Chromosome abnormalities at 11q13 in B cell tumours

B cell tumours have frequently been found to possess translocations involving the long arm of chromosome 14 at band q32. These include a translocation t(11;14) (q13;32). We describe the molecular cloning of the t(11;14) junction from a B-cell prolymphocytic leukaemia which involves a breakage within the immunoglobulin heavy chain J(H)4 joining segment, and sequences from chromosome 11q13 which show homology to an L1-repeat element. The 11q13 breakpoint is different from previously cloned examples, but seems to occur within about 1 Kb of these. An additional breakpoint was detected in a myeloma tumour, about 36 Kb from the previously identified locus. Thus, although the translocation t(11;14) is relatively rare in B cell tumours, a number of different types of tumour have now been shown to carry abnormalities within this region of chromosome 11q13. These observations strengthen the correlative argument that this locus may be important for B cell tumour pathogenesis, if involved in a chromosomal translocation.