Chromosomal translocation involving the immunoglobulin kappa-chain and heavy-chain loci in a child with chronic lymphocytic leukemia.

Chronic lymphocytic leukemia is usually a monoclonal B-cell neoplasm that occurs almost exclusively in middle-aged and elderly adults. We observed a rapidly progressive case of the disease in a 10-year-old girl. The leukemic cells bore surface IgM and IgD immunoglobulins of the kappa-light-chain type. Karyotyping of the abnormal cells revealed an unusual translocation [t(2;14) (p13;q32)], with break points at or near the kappa-light-chain and heavy-chain gene loci. Translocations involving the immunoglobulin gene loci may be important in the pathogenesis of some cases of chronic lymphocytic leukemia, as they appear to be in Burkitt's lymphoma.