Further evidence for the contribution of the BRCA1-interacting protein-terminal helicase 1 (BRIP1) gene in breast cancer susceptibility.

BRCA1-interacting protein C-terminal helicase 1 (BRIP1) is a DNA helicase that influences the DNA repair ability and tumor suppressor function of BRCA1. Truncating BRIP1 mutations have been described as cancer susceptibility alleles. To evaluate BRIP1 polymorphisms as risk factors for breast cancer, we performed a detailed analysis of possible single nucleotide polymorphisms (rs2048718, rs4988344, rs8077088, rs6504074, rs4986764, rs4986763, rs11079454, rs7213430, rs34289250, rs4988345, and rs12937080) using the MassARRAY system. A total of 319 patients with breast cancer and 306 healthy control females from the Chinese Han population enrolled in the study. A weak association was found between the rs4986764 allele (exon 18) and breast cancer. The frequency of the rs4986764 C allele was significantly higher in breast cancer patients than in healthy controls [χ(2) = 4.089, P = 0.043, odds ratio (OR) = 0.781, 95% confidence interval (CI) = 0.614-0.992]. Additionally, our study is the first to identify a significant association between rs7213430 and breast cancer. Compared to healthy controls, patients with breast cancer had a higher frequency of the rs7213430 A allele (χ(2) = 8.865, P = 0.003, OR = 0.700, 95%CI = 0.553-0.886). Furthermore, linkage disequilibrium was observed in two blocks (D' > 0.9). While significantly more T-A-C haplotypes (P = 0.001, block 1) were found in breast cancer patients, the frequency of T-T haplotypes (P = 0.008, block 2) was significantly higher in healthy controls. The possible association among rs4986764, rs7213430, and breast cancer risk merits further validation in an independent case-control study.