Association of Vitamin D Receptor-FOKI Gene Polymorphism with Breast Cancer Risk in Iraqi Female Patients

Background: Breast cancer is the most frequent cancer among women worldwide. In Iraq, it is accounting about one third of the registered women cancers. Different studies have shown that the gene polymorphism in vitamin D receptor (VDR-FOKI) was associated with the susceptibility and pathogenesis of breast cancer. Objective: The study aimed to examine the genotyping utility of Vitamin D receptor (VDR-FokI) gene polymorphism as predictor for the occurrence and progression of breast cancer in Iraqi women. Materials and Methods: This case control study was comprised of two groups, the first group consisted of 300 women histopathologically diagnosed with breast cancer either familial or sporadic with age 22-77 year, the second group included 200 healthy women with age 22-78 year, DNA was extracted from blood and genotyping analysis was carried out by PCR-RFLP. Results: The genotypic analysis revealed that allele frequency of TT genotype (29 %), TC genotype (48 %), and CC genotype (23 %) in breast cancer group, while 64.5 %, 30.5 % and 5 % in the control group respectively. The risk of breast cancer was significantly increased with VDR-FOKI SNP by about three and five folds in heterozygous and homozygous of mutant allele genotypes in patients (OR=3.25, 95 % C. I= 2.16-4.89, P=0.0001 and OR= 5.00, 95 % C. I= 2.81-8.92, P= 0.0001 respectively) when compared with the homozygous of normal alleles genotype after adjustment for age and BMI. The C allele frequency increased the risk of disease by three and half times when compared with those of T allele (OR= 3.49, 95 % C. I= 2.6-4.67, P less than 0.0001). Conclusion: We conclude from this study that the gene polymorphism of VDR-FOKI was associated with high risk of development and progression of breast cancer.