An additional breakpoint region in the BCL-1 locus associated with the t(11;14)(q13;q32) translocation of B-lymphocytic malignancy

Abstract

The t(11;14)(q13;q32) translocation is associated with human B-lymphocytic malignancy. This translocation divides the IgH locus on chromosome 14q32 and may activate a postulated proto-oncogene, bcl-1, located on chromosome 11q13. Two samples of chronic lymphocytic leukemia with the t(11;14)(q32;q13) translocation were studied. The break in one sample was shown to join Jh sequences with the previously described bcl-1 major translocation cluster. DNA blots of the second sample suggested that Jh sequences were joined to a different breakpoint region on chromosome 11. This translocation was cloned and found to link the human Jh3 region and a new breakpoint region 63 kb telomeric of the major translocation cluster. This translocation occurred in part as the result of an aberrant D-J recombination. Recurrent translocations involving the bcl-1 locus emphasize its importance for human B-lymphocytic malignancy. The definition of a new breakpoint region may aid the identification of the postulated bcl-1 gene.