Association of Polymorphisms in the VDR, CYP17 and SRD5A2 Genes and Prostate Cancer Among Lebanese Men

Aims: The goal of this study was to investigate possible associations of some single nucleotide polymorphisms (SNPs) in the VDR gene (the FokI, BsmI, ApaI and TaqαI loci), and the CYP17 gene (the MspA1I locus), and variable numbers of TA repeats in the SRD5A2 gene, with prostate cancer (PCa), among Lebanese men. Materials and Methods: Blood DNA samples of 50 subjects with confirmed PCa and 79 age-qualified controls were subjected to PCR or PCR-RFLP analyses, and the risk-bearing and protective alleles were identified. The odds ratio (OR) of having a genotype and the relative risk (RR) of developing PCa were calculated. In addition, the distribution of homozygosis in the risk-bearing and protective alleles were compared between the control and the PCa groups. Results: The A and B alleles of the VDR ApaI and BsmI loci and the 0 TA repeat allele of the SRD5A2 gene were found to be associated with increased risk of PCa (p = 0.022, 0.029 and 0.013, respectively). A higher percentage of the subjects with PCa compared to the controls was homozygous for two or more of the risk-bearing alleles (46% for PCa, 27% for controls, p = 0.023). In contrast, a higher percentage of the controls compared to the PCa group was homozygous in two or more of the protective alleles (71% for controls, 38% for PCa group, p = 0.001). Conclusions: To the best of our knowledge, this is the first genetic study demonstrating any association of polymorphisms of the VDR and SDR5A2 genes with an increased risk of PCa among Lebanese men. Our study also indicated that the overall polymorphism profile of all genes involved in prostrate physiology is likely to be a better indicator for PCa risk than polymorphisms in individual genes.