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-ZNF365-EGR2 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, non-Han 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=8.49×10(-5) to 1.02×10(-3), pcorrection=1.69×10(-4) to 2.04×10(-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, pc=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 ADO-ZNF365-EGR2 in a Thai population.