The haplotypes of various TNF related genes associated with scleritis in Chinese Han

Several studies have stated that TNF-α participates in the pathogenesis of scleritis, but also in several systemic autoimmune diseases and vasculitis, of which some are associated with scleritis. Earlier GWAS and SNP studies have confirmed that multiple SNPs of TNF related genes are associated with many immune-mediated disorders. The purpose of this study was to examine the association of TNF related gene polymorphisms with scleritis in Chinese Han. A case-control study was carried out in 556 non-infectious scleritis cases and 742 normal controls. A total of 28 single-nucleotide polymorphisms (SNPs) were genotyped by the iPLEXGold genotyping assay.

No significant correlations were seen between the individual SNPs in the TNF related genes and scleritis. Haplotype analysis showed a significantly decreased frequency of a TNFAIP3 TGT haplotype (order of SNPs: rs9494885, rs3799491, rs2230926) (Pc = 0.021, OR = 0.717, 95% CI = 0.563-0.913) and a significantly increased frequency of a TNFSF4 GT haplotype (order of SNPs: rs3850641, rs704840) (Pc = 0.004, OR = 1.691, 95% CI = 1.205-2.372) and TNFSF15 CCC haplotype (order of SNPs: rs6478106, rs3810936, rs7865494) (Pc = 0.012, OR = 1.662, 95% CI = 1.168-2.363) in patients with scleritis as compared with healthy volunteers.

This study reveals that a TGT haplotype in TNFAIP3 may be a protective factor for the development of scleritis and that a GT haplotype in TNFSF4 and a CCC haplotype in TNFSF15 may be risk factors for scleritis in Chinese Han.