Association between single nucleotide polymorphism in TNF-α gene and ankylosing spondylitis in Chinese Han population

Objective:To examine the single nucleotide polymorphisms (SNPs) in TNF α gene in Chinese Han population with ankylosing spondylitis (AS). Methods: An correlation analysis was performed in a case control cohort of 107 AS cases and 116 controls. Three SNPs located in the promoter of TNF α gene (-1 031T/C -863C/A,-857C/T) and 2 SNPs in intron (IVS1 +123C/T and IVS3 +51A/G) were examined by direct sequencing and real time fluorescence PCR with allele specific amplification. Haplotype inference software programs were used to caculate haplotype frequencies, and the relationship between haplotypes and AS was studied. Results: The frequencies of allele T at position -857 and allele A at position -863 significantly increased in AS cases vs controls, so were their genotype frequencies. These differences remained significant after Bonferroni's correction. Significant differences in the overall distribution of haplotype frequencies based on 3 and 2 SNP markers were found between 2 groups, with the most significant increase in the frequency of TNF -1 031C/-863C/-857T haplotype based on 3 SNP markers in AS patients. Conclusion: Our data demonstrate that the AS is highly associated with -857C/T -863C/A SNPs, and the inferred haplotypes of TNF α gene in Chinese Han population.