The association of vitamin D receptor gene polymorphisms and serum 25-hydroxyvitamin D levels with generalized vitiligo.

BACKGROUND

Vitiligo is an acquired depigmentation autoimmune disorder that has been described as being associated with lower levels of 25-hydroxyvitamin D [25(OH)D]. Genetic variations within the vitamin D receptor (VDR) gene could lead to significant receptor dysfunction, and could further affect the formation of the biologically active 25(OH)D. Therefore, we hypothesized that VDR polymorphisms might be involved in vitiligo by affecting the formation of 25(OH)D.

OBJECTIVES

To evaluate the potential association between VDR polymorphisms and vitiligo susceptibility and the serum levels of 25(OH)D.

METHODS

We performed a hospital-based study of 749 patients with vitiligo and 763 matched controls. We investigated four VDR polymorphisms (FokI, BsmI, ApaI and TaqI) to determine whether they are associated with vitiligo susceptibility in the Chinese population. In addition, the levels of 25(OH)D were measured to evaluate possible associations between the VDR polymorphic variants and clinical and laboratory findings of vitiligo.

RESULTS

A significantly decreased risk of developing vitiligo was found to be associated with the BsmI-B, ApaI-A and TaqI-t alleles. According to the genotype distribution, 25(OH)D concentrations were significantly higher in patients carrying the FokI ff or ApaI AA genotypes compared with those carrying the FF or aa genotypes. Logistic regression analysis also showed a dose-response relationship between decreased risk of vitiligo and increased 25(OH)D levels in ApaI-A variant genotype carriers.

CONCLUSIONS

Our findings suggest that these VDR polymorphisms are associated with 25(OH)D levels and that there exists a genetic predisposition for vitiligo in the Chinese population.