FOXP3 gene genetic variants linked with vitiligo
medwireNews: Three variants in the forkhead box P3 (FOXP3) gene are associated with increased risk for vitiligo in the Han Chinese population, show study findings.
"Previous studies found that CD4+CD25+ regulatory T cell (Treg) dysfunction was involved in the pathogenesis of vitiligo and that gene polymorphisms in FOXP3 - a master regulator of
Treg development and function - were associated with susceptibility to some autoimmune disorders," explain the authors in the British Journal of Dermatology.
To test whether functional FOXP3 variants influence risk for vitiligo, Chunying Li (Fourth Military Medical University, Shaanxi, China) and colleagues genotyped 682 people with vitiligo and 682 age- and gender-matched controls for three single nucleotide polymorphisms (SNPs) in the FOXP3 gene - rs2232365, rs3761548, and rs5902434.
People who were homozygous for the G allele of rs2232365 had a significant 68% increased risk for vitiligo compared with those homozygous for the A allele. Similarly, those homozygous for the A allele of rs3761548 had an 82% increased risk for vitiligo compared with C allele homozygotes. No links between rs5902434 genotype and vitiligo risk were seen, however.
When a combined analysis of all three SNPs was carried out, the team found that people who carried 2-6 risk alleles were 34% more likely to have vitiligo than people with no risk alleles.
Notably, the effects of the combined genotype for the three SNPs were more pronounced in certain groups, namely, men, those over the age of 20 years, those with active or segmental vitiligo, and those with other autoimmune disorders.
"We have provided evidence that FOXP3 polymorphisms have a significant effect on the risk for developing vitiligo in the Han Chinese population; our results thus contribute to a better understanding of the interaction between vitiligo and FOXP3-mediated regulation of Treg activity," say Li et al.
"These regulatory FOXP3 polymorphisms may be developed as novel therapeutic targets for vitiligo in the future," the researchers suggest, although they concede that "large prospective studies involving multiple centres and larger populations may be required to confirm these findings," before any such therapies can be developed.
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By Helen Albert, Senior medwireNews Reporter