A novel alteration in the structure of an activated c-myc gene in a variant t(2;8) Burkitt lymphoma

Abstract

We have characterized a variant Burkitt lymphoma in which translocation joins the immunoglobulin kappa locus on chromosome 2 to the c-myc gene on chromosome 8. This Burkitt lymphoma is especially interesting because, in contrast to the more common lymphomas that carry 8;14 translocations, it carries a translocation that involves a light chain locus and occurs 3' to and at least 20 kb downstream of the c-myc gene. Furthermore, the c-myc gene from the translocated chromosome is abnormally expressed in that there is a characteristic shift in c-myc promoter utilization and an increase in c-myc transcript. These disturbances could be explained by novel structural alterations that occur in the c-myc gene and include a duplication of a 2.5 kb segment of DNA containing the two c-myc promoters and their untranslated leader exons. Interestingly, these alterations arise at a considerable distance from the translocation breakpoint.