t(1;3)(q25;q27) GAS5/BCL6

2012-11-01   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

Epidemiology

Two cases to date: two male patients (one was aged 49-years) with diffuse large B-cell lymphoma (Chenevix-Trench et al., 1988; Nakamura et al., 2008).

Prognosis

The patient reported in Nakamura et al., 2008 was treated with chemotherapy, but died of progressive disease 7 months after the diagnosis.

Genes Involved and Proteins

Note
The genes involved in the translocation were, indeed, described in the most recent report.
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
GAS5 (growth arrest-specific 5 (non-protein coding))
Location
1q25.1
Protein description
GAS5 exons do not encode a polypeptide product (small nucleolar RNA (snoRNA) sequence) of the 5TOP gene family; role in the regulation of cell growth; provokes growth arrest; overexpression of GAS5 transcripts is reported to induce apoptosis.

Result of the Chromosomal Anomaly

Description

The 5-terminal oligopyrimidine sequence of GAS5 was fused to the whole coding sequence of BCL6: GAS5 exon 3 was fused to BCL6 exon 2 (BCL6 exon 1 is noncoding).

Highly cited references

Pubmed IDYearTitleCitations
184068792008The GAS5 (growth arrest-specific transcript 5) gene fuses to BCL6 as a result of t(1;3)(q25;q27) in a patient with B-cell lymphoma.41

Bibliography

Pubmed IDLast YearTitleAuthors
125550642003Ambivalent role of BCL6 in cell survival and transformation.Albagli-Curiel O et al
32592791988Chromosome analysis of 30 cases of non-Hodgkin's lymphoma.Chenevix-Trench G et al
184068792008The GAS5 (growth arrest-specific transcript 5) gene fuses to BCL6 as a result of t(1;3)(q25;q27) in a patient with B-cell lymphoma.Nakamura Y et al

Summary

Fusion gene

GAS5/BCL6 GAS5 (1q25.1) BCL6 (3q27.3) M|GAS5/BCL6 GAS5 (1q25.1) BCL6 (3q27.3) M t(1;3)(q25;q27)

Citation

Jean-Loup Huret

t(1;3)(q25;q27) GAS5/BCL6

Atlas Genet Cytogenet Oncol Haematol. 2012-11-01

Online version: http://atlasgeneticsoncology.org/haematological/1625/t(1;3)(q25;q27)

External Links