Fusion of an immunoglobulin variable gene and a T cell receptor constant gene in the chromosome 14 inversion associated with T cell tumors.

An inversion of chromosome 14, inv(14)(q11,q32), is frequently observed in human T cell tumors; the cytogenetic breakpoints are of interest because the T cell receptor alpha-chain and immunoglobulin heavy chain genes reside on chromosome bands 14q11 and 14q32, respectively. We have investigated the structure of the alpha-chain genes in a T cell line harboring the chromosome 14 inversion. On the normal chromosome 14, a V alpha segment has rearranged nonproductively with a J alpha segment. In contrast, the inverted chromosome features an unprecedented rearrangement in which an immunoglobulin heavy chain variable gene segment (VH) on chromosome band 14q32 has joined with a J alpha segment from band 14q11. The VH-J alpha C alpha rearrangement is productive at the genomic level and therefore may encode a hybrid immunoglobulin/T cell receptor polypeptide.