Association of IL12B polymorphisms with susceptibility to Graves ophthalmopathy in a Taiwan Chinese population

Background Interleukin 12B (IL12B) gene polymorphisms have been linked to several inflammatory diseases, but their role in the development of Graves ophthalmopathy (GO) in Graves disease (GD) patients is unclear. The purpose of this study was to investigate the disease association of IL12B single nucleotide polymorphisms (SNPs). Methods A Taiwan Chinese population comprising 200 GD patients with GO and 271 GD patients without GO was genotyped using an allele-specific extension and ligation method. Hardy-Weinberg equilibrium was estimated using the chi-square test. Allele and genotype frequencies were compared between GD patients with and without GO using the chi-square test. Results The genotype and allele frequencies of examined SNPs did not differ between GD patients with and without GO. Although the genotype distribution remained nonsignificant in the sex-stratified analyses, the frequency of the T allele at SNP rs1003199 was significantly higher in patients with GO in the male cohort (P = 6.00 × 10-3). In addition, haplotypes of IL12B may be used to predict the risk of GO (P = 1.70 × 10-2); however, we could not prove the statistical significance of analysis after applying the Bonferroni correction. Conclusions Our results provide new information that the examined IL12B gene polymorphisms may be associated with susceptibility to GO in the Taiwan Chinese population in a sex-specific manner. This conclusion requires further investigation.