The aim of this study is to investigate the association of the polymorphisms in tumor necrosis factor (TNF) and granulin (GRN) with ankylosing spondylitis (AS) in a Chinese Han population. Five single nucleotide polymorphisms (SNPs) covering TNF and six SNPs covering GRN were investigated in 861 Chinese Han AS patients and 864 healthy controls. For rs1799964, the C allele was linked to reduced risk of AS (p < 0.0001, OR = 0.60, 95% CI = 0.50-0.71). The carriers of the C/C homozygote showed a significantly lower risk of AS compared with the TT homozygote and the C/T heterozygote under the recessive model (p < 0.0001, OR = 0.23, 95% CI = 0.12-0.45). For rs1800629, the A allele was also linked to reduced risk of AS (p < 0.0001, OR = 0.54, 95% CI = 0.39-0.74). For rs1800630, the A allele was also linked to reduced risk of AS (p < 0.0001, OR = 0.59, 95% CI = 0.48-0.72). The carriers of the A/A homozygote showed a significantly lower risk of AS compared with the C/C homozygote and the A/C heterozygote under the recessive model (p < 0.0001, OR = 0.18, 95% CI = 0.07-0.47). For rs769178, the T allele was linked to increased risk of AS (p < 0.0001, OR = 2.59, 95% CI = 2.18-3.09). The carriers of the T/T homozygote showed a significantly higher risk of AS compared with the GG homozygote and the G/T heterozygote under the recessive model (p < 0.0001, OR = 3.34, 95 %CI = 1.95-5.72). There was no significant difference between the AS patients and the controls in the genotype or allele frequencies of rs361525. For GRN, there was no significant difference between the AS patients and the controls in the genotype or allele frequencies of rs25646, rs3760365, rs3785817, rs4792939, rs5848, rs850713 (p > 0.05). This study indicates that polymorphisms in TNF are related to AS, but polymorphisms in GRN are not related to AS susceptibility in a Chinese Han population.
Keywords: Ankylosing spondylitis; GRN; Single nucleotide polymorphisms; TNF.