Association between genetic polymorphism of XRCC7 (G6721T) and risk of acute lymphoblastic leukemia

Abstract

Background: The DNA non-homologous end joining repair gene XRCC7 is one of the most important genes in the DNA double-strand break (DSBs) repair. It is supposed that DNA repair gene malfunction is the main risk factor in various malignancies. The XRCC7 G6721T (rs7003908) polymorphism impact was investigated on the splicing regulation that cause mRNA instability. The goal of the present hospital-based study was to investigate the association between the common genetic polymorphism of XRCC7 G6721T (rs7003908) and risk of acute lymphoblastic leukemia (ALL). This hospital-based case–control study was performed on 99 ALL patients versus 200 healthy children, as the control group, which were frequent matched by age with cases. The polymorphism of XRCC7 was determined using an RFLP-PCR technique. Results: The GT (OR = 1.485, 95% CI 0.765–2.334, P = 0.243) and TT (OR = 1.655, 95% CI 00.875–3.128, P = 0.121) genotypes had no significant effect on the risk of ALL, in comparison with the GG genotype. However, TT genotype (OR = 1.996, 95% CI 1.033–3.858, P = 0.04) after adjusting for the parents’ smoking pattern showed a significant impact. Conclusions: These findings suggest that the TT genotype may increase the ALL susceptibility in children when facing with a tobacco smoke.