Atlas of Genetics and Cytogenetics in Oncology and Haematology


Home   Genes   Leukemias   Solid Tumours   Cancer-Prone   Deep Insight   Case Reports   Journals  Portal   Teaching   

X Y 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 NA

t(7;17)(q11;q21) GTF2I/RARA in APL

Written2014-11Guang-Sen Zhang
Department of Hematology/Institute of Molecular Hematology, The Second Xiang-Ya Hospital, Central South University, Changsha, Hunan, 410011, P.R of China; E-mail: zgsllzy@163.com

Abstract Review on t(7;17)(q11;q21) GTF2I/RARA in acute promyelocytic leukaemia, with data on clinics, and the genes involved.

Keywords acute promyelocytic leukaemia; GTF2I; RARA; t(7;17)(q11;q21)

(Note : for Links provided by Atlas : click)

Identity

ICD-Topo C420,C421,C424 BLOOD, BONE MARROW, & HEMATOPOIETIC SYS
ICD-Morpho 9861/3 AML with mutated NPM1; AML with mutated CEBPA; Acute myeloid leukaemia, NOS
Atlas_Id 1711
Other namescryptic t(7;17)(q11;q21) GTF2I/RARA in acute promyelocytic leukaemia (APL)
 
  G-banding karyotype of del(7q). No distinct chromosome tranlocation.

Clinics and Pathology

Disease variant acute promyelocytic leukemia with ATRA resistance
Phenotype / cell stem origin HLA-DR-, CD34-, CD13+, CD33+, CD64+.
Epidemiology One case reported so far. A 35-year old male.
Clinics The patient exhibited leukocytosis and coagulopathy.
Cytology The cytoplasm was occupied by densely packed coarse granules. The nuclei were relatively regular. Auer rods and fagot cells were absent. MPO staining is strongly positive.
 
Mophorlogy of GTF2I-RARA variant APL. Wright Giemsa staining. Image acquired at x1000 magnification.
Treatment ATRA in combination with anthracycline-based chemotherapy did not induce remission. Neither are conventional chemotherapy and ATRA in combination with arsenics. No morphology differentiation of blast cells was seen after ATRA treatment.
Evolution No remission was obtained after ATRA and conventional chemotherapy. The patient died of intracranial hemorrhage on day 143 without remission.
Prognosis Bad.

Cytogenetics

Note Cryptic translocation. FISH studies are needed to uncover the rearrangment.
 
  Metaphase fluorescence in situ hybridization (FISH). On the left, PML-RARA dual colour, dual-fusion translocation probes found RARA rearrangement. The RARA signals are shown in red, while PML signals are shown in green. Intact RARA and PML are shown as (r) and (p), while the split RARA signals are indicated as (s).In the middle, probes specific for the chromosome 7 centromere (GLP D7S486 probes, green) and 7q31 (CSP7 probes, red) confirmed the deletion of the long arm of one chromosome 7. On the right, the combined application of chromosome 7 probes and PML-RARA probes found that one split RARA was translocated to the truncated long arm of chromosome 7. Signal detection was carried out on metaphases according to the manufacturers protocols (Jinpujia, Beijing, China).

Genes involved and Proteins

Gene Name GTF2I
Location 7q11
Note General transcription factor IIi
Protein GTF2I is a ubiquitously expressed phosphoprotein with broad roles in transcription and signal transduction involving growth factor signalling, cell cycle regulation, and transforming growth factor, beta 1(TGFB1) signalling, ER stress response pathway, calcium signalling, and immune signalling (Roy, 2012).
Gene Name RARA
Location 17q21
Note Retinoic acid receptor alpha
Protein RARA is a nuclear retinoic acid receptor that regulates transcription in a ligand-dependent manner. This gene has been implicated in regulation of hemopoietic cells differentiation.

Result of the chromosomal anomaly

Hybrid gene
Note In-frame fusion of exon 6 of GTF2I to exon 3 of RARA
Transcript 5'GTF2I-3'RARA. No reciprocal 5'RARA-3'GTF2I.
Detection Reverse transcript polymerase chain reaction.
  
Fusion Protein
 
  Schematic diagram of RARA, GTF2I and GTF2I-RARA fusion protein. A black line indicates the break point. DBD, DNA-binding domain; LBD +DD, ligand-binding domain and dimerization domain; LZ, leucine zipper; NLS, nuclear localization signal; BR, basic region; R1-R6, I-repeat domains.
Description The fusion transcript encodes a 598 amino acids chimera containing the 195 amino-terminal amino acids of GTF2I, including the N-terminal leucine zipper and the first I-repeat domain, and 403 carboxyl-terminal amino acids of RARA, including the DNA and ligand binding domains.
Expression Localisation Two patterns of GTF2I-RARA localization were observed: diffuse nuclear distribution with a micropunctate pattern, and aggregation in the cytoplasm as macrogranules.
Oncogenesis GTF2I-RARA chimera possesses common features of APL related fusion proteins: the same RARA portion, the ability to self-associate, dominant-negative regulation of the retinoic acid response element, and aberrant subcellular localization.
  

To be noted

Additional cases are needed to delineate the epidemiology of this rare entity:
you are welcome to submit a paper to our new Case Report section.

Bibliography

GTF2I-RARA is a novel fusion transcript in a t(7;17) variant of acute promyelocytic leukaemia with clinical resistance to retinoic acid
Li J, Zhong HY, Zhang Y, Xiao L, Bai LH, Liu SF, Zhou GB, Zhang GS.
Br J Haematol. 2014 Oct 4. doi: 10.1111/bjh.13157. [Epub ahead of print]
PMID 25284716
 
Biochemistry and biology of the inducible multifunctional transcription factor TFII-I: 10 years later.
Roy AL.
Gene. 2012 Jan 15;492(1):32-41. doi: 10.1016/j.gene.2011.10.030. Epub 2011 Oct 21
PMID 22037610
 

Citation

This paper should be referenced as such :
Zhang GS
t(7;17)(q11;q21) GTF2I/RARA in APL;
Atlas Genet Cytogenet Oncol Haematol. in press
On line version : http://AtlasGeneticsOncology.org/Anomalies/t0717q11q21ID1711.html


Translocations implicated (Data extracted from papers in the Atlas)

 t(7;17)(q11;q21) GTF2I/RARA

External links

Mitelman databaset(7;17)(q11;q21) [Case List]    t(7;17)(q11;q21) [Association List] Mitelman database (CGAP - NCBI)
arrayMapTopo ( C42) Morph ( 9861/3) - arrayMap (UZH-SIB Zurich)  [auto + random 100 samples .. if exist ]   [tabulated segments]
 
 
Disease databaset(7;17)(q11;q21) GTF2I/RARA in APL
REVIEW articlesautomatic search in PubMed
Last year articlesautomatic search in PubMed
All articlesautomatic search in PubMed


© Atlas of Genetics and Cytogenetics in Oncology and Haematology
indexed on : Fri Jan 27 12:50:59 CET 2017


Home   Genes   Leukemias   Solid Tumours   Cancer-Prone   Deep Insight   Case Reports   Journals  Portal   Teaching   

For comments and suggestions or contributions, please contact us

jlhuret@AtlasGeneticsOncology.org.