Abstract: Objective  To evaluate the prevalence and impact of IL7R gene mutations in Tcell acute lymphoblastic leukemia. Methods  Bone marrow samples were collected from 125 patients with TALL,  and 125 cases of specimens were amplified,  cloned and sequenced to analysis the frequencies,  position and the type of gene mutations in IL7R. Some laboratory indexes were used to make a difference between wild type and patients who were detected with IL7R gene mutations. Results  The rate of IL7R mutation was 5.60% (7/125). All seven cases had an inframe insertion or substitution at residues P240S246 of the transmembrane domain of IL7R. Seven mutation sites were identified，including：c.727730 InsAGCCACTGCCAGG DelCTAA, c.724736 InsCCTACGGGAT DelTTACTAACCATCA,  c.732 InsGGGCCCAATATTGTGACGT DelC, c.724736InsCCTACGGGAT DelTTACTAACCATCA, c.732 InsCTAAGGTGC, c.731732 InsGGTTGTCAGAG DelAC,  c.720736 InsAAAACGGT DelTATCTTACTAACCATCA. Conclusion  Seven mutation sites were identified in this study. IL7R mutation might play an important role in the occurrence of TALL.

Key words: leukemia, , lymphoid；leukemia, , Tcell；genes