Interleukin-17 gene polymorphism is associated with Vogt-Koyanagi-Harada syndrome but not with Behçet's disease in a Chinese Han population.

Interleukin (IL)-17 has been shown to play an important role in certain autoimmune diseases. The present study was performed to investigate the association of IL-17A and IL-17F gene polymorphisms with two autoimmune uveitis entities, Vogt-Koyanagi-Harada (VKH) syndrome and Behçet's disease (BD), in a Chinese Han population. A total of 362 BD patients, 385 VKH syndrome patients, and 412 controls were genotyped for IL-17A/rs2275913 and IL-17F/rs763780 using polymerase chain reaction-restricted fragment length polymorphism. The result showed that the genotype and allele distribution of the two single nucleotide polymorphisms (SNPs) in all subjects were in Hardy-Weinberg equilibrium. A significantly decreased frequency of IL-17F/rs763780 C allele (p = 0.006, p(c) = 0.036) and an increased frequency of TT genotype (p = 0.005, p(c) = 0.030) were observed in VKH patients compared with normal controls. There was no association of the tested two SNPs with BD, even after adjusting gender ratio. Stratification analysis failed to find any association of extraocular manifestations of two uveitis entities and the tested two SNPs. The C allele and TT genotype of rs763780 in the IL-17F gene appear to be associated with protection and susceptibility to VKH syndrome. The tested two IL-17 SNPs are not found to be associated with Behçet's disease.