Genetic Background of Uveitis in Chinese Population

Uveitis, known as inflammation of the uvea consisting of the iris, ciliary body, and choroid, is one of the leading causes of blindness in the world. Behcet’s disease (BD), Vogt-Koyanagi-Harada (VKH) syndrome, and acute anterior uveitis (AAU) are three commonly seen uveitis entities in China. Although the precise pathogenesis remains unclear, accumulating evidence shows that complex genetic backgrounds may be implicated in the development of uveitis. Genes encoding for human leukocyte antigens (HLAs) have been shown to be associated with these uveitis entities, including BD (HLA-B51), VKH syndrome (HLA-DR4, DRB1/DQA1), and AAU (HLA-B27). Genome-wide association studies showed that the IL23R locus was a shared risk factor for these three uveitis entities including BD, VKH syndrome, and AAU. In addition, various other non-HLA genes are also associated with BD, VKH syndrome, or AAU, such as IL-10, STAT4, miR-146a, miR-182, and FoxO1. Moreover, copy number variants (CNV) of complement component 4 (C4), IL17F, IL23A, FoxP3, FAS, and C5 have been found to be associated with BD, VKH syndrome, or AAU. In conclusion, these studies support the hypothesis that genetic factors play a key role in the pathogenesis of these uveitis entities.