Genetic variation in DNA repair gene XRCC7 (G6721T) and susceptibility to breast cancer

Abstract The human XRCC7 is a DNA double-strand break (DSBs) repair gene, involved in non-homologous end joining (NHEJ). It is speculated that DNA DSBs repair have an important role during development of breast cancer. The human XRCC7 is a NHEJ DSBs repair gene. Genetic variation G6721T of XRCC7 (rs7003908) is located in the intron 8 of the gene. This polymorphism may regulate splicing and cause mRNA instability. In the present study, we specifically investigated whether common G6721T genetic variant of XRCC7 was associated with an altered risk of breast cancer. The present study included 362 females with breast cancer. Age frequency-matched controls (362 persons) were randomly selected from the healthy female blood donors, according to the age distribution of the cases. Using RFLP-PCR based method, the polymorphism of XRCC7 was determined. The TG (OR = 1.20, 95% CI: 0.83–1.74, P  = 0.320) and TT (OR = 1.01, 95% CI: 0.67–1.53, P  = 0.933) genotypes had no significant effect on risk of breast cancer, in comparison with the GG genotype. Our present findings indicate that the TT and TG genotypes were not associated with an altered breast cancer risk.