Relationship between the 5′-flanking region of tumor necrosis factor(TNF)-alpha gene polymorphism and ankylosing spondylitis

Objective:To investigate polymorphism in the 5′-flanking region of tumor necrosis factor(TNF)-alpha gene in relation to susceptibility to ankylosing spondylitis(AS).Methods:Genomic DNA from 136 AS patients with B27 positive and 127 matched healthy controls were analyzed to TNF-α gene three polymorphisms loci(-857,-863 and-1031) by Sequence-specific primer polymerase chain reaction(SSP-PCR) and we compared the genotype and allele frequency of TNF-α in different populations from different area.Results:In AS patients TNF-α-857 genotype CC,CT and TT are 64.0%,35.3% and 0.7% respectively,TNF-α-863 genotype CC,CA and AA are 68.4%,30.0%and 1.5% respectively,and TNF-α-1031 genotype TT,TC and CC are 66.2%,32.4% and1.5% respectively;The allele frequency of C and T in TNF-α-857 are 81.6% and18.8% respectively.The allele frequency of C and A in TNF-α-863 are 83.5% and 16.5% respectively.The allele frequency of T and C in-1031 are 82.4% and 17.6% respectively;In healthy controls TNF-α-857 genotype CC,CT and TT are 70.9%,27.6% and 1.6% respectively,TNF-α-863 genotype CC,CA and AA are 68.5%,29.9% and 1.6% respectively,and TNF-α-1031 genotype TT,TC and CC are 69.3%,29.1% and 1.6% respectively;The allele frequency of C and T in TNF-α-857 are 84.6% and 15.4% respectively.The allele frequency of C and A in TNF-α-863 are 83.5% and 16.5% respectively.The allele frequency of T and C in-1031 are 83.9% and 16.1% respectively,No significant differences were found in the distribution of TNF-α gene three loci genotypes and allele frequencies between AS patients and controls;The distribution of TNF-α gene polymorphism in Chinese Han population is almost the same as it is in Japanese and Koreans populations,The distribution of TNF-α-863 and-1031 genotypes and allele frequency in Chinese Han population is almost the same as it is in United Kingdom,Dutch and Sweden population,but significant difference was found in the distribution of TNF-α –857T allele frequencies between Asia populations(Chinese,Japanese and Koreans) and Europe populations(United Kingdom,Dutch and Sweden).Conclusion:Our results indicate that the there may be no association of the TNF-α gene three polymorphisms loci(-857,-863 and-1031) with ankylosing spondylitis in Chinese Han population.