The association between tumor necrosis factor-α-308 G/A polymorphism and risk for vitiligo: a meta-analysis

The contribution of tumor necrosis factor-α (TNF-α)-308 G/A gene polymorphism (rs1800629) to risk for vitiligo is subject to controversy.

The fundamental purpose of the present meta-analysis was to investigate large-scale evidence to determine the overall association between TNF-α-308 G/A polymorphism and susceptibility to vitiligo.

A literature search of the PubMed, EMBASE, Web of Science, and China National Knowledge Infrastructure (CNKI) databases was conducted to identify all studies referring to an association between TNF-α-308 G/A polymorphism and vitiligo published to June 1, 2014. The principal outcome measure for evaluating the strength of the association was the crude odds ratio (OR) along with the corresponding 95% confidence interval (CI). Data were extracted, and statistical analyses were implemented using stata Version 12.0.

Data for a total of 1505 vitiligo cases and 2253 controls from five case-control studies concentrating on the association between TNF-α-308 G/A polymorphism and vitiligo were included in this meta-analysis. Combined analysis revealed there to be no association between this polymorphism and susceptibility to vitiligo in five genetic models under random-effects models. A subgroup analysis by clinical type also demonstrated the absence of any association between TNF-α-308 G/A polymorphism and generalized vitiligo. However, a significant association was detected in the miscellaneous subgroup under the dominant model (fixed-effects model: OR 5.69, 95% CI 4.70-6.88; P = 0.000) and overdominant model (random-effects model: OR 5.24, 95% CI 2.26-12.17; P = 0.000).

This meta-analysis indicates that TNF-α-308 G/A polymorphism is not a genetic risk factor for vitiligo.