Investigation of the association of Vogt-Koyanagi-Harada syndrome with IL23R-C1orf141 in Han Chinese Singaporean and ADO-ZNF365-EGR2 in Thai

Background We performed a multistage genome-wide association study of Vogt-Koyanagi-Harada (VKH) syndrome in a Han Chinese population and identified two novel non-human leukocyte antigen candidate regions previously. The aim of the study was to replicate the association of IL23R-C1orf141 and ADO-ZNF365EGR2 with VKH syndrome in four sets of multinational populations in Asia. Method We conducted a candidate genes association study involving 185 patients with VKH syndrome and 287 normal controls from Han Chinese Singaporeans, nonHan Chinese, Thais and Koreans. Genotyping of 16 single nucleotide polymorphisms (SNPs) within IL23R-C1orf141 and ADO-ZNF365-EGR2 loci was performed using the Sequenom MassARRAY system or by Taqman SNP assays. Results Eight SNPs in IL23R-Clorf141 showed an association with VKH syndrome only in Han Chinese Singaporeans (p=8.49x10(-5) to 1.02x10(-3), pcorrection=1.69x10(-4) to 2.04x10(-3)) but not in the other groups tested. One SNP rs1884444 in IL23R-Clorf141 was found to be weakly associated with VKH syndrome in the Han Chinese Singaporeans, but significance was lost following Bonferroni correction for multiple comparisons. Five SNPs in ADO-ZNF365-EGR2 were found to be associated with VKH syndrome in Thai patients with VKH (p=0.014, p(c)=0.028) but not in the other three ethnic groups tested. Conclusions This study confirmed the genetic associations between SNPs in IL23R-C1orf141 and VKH syndrome in Han Chinese Singaporeans but not in other Asian populations. In addition, we also successfully replicated the association of VKH syndrome with ADOZNF365-EGR2 in a Thai population.