BsmI but not FokI polymorphism of VDR gene is contributed in breast cancer

There is growing evidence of a malignancy-protective role for vitamin D in breast cancer. The effects of vitamin D are mediated via the vitamin D receptor (VDR) which is encoded by VDR gene. Several SNPs on VDR gene has attracted research interest, although the magnitude of the impact of VDR allelic variations on breast cancer has been controversial. In the present study, we focused on the distribution of VDR FokI and BsmI polymorphisms in Iranian breast cancer patients. A case-control study was conducted on 296 samples including 140 breast cancer patients and 156 age matched control women. Restriction fragment length polymorphism (RFLP) analysis was performed for BsmI and FokI genotyping. Randomly selected PCR products were subjected to sequencing to verify the RFLP results. A significantly increased risk of breast cancer was observed with BsmI bb or even Bb genotype (OR 2.39, CI 1.17-4.85 and OR 2.28, CI 1.16-4.47, respectively). Nevertheless, statistically significant association between FokI genotypes and breast cancer risk was not observed. This study lends support for an increased risk of breast cancer associated with the VDR BsmI polymorphism.