene that can suppress the action of
Suppressor mutation (French : mutation suppressive)
Gene action suppressed by another gene.
Synapsis (French : appariement, synapse) Pairing
between homologous chromosomes of maternal and paternal origin during
the prophase of meiosis, leading to the formation of gametes. Contact
zone between two neurones or one neurone and a muscular glandular cell,
through which the electric or chemical transmission is completed.
Synaptonemal complex (French : complexe
synaptonémal) Electron micrographs of paired chromosomes at the
pachytene stage of meiosis.
Syndrome (French : syndrome) The group or recognizable
pattern of symptoms or abnormalities that indicate a particular trait or
Syngeneic (French : syngénique) Genetically
identical members of the same species.
Synteny (French : synténie) The physical
presence together on the same chromosome of two or more gene loci,
whether or not they are close enough together for linkage to be
System, acellular (French
: système acellulaire) void of cells but containing the necessary
elements for a specific synthesis, like nucleic acids, precursors,
enzymes except substances to be tested in tissue extracts.
Tandem repeat sequences (French : séquences
répétées en tandem) Multiple copies of the same
base sequence on a chromosome; used as a marker in physical mapping.
(French : boîte
TATA) A conserved A-T rich heptamer found about 25 bp before the start
point of each eucaryotic RNA polymerase II transcription unit.
Technology transfer (French : transfert technologique)
The process of converting scientific findings from research laboratories
into useful products by the commercial sector.
Telocentric (French : télocentrique) Centromere
located at the very end of a chromosome.
(French : télomère) The ends of chromosomes. These
specialized structures are involved in the replication and stability of
linear DNA molecules. See DNA replication.
Template, RNA or DNA (French : matrice dARN ou ADN)
The base sequences found in nucleic acids that serve as the basis for
the synthesis of complementary strrands of DNA or RNA.
Teratogen (French : tératogène) Substance
or agent that can induce congenital malformations by action on the
embryo. Thalidomide is a teratogenic agent.
Teratoma (French : tératome) Tumoral formation
of embryonic origin made of tissues of endoderm,ectoderm and mesoderm
origin in which we may find nervous cells, hair, teeth that have no
connection with the surrounding tissues.The teratoma are sometime called
twins with an imperfect development.
Terminal transferase (French : transférase
terminale) Enzyme that has the capacity to add a desoxy ribonucleotide
in the 3OH of a DNA strand.
terminateur) DNA sequence that initiates the end of the transcription.
Tetraploidy (French : tétraploïdie)
Cellular content is made of 4n or 92 chromosomes.
Tetravalent (French : tétravalent) When two
chromosomes are translocated in the first meiotic division; there is
then a four chromosome formation called tetravalent instead of two
bivalent homologue chromosomes.
Thenar (French : éminence thénar) Dermal
ridges between the 5th finger and the wrist.
Thymine,T (French : thymine,T ) A nitrogenous base, one
member of the base pair A- T<adenine- thymine>.
Totipotent, cells (French : cellules totipotentes)
Cells of the very early embryo that have the capacity to differentiation
into the placenta the embryo and all post-embryonic tissues and organs.
No stem cell line to date has been able to show these properties.
Trait (French : trait) Element transmitted by heredity.
Recessive character present in a heterozygote form, like for instance
the thalassemia trait.
Trans control (French : contrôle en trans)
Regulation of genetic expression that manifests through an intermediate
Transcriptase reverse (French : transcriptase inverse)
Enzymatic complex present in RNA viruses assuring the DNA synthesis from
transcription) The synthesis of an RNA copy from a sequence of DNA or
gene; the first step in gene expression.
(French : site dinitiation de la transcription) Exact site of the
initiation of transcription.
unité de transcription) Region of the genome located between an
initiation site and a site of termination of the transcription by the
Transcriptional readthrough (French : lecture
transcriptionnelle) Uninterrupted DNA transcription.
Transducing phage (French : phage transducteur) A virus
particle that accidentally contains a very small portion of its host
chromosome, used in . They can
program other strains of bacteria to manufacture proteins they normally
Transductor phage (French : phage transducteur) Phage
that has the property to transfer part of a genome from the host cell to
Transfection (French : transfection) A gene that upon
transfection converts a previously immortalized cell to the malignant
(French : ARN
de transfert, ARNt) A class of RNA having structures with triplet
nucleotide sequences that are complementary to the triplet nucleotide
coding sequences of mRNA. The role of tRNAs in protein synthesis is to
bond with amino acids and transfer them to the ribosomes, where proteins
are assembled according to the genetic code carried by mRNA.
