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.

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.

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).

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.

IGH/BCL11A IGH (14q32.33) BCL11A (2p16.1) M t(2;14)(p16;q32)