Vitamin D Receptor BsmI Gene Polymorphisms and Gestational Diabetes Mellitus: A Saudi Study

Background: Both vitamin D deficiency and Gestational diabetes (GDM) are common among Saudis. The vitamin D receptor (VDR) gene is a candidate gene for susceptibility to several diseases. Studies on association between VDR polymorphisms and risk of GDM in Saudi populations are yet inconclusive. Objective: to evaluate the association between Vitamin D receptor gene polymorphisms and genetic susceptibility to gestational diabetes (GDM) in pregnant Saudis. Subjects & Methods: thirty pregnant Saudi women with diabetes (17 GDM and 13 type 2 diabetes (T2DM) with past history of GDM) were compared to 14 pregnant women with normal glucose tolerance. Patients and controls were recruited at their third trimester from Taibah University medical unit from January to July 2010. Genomic DNA was extracted and the genotyping related to vitamin D receptor BsmI gene single – nucleotide polymorphisms was carried out by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) analysis. Results: The gene frequency, allele frequency and carriage rate of the VDR polymorphism BsmI did not differ between patients and controls with no significant association with any clinical parameters. The 25 hydroxyl Vitamin D level but not the gene frequency was a significant predictor of history of abortion among diabetics (OR=- 0.29, 95% CI -0.081-0.0, p=0.047). Conclusions: Vitamin D receptor BsmI gene polymorphisms is not associated with gestational diabetes among Saudis. Further studies of other Vitamin D receptor gene polymorphism in combination are required