The association of functional polymorphisms in the aryl hydrocarbon receptor (AHR) gene with the risk of vitiligo in Han Chinese populations.

BACKGROUND

Vitiligo is an acquired depigmentation disorder resulting from selective destruction of melanocytes. The aryl hydrocarbon receptor (AHR) is vital to the regulation of melanogenesis and melanocyte proliferation and differentiation through modulating the expressions of melanogenesis-related genes. AHR mutations may negatively affect AHR proteins and its target genes. Therefore, we hypothesized that AHR polymorphisms might be involved in vitiligo by impacting the transcriptional activities of related genes as mentioned above.

OBJECTIVES

To evaluate the potential association between AHR polymorphisms and vitiligo susceptibility.

METHODS

We performed a hospital-based, case-control study of 1000 patients with vitiligo and 1000 vitiligo-free but age- and gender-matched controls. Two single nucleotide polymorphisms of the AHR gene (rs10249788 and rs2066853) were selected and genotyped using a polymerase chain reaction-restriction fragment length polymorphism method.

RESULTS

A statistically significantly decreased risk of vitiligo was found to be associated with the TT and CT genotypes of rs10249788 [odds ratio (OR) 0·59, 95% confidence interval (CI) 0·38-0·93; P = 0·028 and OR 0·82, 95% CI 0·68-0·98; P = 0·032, respectively] as well as among subgroups: male, active, nonsegmental vitiligo, and onset age ≤ 20 years. Moreover, subjects with the combined (CT + TT)/GG genotype or T/G haplotype (rs10249788/rs2066853) showed a decreased risk for vitiligo (OR 0·57, 95% CI 0·37-0·87, P = 0·009 and OR 0·78, 95% CI 0·64-0·96, P = 0·033, respectively).

CONCLUSIONS

These results suggest that the T allele of rs10249788 located in the promoter of the AHR gene is associated with a protective effect on vitiligo in Han Chinese populations.