Small ubiquitin-like modifier 4 (SUMO4) polymorphisms and Vogt-Koyanagi-Harada (VKH) syndrome in the Chinese Han population

PURPOSE: To examine whether small ubiquitin-like modifier 4 (SUMO4) polymorphisms were associated with Vogt-Koyanagi-Harada (VKH) syndrome in the Chinese Han population. METHODS: Genotyping for SUMO4 polymorphisms at G-847A, A-504G, A+163G, and C+438T loci was performed on 231 VKH patients and 302 controls using polymerase chain reaction restriction fragment length polymorphism. RESULTS: A decreased frequency of SUMO4 +438 TT genotype was found in VKH patients compared with healthy controls (p=0.009). However, the significance was lost after Bonferroni correction. Human leukocyte antigens (HLA)-DR4 and HLA-DRw53 were significantly associated with susceptibility to VKH syndrome (p=3.21×10(−16) and 7.08×10(−5), respectively). Stratification analysis based on HLA-DR4 and HLA-DRw53 did not show any associations between SUMO4 polymorphisms and VKH syndrome, although there was a big difference in the percentage of certain allele and genotype frequencies between HLA-DRw53 negative patients and controls. There was no significance in clinical findings and gender stratification analysis. CONCLUSIONS: HLA-DR4 and HLA-DRw53 are strongly associated with the susceptibility to VKH syndrome in the Chinese Han population. However, none of the currently known single nucleotide polymorphisms (SNPs) of SUMO4 are associated with this syndrome.