T cell receptor α-chain gene rearrangements in B-precursor leukemia are in contrast to the findings in T cell acute lymphoblastic leukemia. Comparative study of T cell receptor gene rearrangement in childhood leukemia

Abstract

We have analyzed T cell receptor α-chain gene configuration using three genomic joining (J) region probes in 64 children with acute lymphoblastic leukemia (ALL). 11 out of 18 T-ALLs were T3 positive; α-chain gene rearrangements were demonstrated in only two of 18, indicating that the majority of T-ALLs would have rearrangements involving Jα segments located upstream of these probes. In contrast, 15 out of 46 B-precursor ALLs showed rearrangements of the α-chain gene and Jα segments located ~ 20-30 kb upstream of the constant region were involved in 13 of these patients. Nine of 15 B-precursor ALLs with rearranged α-chain genes had rearrangements of both γ- and β-chain genes, whereas the remaining six had no rearrangements of γ- and β-chain genes. These findings indicated that α-chain gene rearrangement is not specific for T lineage cells and γ- and/or β-chain gene rearrangement does not appear essential for α-chain gene rearrangement, at least in B-precursor leukemic cells.