t(14;19)(q32;q13) breakpoints telomeric to <i>BCL3</i> on 19q13.32 in B-cell lymphomas other than chronic lymphocytic leukemia and long-range structures of der(19)t(14;19) based on optical genome mapping

t(14;19)(q32;q13) is found in a fraction of chronic lymphocytic leukemia (CLL) patients and creates the <i>IGH</i>::<i>BCL3</i> fusion gene, but this translocation has been observed in B-cell lymphomas other than CLL (non-CLL BLs). Ultra-high molecular weight DNA from liquid nitrogen-frozen leukemia cells of one CLL patient and OCT compound-embedded cryopreserved biopsies from two non-CLL BL patients, all of whom carried cytogenetic t(14;19), were subjected to optical genome mapping. In the CLL patient, t(14;19) resulted in fusion between <i>IGHA1</i> and <i>BCL3</i>, whereas in the non-CLL BL patients, breakpoints on 19q13.32 involved <i>NECTIN2</i> and <i>BCAM</i> as the <i>IGH</i> partners, both of which were located telomeric to <i>BCL3</i>. On der(19)t(14;19), chromosome 19 sequences centromeric to the breakpoints were fused to the germline <i>IGHV</i>s, or <i>IGHV-D-J</i> rearrangement sequences followed by the 5' Eµ enhancer and <i>IGHM</i>/<i>IGHD</i> constant genes. In the non-CLL BL patients, <i>BCL3</i> was retained on der(19)t(14;19) and potentially affected by the translocated <i>IGH</i>.