MIF gene polymorphisms confer susceptibility to Vogt-Koyanagi-Harada syndrome in a Han Chinese population

The aim of the study was to determine the association of macrophage migration inhibitory factor (MIF) gene polymorphisms with Vogt-Koyanagi-Harada (VKH) syndrome.

A total of 600 Han Chinese VKH patients and 600 healthy controls were genotyped for rs755622 and rs2096525 of MIF by PCR-restriction fragment length polymorphism (PCR-RFLP) assay. Data were analyzed by χ(2) analysis.

Genotype distribution in controls was in Hardy-Weinberg equilibrium. The frequencies of the rs755622 GG genotype and G allele were significantly lower in VKH patients compared with controls (Pc = 0.006 and 0.016). Stratification analysis showed decreased frequencies of the rs755622 GG genotype and G allele in patients, respectively with headache, tinnitus, alopecia, poliosis or vitiligo compared with controls (all Pc < 0.05). rs2096525 genotype and allele frequencies were not different between VKH patients and controls. However, a lower frequency of the rs2096525 TT genotype was observed in patients with headache compared with controls (Pc < 0.05). The frequencies of the rs2096525 T allele in patients with headache or vitiligo were significantly decreased compared with controls (Pc = 8.54 × 10(-4) and 0.012). In addition, the results showed a significantly increased frequency of the combined rs755622/rs2096525 CT haplotype and a decreased frequency of the GT haplotype in VKH patients compared with controls.

Our study identified a strong association of rs755622 with VKH syndrome and certain clinical features. rs2096525 was associated with certain clinical features of VKH syndrome. The results also suggested that the CT and GT haplotypes were associated with VKH syndrome.