t(3;6)(q27;p22) HIST1H4I/BCL6

2012-12-01   Jean-Loup Huret 

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

Clinics and Pathology

Disease

Non Hodgkin lymphoma

Clinics

Apparently 6 cases have been described: a case of follicular mixed small cleaved and large cell lymphoma, a case of follicular large cell lymphoma, and 3 cases of diffuse large B-cell lymphoma (Akasaka et al., 1997; Akasaka et al., 2000; Kurata et al., 2002; Ohno, 2006); and a case of primary central nervous system lymphoma (PCNSL, a diffuse large B cell lymphoma confined to the brain) (Schwindt et al., 2006).

Genes Involved and Proteins

Gene name
BCL6 (B-Cell Lymphoma 6)
Location
3q27.3
Protein description
706 amino acids; composed of a NH2-term BTB/POZ domain (amino acids 1-130 (32-99 according to Swiss-Prot) which mediates homodimerization and protein-protein interactions with other corepressors (including HDAC1 and NCOR2/SMRT to constitute a large repressing complex, another transcription repression domain (191-386), PEST sequences (300-417) with a KKYK motif (375-379), and six zinc finger at the C-term (518-541, 546-568, 574-596, 602-624, 630-652, 658-681), responsible for sequence specific DNA binding. Transcription repressor; recognizes the consensus sequence: TTCCT(A/C)GAA (Albagli-Curiel, 2003). Role in germinal centers of lymphoid follicles. BCL6 prevents ATM and TP53 to induce apoptosis in response to DNA rearrangements such as somatic hypermutation and class switch recombination. Therefore essential for normal B cell development.
Gene name
HIST1H4I (histone cluster 1 H4 family member i)
Location
6p22.1
Protein description
Component of the nucleosome. Histones play a major role in DNA repair, replication and transcription.

Result of the Chromosomal Anomaly

Description

Breakpoints in HIST1H4 are located within the single exon to 3 of the terminal palindrome; the breakpoint in BCL6 was located within the major translocation cluster.

Bibliography

Pubmed IDLast YearTitleAuthors
108111032000Molecular anatomy of BCL6 translocations revealed by long-distance polymerase chain reaction-based assays.Akasaka H et al
89880301997A recurring translocation, t(3;6)(q27;p21), in non-Hodgkin's lymphoma results in replacement of the 5' regulatory region of BCL6 with a novel H4 histone gene.Akasaka T et al
125550642003Ambivalent role of BCL6 in cell survival and transformation.Albagli-Curiel O et al
124146512002Characterization of t(3;6)(q27;p21) breakpoints in B-cell non-Hodgkin's lymphoma and construction of the histone H4/BCL6 fusion gene, leading to altered expression of Bcl-6.Kurata M et al
171429542006Pathogenetic and clinical implications of non-immunoglobulin ; BCL6 translocations in B-cell non-Hodgkin's lymphoma.Ohno H et al
168963112006Chromosomal translocations fusing the BCL6 gene to different partner loci are recurrent in primary central nervous system lymphoma and may be associated with aberrant somatic hypermutation or defective class switch recombination.Schwindt H et al

Summary

Fusion gene

HIST1H4I/BCL6 HIST1H4I (6p22.1) BCL6 (3q27.3) M|HIST1H4I/BCL6 HIST1H4I (6p22.1) BCL6 (3q27.3) M t(3;6)(q27;p22)|HIST1H4I/BCL6 HIST1H4I (6p22.1) BCL6 (3q27.3) TIC

Citation

Jean-Loup Huret

t(3;6)(q27;p22) HIST1H4I/BCL6

Atlas Genet Cytogenet Oncol Haematol. 2012-12-01

Online version: http://atlasgeneticsoncology.org/haematological/2009/t(3;6)(q27;p22)-hist1h4i-bcl6

External Links