Association of KIF21B genetic polymorphisms with ankylosing spondylitis in a Chinese Han population of Shandong Province

Previous studies have found that the kinesin family member (KIF) 21B may contribute to the autoimmune disease process. It has been reported that the KIF21B gene is relevant to the pathogenesis of Crohn's disease (CD) and ulcerative colitis (UC). We hypothesized that KIF21B might be a key gene for ankylosing spondylitis (AS) development. To test this hypothesis, 11 tag single nucleotide polymorphisms (SNPs) covering KIF21B were investigated in 904 Chinese (Han ethnic) patients of Shandong Province with AS and 898 age- and sex-matched controls of the same ethnic origin. The T allele of rs756254 was linked to increased risk of AS (P = 0.022). The AA genotype of rs296560 and TT and AT genotypes of rs756254 were also relevant with AS (P = 0.044, P = 0.033, and P = 0.033, respectively). Haplotype analysis identified that the KIF21B gene region contains two haplotype blocks of eight and two SNPs, respectively. The haplotype GCGGTAAA in block 1 appeared to reduce the risk of AS (P = 0.005), while the haplotype AA in block 2 was significantly associated with an increased risk of AS (P = 0.039). There were no significant differences between the AS patients and the controls in polymorphisms of rs10920091, rs3198583, rs56368827, rs3738255, rs296565, rs12087649, rs12568529, rs7536000, and rs957957. These results indicated that KIF21B was associated with AS in a Chinese population of Shandong Province.