Meta-analysis for association of TNFA-308(G > A) SNP with vitiligo susceptibility

Vitiligo is an autoimmune progressive skin depigmenting disease. Tumor necrosis factor alpha (TNF-alpha) is a pro inflammatory cytokine and plays a crucial role in vitiligo development. Since there are conflicting results and consensus is lacking for the association of the TNFA gene-308 G A polymorphism with vitiligo susceptibility; we performed a meta-analysis of all the available studies to investigate the association of TNFA-308 G > A polymorphism with vitiligo risk. 11 studies involving 2199 vitiligo patients and 3083 controls were included in the meta-analysis. The meta-analysis revealed an increased vitiligo risk with AA, GA and AA + GA genotypes and 'A' allele in the overall (p = 0.006, p = 0.003, p = 0.001 & p = 0.003) and Egyptian populations (p = 0.001, p < 0.00001, p < 0.00001 & p = 0.002). Moreover, we found association for GA and AA + GA genotypes in Asian population (p = 0.0009 & p = 0.005) and for 'A' allele in Asian and middle eastern populations (p = 0.04 & p = 0.0002). Interestingly the disease activity based analysis revealed significant association for GA, AA + GA genotypes and 'A' allele with active vitiligo patients in the North American population (p = 0.02). Moreover, we found significant association for GA, AA + GA genotypes and 'A' allele with localized vitiligo in overall (p = 0.02, p = 0.02 & p = 0.04) and Asian (p = 0.004, p = 0.003 & p = 0.01) populations. Overall, our meta-analysis suggests the involvement of susceptible 'A' allele with: i) vitiligo susceptibility in overall population and specifically with Asian, Middle Eastern and Egyptian populations; ii) vitiligo disease activity in North American population and iii) localized vitiligo in overall population and specifically in Asian population.

Automated summary

The TNFA gene-308 G A polymorphism is associated with vitiligo susceptibility, with varied results among different populations. The study also indicates significant associations between gene genotypes and alleles in active vitiligo patients and those with localized vitiligo in different regions.