t(2;14)(p13-16;q32) IGH/BCL11A

2010-02-01   Adriana Zamecnikova 

1.Kuwait Cancer Control Center, Laboratory of Cancer Genetics, Department of Hematology, Shuwaikh, 70653, Kuwait
2.Genetics, Dept Medical Information, University of Poitiers, CHU Poitiers Hospital, F-86021 Poitiers France

Clinics and Pathology

Disease

Identified predominantly in B-cell malignancies, including CLL/SLL, found in 20 cases of chronic lymphocytic leukemia (CLL), 1 B-prolymphocytic leukemia, 1 diffuse, mixed small/large cell non Hodgkin lymphoma (NHL); 8 cases of acute lymphocytic leukemia (ALL): one T-ALL and 7 B-ALL (two in association with t(1;19), one in Ph+ ALL, one with 3-way translocation); two AML (Ph+ M1 and inv(16)) cases and in one Ph+ CML case.
CLL cases are characterized by marrow involvement, absolute lymphocytosis, lymphadenopathy, atypical morphologic features; prolymphocytes may be increased. Serum lactate dehydrogenase and beta-microglobulin levels are elevated, ZAP70 is expressed.
IgVH genes are unmutaded; most cases are positive for CD5, CD19 and CD23; weak intensity of immunoglobuline and CD20, weak or negative CD79b, CD22, absence of FMC-7.

Epidemiology

Sex ratio: CLL cases 10 males and 6 females patients, 4 unknown; adults : aged 40-68 years,, and 3 children aged 6, 10 and 15 years; ALL cases (3 males, 5 females) were 1 adult 37 years old and 7 children aged 1-17 years; 2 AML cases (1 male, 1 female) were 34 and 45 years old; the CML case was a 21 years old male patient.

Prognosis

8 CLL cases were dead after 27-145 months survival; from available data on 3 ALL cases : the y were all dead (one after 15 months, 2 after bone marrow transplantation).

Genes Involved and Proteins

Gene name
BCL11A (B-cell lymphoma/leukemia 11A)
Location
2p16.1
Dna rna description
Originally assigned to region 1, band 3, 2p13; it has subsequently been reassigned to 2p16.1.
Protein description
BCL11A/EVI9 is a zinc-finger protein, containing 6 Krüppel C2H2 zinc fingers as well as a proline-rich domain between zinc fingers 1 and 2 and an acidic domain between 3 and 4. 835 amino acids; 91197 Da, alternative splicing: 6 isoforms, sharing a common N-terminus. Originally named EV19 human homolog BCL11A; high level of conservation across a wide range of species; highly homologous to another gene (BCL11B) on chromosome 14q32.1; like BCL11A, BCL11B is remarkable in having a large 5 CpG island. Predominantly expressed in brain and hematopoietic cells, expression is tightly regulated during B-cell development; low-level or undetectable BCL11A RNA expression in most adult tissues. BCL11A is a DNA sequence-specific transcriptional repressor, an essential factor in lymphopoiesis, required for B-cell formation in fetal liver.
Gene name
IGH (Immunoglobulin Heavy)
Location
14q32.33

Result of the Chromosomal Anomaly

Oncogenesis

Juxtaposition of IgH enhancer elements leading to inappropriate overexpression of the partner gene product. BCL11A may be activated through chromosomal translocation or amplification, leading to myeloid leukemias in mice and lymphoid malignancies in humans; the conserved N-terminus of BCL11A. deregulated expression of BCL11A may play a major role in the pathogenesis; gains and amplifications of the region of chromosome 2p13-16 have been reported in B-cell malignancies, REL, a NF-kappaB gene family member, mapping within the amplified region is coamplified with BCL11A in B-NHL cases and HD lymphoma cell lines; with gains and amplifications, BCL11A interacts directly with BCL6, that serves a crucial role in lymphocyte development, also involved in IG translocations.
The structure of the t(2;14) translocation is a "head-to-head" arrangement, with the breakpoints falling centromeric to the first exon adjacent to a large CpG island at the 5 end; BCL11A is deregulated as a consequence of the translocation, suggesting that BCL11A may be involved in lymphoid malignancies through either chromosomal translocation or amplification.

Bibliography

Pubmed IDLast YearTitleAuthors
94449331997In B-cell chronic lymphocytic leukaemia chromosome 17 abnormalities and not trisomy 12 are the single most important cytogenetic abnormalities for the prognosis: a cytogenetic and immunophenotypic study of 480 unselected newly diagnosed patients.Geisler CH et al
24929041989Nonrandom rearrangement of chromosome 14 at band q32.33 in human lymphoid malignancies with mature B-cell phenotype.Nishida K et al
117193822001The BCL11 gene family: involvement of BCL11A in lymphoid malignancies.Satterwhite E et al
104363011999A plasma cell leukemia patient showing bialleic 14q translocations: t(2;14) and t(11;14).Sonoki T et al
29103651989Immunophenotype-karyotype associations in human acute lymphoblastic leukemia.Uckun FM et al
38755681985A 14;19 translocation in B-cell chronic lymphocytic leukemia: a new recurring chromosome aberration.Ueshima Y et al
15510731992t(2;14)(p13;q32): a recurring abnormality in lymphocytic leukemia. A Pediatric Oncology Group study.Watson MS et al
193696252009Chronic lymphocytic leukemia With t(2;14)(p16;q32) involves the BCL11A and IgH genes and is associated with atypical morphologic features and unmutated IgVH genes.Yin CC et al
22959511990Childhood chronic lymphocytic leukemia with (2;14) translocation.Yoffe G et al

Summary

Fusion gene

IGH/BCL11A IGH (14q32.33) BCL11A (2p16.1) M t(2;14)(p16;q32)
Atlas Image
(A) Partial karyotype showing the t(2;14)(p13;q32) Top - Courtesy Adriana Zamecnikova; Middle and below - Courtesy Melanie Zenger and Claudia Haferlach. (B) Fluorescence in situ hybridization with LSI IgH/MYC and LSI ALK probe showing the juxtaposition of ALK (fusion signal) from 2p23 to the region proximal to IgH locus (green signal) on chromosome 14 and translocation of IgH segments to der(2) chromosome resulting in a green signal on rearranged chromosome 2 - Courtesy Adriana Zamecnikova.

Citation

Adriana Zamecnikova

t(2;14)(p13-16;q32) IGH/BCL11A

Atlas Genet Cytogenet Oncol Haematol. 2010-02-01

Online version: http://atlasgeneticsoncology.org/haematological/1231/t(2;14)(p13-16;q32)

Historical Card

2002-06-01 t(2;14)(p13-16;q32) IGH/BCL11A by  Jean-Loup Huret 

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

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