The functional BRCA1 rs799917 genetic polymorphism is associated with gastric cancer risk in a Chinese Han population

BRCA1 is a crucial tumor suppressor which plays an essential role in maintaining genomic stability and integrity. Accumulated evidences demonstrated that there is frequent chromosome loss of BRCA1 or significant BRCA1 down-regulation via hypermethylation of its promoter in human gastric cancer specimens, highlighting the tumor-suppressing function of BRCA1 in gastric carcinogenesis. There is an rs799917 T>C single nucleotide polymorphism (SNP) located in the BRCA1 coding sequence (CDS). This SNP can disturb the interaction between BRCA1 mRNA and miR-638 and result in significantly decreased BRCA1 expression among carriers of rs799917C allele. In this study, we investigated the association between rs799917 and gastric cancer risk in a Chinese Han population using a case–control design. A total of 660 gastric cancer patients and 800 controls were enrolled and genotyped. Odds ratios (ORs) and 95 % confidence intervals (CIs) were calculated by logistic regression. We found that individuals with the rs799917 CT genotype was significantly associated with gastric cancer risk (OR = 1.81, 95 % CI = 1.28–2.56; P = 0.001). Individuals having the rs799917 CC genotype had an OR of 1.40 (95 % CI = 1.17–1.68; P = 2.2 × 10−4) for developing gastric cancer, compared with individual having the rs799917 TT genotype. However, stratified analyses did not find any evident gene–covariates interaction. Our results for the first time indicate that the functional BRCA1 rs799917 polymorphism contributes to gastric cancer susceptibility.