Concomitant rearrangements of T-cell β- and γ-chain genes in childhood T-lineage leukemia/lymphoma

Abstract

Similar to the immunoglobulin (Ig) gene rearrangements in B-lineage cells, identification of T-cell receptor (TCR) gene rearrangements is a novel clonal marker and necessary to establish a T-cell lineage. The function of T-cell γ-chain (T γ) gene is still unknown, but because of its shared properties with T-cell α-chain (T α) and T β genes, we analysed T γ gene organization in 10 patients with T-lineage leukemia/lymphoma as well as in non-T-lineage leukemias. All 10 cases of T-lineage leukemia/lymphoma, whose phenotypes were different, demonstrated T γ gene rearrangements as well as T β gene rearrangements. In contrast, among the non-T-lineage leukemias, the emergence of T β and/or T γ gene rearrangements was varied. Based on these findings, concomitant rearrangements of T β and T γ genes are characteristic in childhood T-lineage leukemia/lymphoma regardless of their phenotypic differences. Furthermore, no obvious developmental hierarchy was observed between T β and T γ gene arrangements in these leukemia/lymphoma cells.