# BCL2 rearrangement, t(14;18)

Source: https://onco.cc/biomarkers/bcl2-rearrangement/  
OnCo record `bcl2-rearrangement` (Biomarker). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A swap of DNA that puts the survival gene BCL2 next to an antibody gene, so the cell makes far too much of a protein that stops it dying. It is the founding event of most follicular lymphomas and it happens in the bone marrow, often years before anything is wrong.

## Summary

The t(14;18)(q32;q21) translocation joins BCL2 on chromosome 18 to the immunoglobulin heavy-chain locus on chromosome 14, so the anti-apoptotic protein is driven by the enhancer that should be driving antibody production. Sequencing the junctions showed that the breakpoints sit close to the 5' end of the JH segment, carry extraneous N-region nucleotides and lie beside signal-like sequences on chromosome 18, which identifies the translocation as a mistake by the VDJ recombinase at the pre-B-cell stage rather than a late event in a lymphoma (Tsujimoto 1985).

It is present in the large majority of follicular lymphomas and in 13.5% of 442 unselected diffuse large B-cell lymphomas in the RICOVER cohort, where BCL2 protein was expressed in 79.6% of tumours, far more often than the gene was rearranged (Horn 2013). A cell carrying the translocation can be found in the blood of healthy people, so the result on its own is not a diagnosis.

## Fields

- Kind: Biomarker
- Last checked: 2026-09-30
- Also known as: t(14;18); IGH::BCL2; BCL2 translocation; BCL2 break-apart FISH; bcl-2 rearrangement
- Tags: biomarker; lymphoma

## Sources

- Tsujimoto et al., Science 1985: the t(14;18) translocation results from a mistake in VDJ joining: https://doi.org/10.1126/science.3929382
- Horn et al., Blood 2013: MYC, BCL2 and BCL6 rearrangement and expression in 442 RICOVER patients: https://doi.org/10.1182/blood-2012-06-435842

## Connected records

- biomarkers: [BCL2 G101V and the other venetoclax binding-site mutations](https://onco.cc/biomarkers/bcl2-g101v/), [Double expressor: MYC and BCL2 protein together by immunohistochemistry](https://onco.cc/biomarkers/myc-bcl2-double-expressor/), [Double-hit and triple-hit: MYC with BCL2 and BCL6 rearrangement](https://onco.cc/biomarkers/double-hit-rearrangement/), [EZH2 gain-of-function mutation (Tyr646, originally Tyr641)](https://onco.cc/biomarkers/ezh2-y646-mutation/)
- cancers: [Diffuse large B-cell lymphoma](https://onco.cc/cancers/dlbcl/), [Follicular lymphoma](https://onco.cc/cancers/follicular-lymphoma/), [Non-Hodgkin lymphoma (all types)](https://onco.cc/cancers/non-hodgkin-lymphoma/)
- technologies: [Cytogenetics and FISH](https://onco.cc/technologies/cytogenetics-fish/), [Histopathology & immunohistochemistry](https://onco.cc/technologies/histopathology-ihc/)
- targets: [BCL-2](https://onco.cc/targets/bcl2/)
- drugs: [Venetoclax](https://onco.cc/drugs/venetoclax/)
- pathways: [Intrinsic apoptosis (BCL-2 family)](https://onco.cc/pathways/apoptosis-bcl2/), [The germinal centre reaction](https://onco.cc/pathways/germinal-centre-reaction/)
- terms: [Cytogenetics and karyotype](https://onco.cc/terms/cytogenetics/), [FISH / ISH (in situ hybridisation)](https://onco.cc/terms/fish/), [The germinal centre: why lymphoma starts where antibodies are made](https://onco.cc/terms/lymphoma-bio-germinal-centre/)

---
JSON: https://onco.cc/api/v1/entities/bcl2-rearrangement.json