Relationship between chromosomal breakpoint and molecular rearrangement of T-cell antigen receptors in adult T-cell leukaemia.

The relationship between chromosome breakpoints associated with T-cell antigen receptor (TCR) genes and TCR-alpha/beta/tau/delta rearrangements of peripheral leukaemic cells in 8 Japanese patients with the acute type of adult T-cell leukaemia (ATL) was examined. Break of the 14q11 region with the assigned locus of TCR-alpha/delta was revealed in 6 patients, interstitial deletion of the 7q32-36 region with assigned locus of TCR-beta in 1 patient, and break of the 7p15 region with assigned locus of TCR-tau in 2 patients. Molecular analysis revealed TCR-alpha rearrangement in 7 patients, TCR-beta rearrangement in all patients, and TCR-tau rearrangement in 5 patients. TCR-delta was deleted in all patients. These findings indicate a close relationship between 14q11 anomaly and TCR-alpha rearrangement, which may play an important role in the leukaemogenesis of ATL.