Analysis of vitamin D receptor gene polymorphisms in vitiligo.

BACKGROUND

Vitiligo is a progressive depigmenting disorder characterized by the loss of functional melanocytes from the epidermis. The etiopathogenesis of vitiligo is still unclear. Vitamin D has both stimulatory and protective effects on melanocytes and acts through its nuclear vitamin D receptor (VDR) on target cells.

AIM: The aim of this study was to investigate the association between VDR gene polymorphisms and susceptibility to vitiligo.

METHODS

98 patients with vitiligo and 216 age- and sex-matched controls recruited from dermatology outpatients attending the same department were included in the study. Genomic DNA was extracted from peripheral blood leukocytes using a DNA isolation kit. The VDR polymorphisms of BsmI, ApaI, TaqI, FokI and Cdx2 were investigated by rapid capillary PCR with melting curve analysis. Differences in genotype distributions and allele frequencies in vitiligo cases versus controls were compared for statistical significance using χ(2) test.

RESULTS

Subjects with TaqI polymorphism had a 2.23-fold increased risk of developing vitiligo. Furthermore, a haplotype analysis showed that BsmI/ApaI/TaqI/FokI/Cdx2 GCCCG was significantly overrepresented in the vitiligo patients in comparison with controls (p = 0.031).

CONCLUSION

This study showed that VDR TaqI gene polymorphism and the haplotype BsmI/ApaI/ TaqI/FokI/Cdx2 GCCCG may be considered as novel risk factors in vitiligo.