t(2;3)(p15-23;q26-27) ?/MECOM

2005-08-01   Jean-Loup Huret 

1.Genetics, Dept Medical Information, University of Poitiers, CHU Poitiers Hospital, F-86021 Poitiers, France
2.Clinical Cytogeneticist, UMC St. Radboud, Dept. Human Genetics, Div. Cytogenetics, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands

Clinics and Pathology


Myeloid malignancies: myelodysplastic syndrome (MDS) in 1/4 of cases, with various FAB diagnoses (refractory anaemia (RA), RA with ringed sideroblasts (RARS), RA with excess of blasts (RAEB), RAEB in transformation (RAEB-t), and chronic myelomonocytic leukemia (CMML)), acute myeloid leukaemia (AML) in 60% of cases (M2-AML in 1/4 of all cases), blast crisis of a chronic myelogenous leukaemia (BC-CML) in about 10% of cases


1/4 of cases were therapy related leukemias, and 10% were BC-CML cases


At least 50 cases described; sex ratio: 1.33 M/F; median age around 50 yrs, most patients being between 30 and 70 yr old (range 3-80 yrs).


High platelet count, dysmegakaryopoiesis, and multilineage dysplasia in 80 to 90% of cases


Median survival 12 months (range 1-53 mths), with a few patients surviving with bone marrow transplantation.



Heterogeneous breakpoints by cytogenetic and FISH analysis; FISH mapping of 2p breakpoints was very heterogeneous ranging from p14 or p15 to p23; FISH mapping of the 3q breakpoint was within the EVI1-MDS region (between RP11-694D5 (centromeric) and RP11-362K14 (telomeric) in the great majority of cases.

Additional anomalies

Sole anomaly in 40%, associated with -7 in 30%, with del(5q) in 15%, with del(7q) in 10%, with t(9;22)(q34;q11) in 10%, and with a complex karyotype in 20% of cases.

Genes Involved and Proteins

Molecular analysis has been performed in only a very few cases. In most of these, ectopic expression of EVI1 was demonstrated, but rare cases seem not to involve this gene. Therefore, characteristics of EVI1 involvement (high platelet count, multilineage dysplasia, monosomy 7, prior history of carcinogen exposure and a poor prognosis) may not be present in further cases with apparently the same breakpoints.
The gene(s) involved in chromosome 2 is/are unknown
Gene name
MECOM (Ecotropic Viral Integration Site 1 (EVI1) and Myelodysplastic Syndrome 1 (MDS1-EVI1)
There is a direct correlation between mapping of the 3q breakpoint in the above given EVI1-MDS region and EVI1 ectopic expression by RT-PCR. Rare case with 3q break outside this interval failed to show ectopic expression of EVI1.
Dna rna description
EVI1 contains 12 exons.
Protein description
EVI1 may play an important role in organogenesis, cell migration, cell growth, and differentiation.


Pubmed IDLast YearTitleAuthors
89319991996Cytogenetic analysis in patients with primary myelodysplastic syndromes in leukaemic transformation. A report on 94 cases. Groupe Français de Cytogénétique Hématologique (GFCH).
66900211984Preliminary data on the in vitro proliferation pattern and karyotypic characteristics in cells of patients with ANLL.Barbieri D et al
78895041995Translocation (2;3)(p22;q28) is associated with myeloid disorders.Berger R et al
40635251985Rearrangements of chromosome 3 involving bands 3q21 and 3q26 are associated with normal or elevated platelet counts in acute nonlymphocytic leukemia.Bitter MA et al
119603922002Structural rearrangements of chromosome 3 in 57 patients with acute myeloid leukemia: clinical, hematological and cytogenetic features.Charrin C et al
20139771991Molecular diagnosis of Philadelphia negative CML using the polymerase chain reaction and DNA analysis: clinical features and course of M-bcr negative and M-bcr positive CML.Dobrovic A et al
86252691996Translocation (2;3)(p13;q26) in two cases of myeloid malignancies. Acute myeloblastic leukemia (M2) and blastic phase of chronic myeloid leukemia.Fleischman EW et al
101986251999Translocation (2;3)(p21;q26) as the sole anomaly in a case of primary myelofibrosis.Herens C et al
86839921996Abberant cytogenetic evolution pattern of Philadelphia-positive chronic myeloid leukemia treated with interferon-alpha.Johansson B et al
15552001992t(2;3)(p13;q26) in a case of chronic myeloid leukemia. Importance of the involvement of 3q26.Kwong YL et al
86160641996t(2;3)(p23;q26) in a patient with AML M2.Levaltier X et al
119642742002Distinct clinical outcomes for cytogenetic abnormalities evolving from aplastic anemia.Maciejewski JP et al
657586019833q-, 3q+ anomaly in malignant proliferations in humans.Mecucci C et al
119795482002Spectral karyotyping in patients with acute myeloid leukemia and a complex karyotype shows hidden aberrations, including recurrent overrepresentation of 21q, 11q, and 22q.Mrózek K et al
107799952000Secondary leukemia in a child with neuroblastoma while on oral etoposide: what is the cause?Ng A et al
72725061981Nonrandom chromosome abnormalities in acute leukemia and dysmyelopoietic syndromes in patients with previously treated malignant disease.Rowley JD et al
150851642004Translocation t(2;3)(p15-23;q26-27) in myeloid malignancies: report of 21 new cases, clinical, cytogenetic and molecular genetic features.Stevens-Kroef M et al
38910741985The 5q-anomaly.Van den Berghe H et al
33379041988Cytogenetic studies in patients with secondary leukemia/dysmyelopoietic syndrome after different treatment modalities.Whang-Peng J et al
66923341984Recurrent chromosomal defects are found in most patients with acute nonlymphocytic leukemia.Yunis JJ et al
86523791996Cytogenetic clonality analysis: typical patterns in myelodysplastic syndrome and acute myeloid leukaemia.van Lom K et al



There are 2 subtypes of the t(2p;3q); in one type the breakpoint on chromosome 2 is assigned to bands 2p21-23, whereas the breakpoint for the other type of breakpoint is localized at 2p15-21.
Atlas Image
Partial GTG (Marian Stevens-Kroef, left) and RFA (Anne Hagemeijer, right) banded karyotypes of t(2;3)( p15-23;q26-27) with the distal (A) and proximal (B) breakpoint on chromosome 2.


Jean-Loup Huret

t(2;3)(p15-23;q26-27) ?/MECOM

Atlas Genet Cytogenet Oncol Haematol. 2005-08-01

Online version: http://atlasgeneticsoncology.org/haematological/1274/t(2;3)(p15-23;q26-27)

Historical Card

2004-05-01 t(2;3)(p15-23;q26-27) ?/MECOM by  Marian Stevens-Kroef 

Clinical Cytogeneticist, UMC St. Radboud, Dept. Human Genetics, Div. Cytogenetics, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands

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