Analysis of the association between polymorphisms in the vitamin D receptor (VDR) gene and dental caries in a Chinese population

Environmental influences on the development and progression of dental caries are well known; however, there is little evidence of a genetic component imparting susceptibility to dental caries. The aim of this study was to investigate the relationship between a single nucleotide polymorphism in the vitamin D receptor TaqI locus and dental caries susceptibility in a Chinese population. This case-control study was conducted with a case group (264 patients with dental caries from northwestern China) and a control group (219 individuals without dental caries or systemic disease from the same area). DNA was extracted from the peripheral venous blood of the study participants; the distribution of TaqI locus genotypes and allele frequencies was determined via polymerase chain reaction-restriction fragment length polymorphism. The data obtained were statistically analyzed using the Hardy-Weinberg equilibrium and Chi-square test. The frequency of the Tt genotype in the case group (14.0%) was significantly higher than that in the control group (4.3%), as determined using the genotype TT as the reference. The risk of dental caries was increased 3.8-fold in individuals with the heterozygous Tt genotype compared to that in the individuals with the TT genotype. The proportion of the 't' allele in the case group (7.0%) and the control group (2.1%) was observed to be significantly different [P = 0.0003; OR = 3.592, confidence interval 95% (1.790-7.208)]. Our results therefore suggested that the allele 't' might be a genetic factor determining dental caries susceptibility in individuals from the northwest of China.