Transformation (French : transformation) A process by
which the genetic material carried by an individual cell is altered by
incorporation of exogenous DNA into its genome.
Transgene (French : transgène) Gene introduced
in the genome of an organism by genetics engineering.
Transgenesis (French : transgénèse)
Operation that consists in producing transgenic organisms.
Transgenic, animal (French : animal
transgénique) In reference to a living organism which foreign DNA
has been introduced in all or the majority of his cells. The estrange
gene can be transmitted to descents. Animal conceived to bear a gene
from another animal.
Transient expression (French : expression transitoire)
Expression of a gene trecently introduced into a cell and not yet
integrated into the genome.
Transition (French : transition) A mutation in which
either purine is substituted for the other, A for G or G for A or one
pyrimidine is substituted for the other C for T or T for C.
traduction) The process of forming a specific protein having its own
amino acid sequence determined by the codons of the messenger RNA. The
ribosome and transfer RNA are necessary for this process.
Translation error, reading mistake (French : erreur de
traduction) Incorrect placement of one or more amino acid residues in a
polypeptide chain during genetic translation.
Translational control (French : contrôle de la
traduction) The regulation of gene expression at the level of genetic
Translational readtrough (French : translecture
traductionnelle) Translation of a mRNA at ahead of the normal
Translocation (French : translocation) The transfer of
a segment of one chromosome to another chromosome.
Translocation, balanced (French : translocation
équilibrée) The transfer of a segment of one chromosome to
another without loss or addition of chromosomal material.
Translocation, insertional (French : translocation
insertionnelle) The transfer of a segment of one chromosome to another
chromosome by insertion of the segment following two breaks in the
chromosome followed by reunion of the chromosome segments involved.
(French : translocation réciproque) Exchange of chromosome pieces
between two non homologous chromosomes.
(French : translocation robertsonienne) Translocation of two acrocentric
chromosomes by fusion at or near the centromere, with loss of the short
Transposase (French : transposase) Enzyme coded by a
gene carried by a transposable involved in the transposition.Transposition (French : transposition) Change of
position of a DNA fragment in the genome.
Transposon (French : gène sauteur, transposon)
DNA fragment susceptible to move from one location to another in the
Transversion (French : transversion) A mutation in
which either purine is substituted for either pyrimidine or vice versa.
Tricuspid atresia (French : atrésie
tricuspidienne) Atresia of the heart pulmonary valve between the right
cardiac auricle and the right ventricle.
Triplet, nonsense, see :
(French : diandrie, triploïdie, digynie) A cell with three copies
of each chromosoome or an individual made up of such cells.
Triradius (French : triradius) Point of origin of
dermal ridges in 3 directions.
Trisomy (French : trisomie) The state of having three
representatives of a given chromosome instead of the usual pair, as in
trisomy 21 or Down syndrome.
Tropism cellular (French : cellular tropism) Property
of a virus to infect a cell type preferentially. True hermaphrodyte (French : hermaphrodisme vrai)
Hermaphrodyte individual who has gonadal tissue of both sexes.
Trunctus arteriosus (French : trunctus arteriosus)
Congenital heart anomaly caracterized by the presence of only one
arterial structure giving rise to aortic and pulmonary branches.
Tumor suppressor gene (French : Gène suppresseur
de tumeur) A normal gene involved in the regulation of cell growth.
Recessive mutations can lead to tumor development, as in the
retinoblastoma gene or the p53 gene.
Tumor transformation (French : transformation tumorale)
Conversion of eucaryotic cells into a stase of unrestrained growth in
culture resembling or identical with the tumorigenic condition.
Twinning, see gemellity.
Ubiquitar molecule (French : molecule ubiquitaire)
Molecule that is present in several tissues of the body.
Unequal crossing over
(French : malségrégation) Crossing over between similar
DNA sequences that are misaligned, resulting in sequences with deletion
or duplication of DNA segments. A cause of a number of genetic variants.
Unequal division, see:
unequal crossing over.
(French : disomie uniparentale) Presence in a diploid cell of two
homologue chromosomes inherited from the same parent. The most common
mechanism is probably the correction of a trisomic cell.
Uracil, U (French : uracil, U) A nitrogenous base
normally found in RNA but not DNA. Uracil is capable of forming of
forming a base pair with Adenine.
