Abstract
We describe two types of IGH::BCL2 breakpoints involving the 5′ region of BCL2 (5′ BCL2). One was ins(14;18)(q32;q21q21) observed in 2 follicular lymphoma (FL) cases, in which IGH was cleaved at 3’ of IGHD and 5’ of IGHJ and BCL2 was cleaved at 5’ BCL2 and downstream regions, and a 281- or 201-kilobase pair fragment containing the BCL2 protein-coding sequences was invertedly inserted into IGH. In another type observed in 2 FL and 2 chronic lymphocytic leukemia (CLL) cases, breakage and reunion occurred within the switch region associated with IGHM (Sµ) and 5′ BCL2, creating IGH Sµ::5′ BCL2 fusion sequences on der(18)t(14;18)(q32;q21). The former is considered to be mediated by VDJ-recombination, while the latter by the class switch recombination process. There were no particular features in FL or CLL cases with IGH::5′ BCL2 breakpoints compared with those with t(14;18)(q32;q21)/IGH::BCL2 involving the 3′ breakpoint cluster regions.
Ethical approval
The present study was performed according to the regulations of the Institutional Review Board (Approval No. 1787).
Disclosure statement
No potential conflict of interest was reported by the author(s).
Correction Statement
This article has been corrected with minor changes. These changes do not impact the academic content of the article.