Vitamin D receptor Gene polymorphisms and their relation to Bone Mineral Density in Egyptian osteoporotic patients

Objective: VDR gene polymorphisms and their functional significance and potential effects on disease susceptibility have been investigated. The present study was aimed to identify the genetic polymorphism of Vitamin D receptor in osteoporotic patients. Methods: Peripheral blood samples were obtained from 25 osteoporotic females and 25 healthy controls. All subjects were diagnosed by bone mineral density measurement. DNA was extracted and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was performed to identify VDR genes (FOKI and BSMI) polymorphism. Results: The frequencies of BB, Bb and bb genotypes (BSMI polymorphism) in (Osteoporotic patients) were 52%, 32% and 16% , respectively.While their frequency in controls was 12%, 24% and 64%, respectively. The BB genotype was higher in patients than in controls (P = 0.0000) while the bb genotype was significantly higher in controls than in patients. Regarding the FOKI polymorphism the frequencies of FF, Ff and ff genotypes in (Osteoporotic patients) were 68%, 12% and 20%, while their frequency in controls was 84%, 16% and 0%, respectively. Subjects carrying either B+ve or f+ve genotype were more risky to develop osteoporosis,( OR 9.33, 1.43) respectively. Conclusions: The BB genotype was higher in all patients than controls and the bb genotype is a protective genotype. The FF genotype was predominant among controls and ff genotype was associated with osteoporosis. Currently, however, the mechanisms by which VDR alleles regulate BMD remain poorly understood.