Toll-like receptor gene polymorphisms in Indian patients with inflammatory bowel disease

Abstract

Background: Defective innate immune recognition of gut microbes may be one reason for the genesis of inflammatory bowel disease (IBD). Genetic defects in IBD show considerable variation between populations. This study evaluated three single-nucleotide polymorphisms (SNP) in the toll-like receptor (TLR) genes in patients with IBD and healthy controls. Methods: DNA isolated from peripheral blood of 200 IBD patients (100 Crohn’s disease and 100 ulcerative colitis) and 100 healthy controls were subjected to polymerase chain reaction and restriction enzyme digestion for three SNPs in TLR4 (D299G, rs4986790), TLR5 (392 stop codon, rs5744168) and TLR9 (-1486 T/C, rs187084) genes, and genotypes assigned according to the restriction fragment length polymorphism pattern. Results: Minor allele frequencies for the 3 polymorphisms were not significantly different between IBD patients and healthy controls. The TLR4 rs4986790 minor allele (G) frequency was 27/200 in controls compared to 48/400 in IBD (odds ratio [OR] 0.87, 95% confidence interval [CI] 0.52–1.44, P = 0.6007). The TLR5 rs5744168 minor allele (T) frequency was 19/200 in controls compared to 45/400 in IBD (OR 1.20, 95% CI 0.63–2.12, P = 0.5132). The TLR9 rs187084 minor allele (C) frequency was 71/200 in controls compared to 129/400 in IBD (OR 0.88, 95% CI 0.61–1.26, P = 0.4261). Conclusion: These three polymorphisms in the TLR genes were not associated with IBD in the Indian population.