t(2;3)(p21;q26) THADA/MECOM

2013-11-01   Jean-Loup Huret  

1.Genetics, Dept Medical Information, University of Poitiers, CHU Poitiers Hospital, F-86021 Poitiers, France

Clinics and Pathology

Disease

Acute myeloid leukemia (AML)

Epidemiology

One case to date, a 59-year old male patient with a M4-AML (Trubia et al., 2006).

Prognosis

Clinical outcome in cases with the t(2;3)(p16;q26) BCL11A/MECOM and the case with the t(2;3)(p21;q26) THADA/MECOM (plotted together) was severe: "One patient is alive with active disease at 12 months, five patients died after 4-14 months" (Trubia et al., 2006).

Note

MECOM was overexpressed.

Genes Involved and Proteins

Gene name
THADA (THADA, armadillo repeat containing)
Location
2p21
Protein description
THADA is assumed to be involved it in the TRAIL-induced apoptosis. Truncated THADA have been found in thyroid adenomas; it would compete with normal THADA, thereby disturbing normal apoptosis of follicular cells (Rippe et al., 2003; Kloth et al., 2011).
Gene name
MECOM (Ecotropic Viral Integration Site 1 (EVI1) and Myelodysplastic Syndrome 1 (MDS1-EVI1)
Location
3q26.2
Note
MECOM is also known as EVI1 or PRDM3; MECOM symbol means: "MDS1 and EVI1 complex locus".
Protein description
"EVI1" contains two domains of seven and three zinc finger motifs, respectively, a repression domain between the two sets of zinc fingers, and an acidic domain at its C-term. Sequence specific DNA binding protein. Interacts with transcriptional coactivators, corepressors, and other sequence specific transcription factors. MECOM ("MDS1-EVI1") also contains a PR domain from "MDS1" in N-term (Wieser, 2008).

Result of the Chromosomal Anomaly

Description

Regulatory sequences were transferred telomerically to MECOM.The t(2;3) brings about the juxtaposition at 3q26 of the MECOM locus with regulatory elements normally located in proximity of the 2p breakpoints, with consequent EVI1 overexpression, without the formation of a fusion protein.

Article Bibliography

Pubmed IDLast YearTitleAuthors
220506382011Decrease in thyroid adenoma associated (THADA) expression is a marker of dedifferentiation of thyroid tissue.Kloth L et al
129550912003Identification of a gene rearranged by 2p21 aberrations in thyroid adenomas.Rippe V et al
166190482006Characterization of a recurrent translocation t(2;3)(p15-22;q26) occurring in acute myeloid leukaemia.Trubia M et al

Summary

Note

This translocation is found in a subset of cases described in the card t(2;3)(p15-23;q26-27). Other subsets involve other genes, such as BCL11A in the t(2;3)(p16;q26) BCL11A/MECOM.

Citation

Jean-Loup Huret

t(2;3)(p21;q26) THADA/MECOM

Atlas Genet Cytogenet Oncol Haematol. 2013-11-01

Online version: http://atlasgeneticsoncology.org/haematological/1665/haematological-explorer/deep-insight-explorer/js/template.js