IFNA1 and IFNA13 Genes Confer Genetic Predisposition to Ankylosing Spondylitis-Associated Uveitis in a Chinese Population.

OBJECTIVES

Uveitis is considered the most frequent extra-articular manifestation of Ankylosing Spondylitis (AS). Genetic factors play an important role in the pathogenesis of AS with uveitis. In this study, we investigated susceptibility genes of AS concomitant with uveitis.

METHODS

First, 9p21-24 was selected as the region of susceptibility genes. Second, several candidate genes were selected from this region by bioinformatics analysis. Thirdly, a two-stage case control study was used to verify these candidate genes. The first stage included 50 AS with uveitis, 50 AS without uveitis, and 145 healthy controls. The qPCR+direct sequencing and cloning sequencing were used to identify SNPs in this stage. The second stage included 245 AS with uveitis, 360 AS without uveitis, and 530 healthy controls.

RESULTS

IFNA1, IFNB1, IFNA8, and IFNA13 were selected as candidate genes. In the first stage, it was found that the frequency of IFNA1 rs28383797 (G allele) and IFNA13 rs653778 (T allele) in AS with uveitis was higher than that in AS without uveitis and healthy controls. In the second stage, more samples were used to verify the two SNPs. After comprehensive data analysis in the two stages, the frequency of rs28383797 G allele and rs653778 T allele in AS with uveitis was significantly higher than that in AS without uveitis (P = 1.9 × 10-7, OR = 2.161, 95%CI = 1.609-2.902 and P = 1.5 × 10-9, OR = 2.028, 95%CI = 1.610-2.554) and healthy controls.

CONCLUSIONS

Rs653778 (T allele) of IFNA13 and rs28383797 (G allele) of IFNA1 were associated with AS concomitant uveitis, and may act as the susceptibility genes of AS with uveitis in the Chinese population.