i(5)(p10) in acute myeloid leukemia

2010-12-01   Nathalie Douet-Guilbert , Nathalie Douet-Guilbert , Nathalie Douet-Guilbert , Nathalie Douet-Guilbert , Nathalie Douet-Guilbert , Nathalie Douet-Guilbert , Nathalie Douet-Guilbert , Nathalie Douet-Guilbert 

1.Laboratory of Histology, Embryology,, Cytogenetics, Faculty of Medicine, Health Sciences, Université de Bretagne Occidentale, 22, avenue Camille Desmoulins, CS 93837, F-29238 Brest cedex 3, France
2.MLL Münchner Leukümielabor GmbH, Max-Lebsche-Platz 31, 81377 München, Germany

Clinics and Pathology

Phenotype stem cell origin

Type 1: classified as myelodysplastic syndrome (4 cases), acute myeloid leukemia (4 cases) predominantly AML M2;
Type 2: classified as acute myeloid leukemia (5 cases), predominantly AML M5a.

Etiology

Unclear

Epidemiology

Type 1: it is found in young adults in MDS (average age: 35 years; range: 19-67) and in older patients in AML (average age: 66 years; range: 50-85).
Type 2: the +i(5)(p10) is found in patients with an average age of 48.5 years (range : 24-78).

Prognosis

Prognosis of patients with i(5)(p10) seems to be poor compared to patients with del(5q), but it is unclear due to the very small number of cases and the usually associated complex chromosomal abnormalities.

Cytogenetics

Atlas Image
A - FISH with partial chromosome painting 5p (pcp 5p) (Green signal) and 5q (pcp 5q) (Red signal).
B - FISH with LSI 5p15.2 (Green signal) / 5q31 (Red signal). Nathalie Douet-Guilbert.

Cytogenetics morphological

The formation of i(5p) results from the loss of the long arm of chromosome 5 and duplication of its short arm inducing trisomy 5p and monosomy 5q in type 1 and tetrasomy 5p in type 2.
A metacentric del(5q) could be an isochromosome of the short arm of chromosome 5. FISH technique with specific probes of chromosome 5p/5q used as a complement of conventional karyotype is necessary to identify i(5)(p10). The i(5p) is a variant of del(5q). The i(5p) is monocentric or dicentric.

Additional anomalies

In one case, i(5)(p10) was the sole anomaly but rapidly evolved into a complex karyotype. Complex karyotypes were present in the other cases: -12/del12p (3 cases), -17/del17p (2 cases), del9q (2 cases).
Supernumerary +i(5)(p10) was accompanied by several additional anomalies, especially trisomy 8

Genes Involved and Proteins

Note
Type 1: to explain the specific phenotype of i(5)(p10), loss of tumor suppressor genes in the deleted region (5q) associated with gene dosage effect of genes located on 5p is suggested.
Type 2: gene dosage effect of genes located on the short arm of chromosome 5.

Bibliography

Pubmed IDLast YearTitleAuthors
146159112004Myelodysplastic syndrome (RARS) with +i(12p) abnormality in a patient 10 months after diagnosis and successful treatment of a mediastinal germ cell tumor (MGCT).Christodoulou J et al
92049751997Chromosomal breakpoints and changes in DNA copy number in refractory acute myeloid leukemia.El-Rifai W et al
206205962010Isochromosome 5p and related anomalies: a novel recurrent chromosome abnormality in myeloid disorders.Herry A et al
108659862000Lack of BCR/ABL reciprocal fusion in variant Philadelphia chromosome translocations: a use of double fusion signal FISH and spectral karyotyping.Markovic VD et al
167246702006Gain of an isochromosome 5p: a rare recurrent abnormality in acute myeloid leukemia.Panani AD et al
150851632004RT-PCR and FISH analysis of acute myeloid leukemia with t(8;16)(p11;p13) and chimeric MOZ and CBP transcripts: breakpoint cluster region and clinical implications.Schmidt HH et al
114080742001Gain of an isochromosome 5p: a new recurrent chromosome abnormality in acute monoblastic leukemia.Schoch C et al
95921831998Cytogenetic analysis of de novo acute myeloid leukemia with trilineage myelodysplasia in comparison with myelodysplastic syndrome evolving to acute myeloid leukemia.Tamura S et al

Summary

Note

In literature, two types of i(5)(p10) are observed:
Type 1: i(5)(p10) inducing a loss of the long arm of chromosome 5 (5q) and a trisomy of the short arm of the chromosome 5 (5p);
Type 2: +i(5)(p10) (or supernumerary i(5)(p10) or gain of i(5)(p10)) inducing a tetrasomy of the short arm of chromosome 5 (5p). The i(5)(p10) occurred in addition to two normal chromosomes 5.
The isochromosome of the short arm of chromosome 5 - i(5)(p10) - has only been described in a few cases of myeloid leukemia.
Atlas Image
i(5)(p10) G-banding - Claudia Schoch (left), and R-banding - Nathalie Douet-Guilbert (right).

Citation

Nathalie Douet-Guilbert ; Nathalie Douet-Guilbert ; Nathalie Douet-Guilbert ; Nathalie Douet-Guilbert ; Nathalie Douet-Guilbert ; Nathalie Douet-Guilbert ; Nathalie Douet-Guilbert ; Nathalie Douet-Guilbert

i(5)(p10) in acute myeloid leukemia

Atlas Genet Cytogenet Oncol Haematol. 2010-12-01

Online version: http://atlasgeneticsoncology.org/haematological/1376/i(5)(p10)-in-acute-myeloid-leukemia

Historical Card

2005-02-01 i(5)(p10) in acute myeloid leukemia by  Claudia Schoch 

MLL Münchner Leukümielabor GmbH, Max-Lebsche-Platz 31, 81377 München, Germany

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