The Role of FOXP3 Polymorphisms in Graves' Disease with or without Ophthalmopathy in a Turkish Population

Abstract

Objectives: Forkhead box P3 (FOXP3) gene polymorphisms have been evaluated in many autoimmune diseases, including Graves' disease (GD), in different populations. However, those polymorphisms have not been analyzed in GD or Graves' ophthalmopathy (GO) in the Turkish population. In this study, we aimed to evaluate the frequency of FOXP3 polymorphisms in GD with or without ophthalmopathy in a Turkish population.

Materials and methods: The study included 100 patients with GO, 74 patients with GD without ophthalmopathy, and 100 age- and sex-matched healthy controls. In all study participants, rs3761547 (-3499 A/G), rs3761548 (-3279 C/A), and rs3761549 (-2383 C/T) single nucleotide polymorphisms (SNPs) were detected using the polymerase chain reaction-restriction fragment length polymorphism method. The chi-square test was used to evaluate genotype and allele frequencies. Odds ratios and 95% confidence intervals were calculated for genotype and allele risks.

Results: In the patient group (including GD with or without ophthalmopathy), the rs3761548 AC and AA genotype and rs3761549 CT genotype were significantly more frequent than in the control group (all p<0.05). No genotypic and allelic differences were observed for rs3761547 between the patient and control groups (all p>0.05). There was no statistically significant difference between the GO and GD without ophthalmopathy groups concerning the allele and genotype frequencies of all three FOXP3 SNPs (all p>0.05).

Conclusion: The AC and AA genotypes of rs3761548 (-3279) and CT genotype of rs3761549 (-2383 C/T) were shown to be possible risk factors for GD development in the Turkish population. However, none of the three SNPs was shown to be associated with the development of GO in patients with GD.

Keywords: Forkhead box P3; Graves’ disease; Graves’ ophthalmopathy; single nucleotide polymorphisms.