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-α/β/τ/δ rearrangements of peripheral leukaemic cells in 8 Japanese patients with the acute type of adult T-cell leukaemia (ATL) was examined. Break of the 14qll region with the assigned locus of TCR-α/δ was revealed in 6 patients, interstitial deletion of the 7q32-36 region with assigned locus of TCR-β in 1 patient, and break of the 7pl5 region with assigned locus of TCR-τ in 2 patients. Molecular analysis revealed TCR-α rearrangement in 7 patients, TCR-β rearrangement in all patients, and TCR-τ rearrangement in 5 patients. TCR-δ was deleted in all patients. These findings indicate a close relationship between 14qll anomaly and TCR-α rearrangement, which may play an important role in the leukaemogenesis of ATL.