Genetic Polymorphisms of Glutathione S-Transferase and Risk of Vitiligo in the Chinese Population

Vitiligo is a common acquired depigmenting disorder characterized by white areas on the skin. Oxidative stress is a major pathogenesis hypothesis of vitiligo. Glutathione S-transferases (GSTs) are enzymes involved in protecting cells against chemical toxicity and stress. We hypothesized that the GSTM1- and GSTT1-null genotypes and GSTP1 polymorphisms were associated with increased risk for vitiligo. In a hospital-based case-control study of 749 vitiligo patients and 763 age-and sex-frequency-matched healthy controls, GSTM1 and GSTT1 genotypes and GSTP1 (Ile104Val, Ala113Val, Gly169Asp) polymorphisms were analyzed using the multiplex PCR and PCR-restriction fragment length polymorphism technique, respectively. We found that the GSTT1-null genotype was significantly associated with the susceptibility to vitiligo and the GSTM1-null genotype also showed a trend toward vitiligo association. We further analyzed the combined effect of GSTM1-null and GSTT1-null genotypes and showed an increased risk of developing vitiligo. By contrast, no statistically significant association was found between GSTP1 polymorphisms and vitiligo risk. These results suggest that individuals with homozygous deletion of GSTT1 and/or GSTM1 have a greater predisposition to vitiligo.