New genetics of Burkitt's lymphoma and other non-Hodgkin's lymphomas

Recent progress in cytogenetics and molecular genetics allows striking new insight into Burkitt's lymphoma. In this B cell tumor, the oncogene c-myc located on the long arm of chromosome 8 translocates to one of three locations: adjacent to the immunoglobulin heavy chain gene on chromosome 14, adjacent to the gene for the kappa light chain of immunoglobulin on chromosome 2, or adjacent to the gene for the lambda light chain on chromosome 22. Nucleotide sequence analysis indicates that the translocated c-myc is usually upstream of an immunoglobulin constant region gene, although the exact position varies. In its new location, the oncogene is actively transcribed and may have escaped its normal control mechanisms. It can be no coincidence that this B cell lymphoma is intimately associated with a misadventure in the genetic underpinnings of the major event in B cell differentiation, the assembling of a functional immunoglobulin molecule. Similar genetic catastrophes probably account for the more common B cell lymphomas and could provide the basis of a coherent lymphoma classification.