Susceptibility to ankylosing spondylitis: no evidence for the involvement of transforming growth factor beta 1 (TGFB1) gene polymorphisms.

BACKGROUND Genetic factors are thought to be crucial in the pathogenesis of ankylosing spondylitis. Transforming growth factor beta 1 (TGF beta 1) is a multifunctional cytokine that plays a key role in inflammation. Two functional single nucleotide polymorphisms (SNPs) in the TGFB1 gene have been described: TGFB1 T869C and TGFB1 G915C. OBJECTIVE To determine whether these SNPs contribute to ankylosing spondylitis susceptibility or its disease characteristics. METHODS Genomic DNA was isolated from the peripheral blood of 134 patients with ankylosing spondylitis and 194 healthy blood donors. All subjects were unrelated and of white Dutch ethnicity. The diagnosis of ankylosing spondylitis was made according to the modified New York criteria. The TGFB1 T869C and TGFB1 G915C SNPs were genotyped by a polymerase chain reaction-single strand conformation polymorphism haplotyping method. RESULTS No significant differences were found between patients and controls in genotype, allele, and haplotype frequencies or in the carrier rate of the rare alleles of the TGFB1 T869C and TGFB1 G915C SNPs. CONCLUSIONS TGFB1 T869C and TGFB1 G915C SNPs are not major factors in the susceptibility to ankylosing spondylitis or its disease characteristics.