Vector (French : vecteur) See
Vector, expression (French : vecteur dexpression)
Vector that has a region that allows the insertion of a gene coding
sequence between the signals essential for its expression.Ventricular septal defect (French : communication
inter-ventriculaire) Congenital heart defect. Persistance of a
communication between the two ventricles.
Villi, see :
chorionic villi sampling.
Virulent phage, see
Virus (French : virus) A noncellular biological entity
that can reproduce only within a host cell. Viruses consist of nucleic
acid covered by protein; some animal viruses are also surrounded by
membrane. Inside the infected cell, the virus uses the synthetic
capability of the host to produce progeny virus.
Virus defective (French : virus défectif) Mutant
virus that can reproduce only in the presence of an assistant virus.
Virus, helper (French : virus assistant) A defective
gene that uses single-stranded RNA as its genetic material. It is only
able to replicate when a helper virus is present in the same host cell.
Virus VONC (French : virus
VONC) Gene originating from a proto-oncogene and subsequently
recuperated by a virus.
VLSI (French : VLSI) Very large-scale integration
allowing over 100,000 transistors on a chip.
VONC, see virus Vonc.
Wild (French : sauvage) The normal allele of a rare
mutant gene, sometimes symbolized by +.
Williams, syndrome (French : syndrome de Williams)
Whorl (French : tourbillon) Dermatoglyphic pattern
observed on the finger tips.
Xenograft (French : xénogreffes) Living cells,
tissues and organs used in the xenografts Transfer of cells, tissues and
organs between two organisms that belong to different species.
Xenotransplantation (French :
xénotransplantation) Transfer of cells, tissues or living organs
from living animals to humans for medical purposes.
X fragile, see Fragile X.
YAC (French : YAC) See
yeast artificial chromosome.
Yeast artificial chromosome,YAC
(French : chromosome artificiel de levure,YAC) A vector used to clone
DNA fragments (up to 400 kb); it is constructed from the telomeric,
centromeric, and replication origin sequences needed for replication in
yeast cells. Also see : cloning vector,
Zinc finger proteins
(French : proteines à doigt de zinc) Transcription activator
proteins, containing finger like structures containing zinc atoms.
Zoonoses (French : zoonoses) Animal diseases that can
be transmitted to humans in living conditions. Animals and humans can be
infected by zoonoses. Examples: rabies, brucellosis, mad cow disease or
Creutzfeldt-Jakob disease in humans
Zygote (French : zygote) A fertilized egg formed as the
result of the union of male and female sex cell -sperm and egg-.
SELECTED REFERENCES :
Le génie du génome. Glossaire http://www.nature.ca/genome/02/022_pqr_f.cfm
Conseil de recherches médicales du Canada. et al.
Vocabulaire du génie génétique :
anglais-français avec index des termes français.
Bibl. sc./Réf. Sc. & génie et Bibl. sc./Réf.
Sc. santé et Bibl. Sc. hum. & soc./Réf. P 305 C132 28
Université Laval biochimie médical-biochimie ouvrage de
Université Laval. Ressources en génétique.
Dictionnaires, Encyclopédies, Glossaires & Lexiques.http://www.bibl.ulaval.ca/ress/genetiquedictionnaires.html
Institut Pasteur Terminologie du génie génétique -
Lexique anglais - français http://www.pasteur.fr/recherche/DicoAF.html
Human genome project information, Genome glossaryhttp://www.ornl.gov/TechResources/Human_Genome/publicat/primer/glossary.html
Glossaries : Human Genetics/Genome Projecthttp://www.kumc.edu/gec/glossary.html
Terminologie du génie génétiquehttp://www.ens-lyon.fr/RELIE/PCR/glossary/glossary.htm
Terminologie Génétique - Glossairehttp://www.globenet.org/myonet/GENETIQUE/glossaire.html
Le grand dictionnaire terminologique, Office Québécois de
la langue françaisehttp://www.granddictionnaire.com/btml/fra/r_motclef/index800_1.asp
Schlindweins B. Hypermedia Glossary Of Genetic Termshttp://hal.weihenstephan.de/genglos/asp/genreq.asp?list=1
GeneTests (National Institute of Health)http://www.genetests.org/servlet/access?qry=ALLTERMS&db=genestar&fcn=term>report2=true&id=8888891&key=xFQGcJD8Bd6xV
Atlas of Genetics and Cytogenetics in Oncology and Haematology 2004-11-01
Glossary of Medical and Molecular Genetics
Online version: http://atlasgeneticsoncology.org/teaching/30028/glossary-of-medical-and-molecular-genetics