Functional polymorphisms of the <i>FAS</i>/<i>FASLG</i> genes are associated with risk of alopecia areata in a Chinese population: a case-control analysis

Abstract

BACKGROUND: The Fas/Fas ligand system plays a key role in regulating cell growth and apoptosis. Previous findings have suggested that FAS and FASLG polymorphisms are associated with systemic lupus erythematosus, autoimmune hepatitis, vitiligo and other autoimmune-related disorders. However, to the best of our knowledge, there is no reported study on the associations between FAS and FASLG polymorphisms and the risk of alopecia areata. OBJECTIVES: To investigate the associations between FAS and FASLG polymorphisms and the risk of alopecia areata in a Chinese Han population. METHODS: In a hospital-based case-control study of 84 patients with alopecia areata and 84 controls, we genotyped FAS 1377G>A, FAS 670A>G and FASLG 844T>C polymorphisms and assessed their association with alopecia areata risk. RESULTS: We found that a reduced risk of alopecia areata appeared to be associated with the FAS 670AG genotype [adjusted odds ratio (OR) 0.43; 95% confidence interval (CI) 0.22-0.86] when compared with the FAS 670AA genotype, but no risk was associated with any of the FAS 1377G>A and FASLG 844T>C genotypes. In the combined analysis, we found that the presence in individuals of two at-risk alleles of the three FAS/FASLG polymorphisms was associated with a lower risk of alopecia areata (adjusted OR 0.21; 95% CI 0.05-0.89) when compared with the presence of six at-risk alleles. CONCLUSIONS: These results suggest that genetic variants in the FAS and FASLG genes may contribute to the aetiology of alopecia areata.