Association of low penetrance vitamin D receptor Tru9I (rs757343) gene polymorphism with risk of premenopausal breast cancer

OBJECTIVE: The aim of this study was to determine whether a novel polymorphism (Tru9I) in the low penetrance vitamin D receptor (VDR) gene is associated with risk of premenopausal breast cancer (BC). METHODS: This case-control study included 228 patients with BC and 503 healthy women living in Pakistan who were analyzed for the VDR Tru9I (rs757343) single nucleotide polymorphism. BC cases were histopathologically confirmed, and all healthy controls were age-matched with patients (age range, 20–45 years). DNA was extracted, and the polymerase chain reaction and restriction fragment length polymorphism assays were performed. RESULTS: The VDR Tru9I polymorphism was not significantly associated with premenopausal BC. However, the risk of BC was associated with the ‘uu’ genotype (odds ratio [OR], 1.141; 95% confidence interval [95% CI], 0.206–6.317). Further, mutant Tru9I was significantly associated with Grade IV carcinoma (OR, 5.36; 95% CI, 1.181–24.338). CONCLUSION: The VDR Tru9I ‘uu’ genotype may increase the risk of premenopausal BC.