Vitamin D receptor rs2228570 polymorphism and Parkinson's disease risk in a Chinese population

Epidemiological evidence of the relationship between vitamin D receptor (VDR) rs2228570 (FokI) polymorphism and the susceptibility of Parkinson's disease (PD) is inconsistent, partially due to between-study variations in sample size, age, male/female ratio, and 25-OH vitamin D3 levels. Here, we examined the association between VDR rs2228570 polymorphism and PD risk in a Chinese population. A total of 940 subjects were included in this study, which consisted of 470 patients with sporadic PD (mean age: 62.65 ± 9.34 years) and 470 healthy control subjects (mean age: 62.70 ± 9.42 years). A TaqMan genotyping assay was applied to identify VDR rs2228570 polymorphism. The Hardy-Weinberg Equilibrium (HWE) was calculated for both groups with a Chi-square (χ2) test. The sample power was calculated with Power V3.0. The crude odds ratios (ORs) and 95 % confidence intervals (CIs) for sporadic PD in relation to VDR rs2228570 polymorphism were calculated using a logistic regression analysis. The minor A allele frequency was 0.42 and 0.48 in the control and PD groups, respectively. A allele carriers of rs2228570 were associated with an increased overall risk of PD as well as early-onset PD (EOPD) in the allele and additive genetic models. Stratification analyses showed similar results in male subjects in the allele and additive genetic models, but only in the additive genetic model in female subjects. In conclusion, our study suggests that the VDR rs2228570 A allele is associated with an increased risk of PD in a Chinese population. Further investigations with larger sample sizes with consideration of gene-gene and gene-environment interaction are needed to further elucidate the role of vitamin D receptors in the development of PD.