Overlapping and Distinct FAS/FASLG Gene Polymorphisms in Alopecia Areata in an Iranian Population

ABSTRACT

Alopecia areata (AA) is considered to have a multifactorial etiology and polymorphisms in certain genes have been shown to be associated with AA. Although several reports have investigated the effect of FAS/FAS ligand (FASLG) gene variations with predisposing to AA, genetic association of disease, however, varies among different ethnicities and no data have so far been reported in Iranian population. The present study aimed to uncover a possible association between variations in FAS/FASLG genes and AA. Genomic DNA was extracted from all samples and the SNPs of FAS (rs1800682) and FASLG (rs5030772) genes were genotyped in AA patients and controls. In addition, gene expression of FAS/FASLG was assessed by RT-PCR. Regarding FASLG, the frequency of the G-allele was significantly higher in the patients compared to the controls, indicating that the G-allele at this locus could be a risk for developing AA. In contrast, no association was found for rs1800682 (FAS) with AA. Similarly, compared to controls, FASLG gene expression was upregulated. While no association between clinical−demographic characteristics of the AA patients and their genotypes in FAS/FASL variations was observed, multivariate regression analysis indicated a correlation between the incidence of AA disease and its familial history as well as AG/GG genotypes of FASLG (rs5030772). In conclusion, our data indicate an association between FASLG rs5030772 variation and AA. However, previously reported the association of FAS rs1800682 polymorphism with AA was not observed here. These findings highlight overlapping and distinct genetic polymorphisms in an Iranian cohort which might influence the susceptibility to AA.

KEYWORDS:

• Autoimmune disease
• alopecia areata
• FAS
• FAS ligand
• gene polymorphism

Acknowledgments

We would like to thank Medical and Nursing staff of the Skin Research Center, Shohada Tajrish and Loghman Hakim hospitals at Tehran, Iran for helpful collaboration.