Vitamin D receptor (FokI, BsmI and TaqI) gene polymorphisms and type 2 diabetes mellitus: a North Indian study.

BACKGROUND The vitamin D receptor (VDR) gene is a candidate gene for susceptibility to several diseases. Studies on association between VDR polymorphisms and risk of type 2 diabetes (T2DM) in different ethnic populations are yet inconclusive. AIMS This study was conducted to evaluate association between VDR polymorphisms and genetic susceptibility to T2DM in the north Indian population. SETTINGS AND DESIGN One hundred clinically diagnosed T2DM patients and 160 healthy controls from the north Indian population were recruited for genetic association study. MATERIALS AND METHODS Genomic DNA was extracted from blood and genotyped for the single nucleotide polymorphism SNPs of FokI (T/C) [rs2228570], BsmI (A/G) [rs1544410] and TaqI (C/T) [rs731236] by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) analysis. STATISTICAL ANALYSIS USED Genotype distribution and allelic frequencies were compared between patients and controls. Mean values and odds ratios (ORs) with 95% confidence interval (CI) were calculated using SPSS software (version 15.0). RESULTS The genotype distribution, allele and haplotype frequencies of VDR polymorphism did not differ significantly between patients and controls. Mean age and waist-hip ratio of patients were found to be associated with VDR polymorphism. Combination studies showed FFBbtt increased the risk of T2DM in north Indians. CONCLUSIONS Our data suggest that VDR gene polymorphism in combination of genotypes is associated with the risk of T2DM and thus requires further studies as a probable genetic risk marker for T2DM.