TLR5 Polymorphisms rs2072493, rs5744174, and rs5744168 Are Not Genetic Risk Factors for Chronic <i>Helicobacter pylori</i> Infection in Indian Tamils

<p>The incidence of <i>Helicobacter pylori</i> (<i>H. pylori</i>) infection and gastric cancer is on the rise in India, and the genetic factors influencing the increased susceptibility in Indian population remain obscure. Toll-like receptors (TLRs) play a major role in innate immune system and genetic polymorphisms affecting their function were reported to enhance the risk for <i>H. pylori</i> infection. Seventy-seven patients (<i>n</i> = 77) diagnosed with <i>H. pylori</i> infection and 230 healthy subjects were recruited in this study. The rs2072493, rs5744174, and rs5744168 polymorphisms within TLR5 gene were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and Tetra-ARMS PCR genotyping techniques. Present study revealed that these studied polymorphisms are less frequent in south Indian Tamils and thus failed to confer a significant risk to develop chronic <i>H. pylori</i> infections. The distribution of ancestral allele of rs2072493 polymorphism conferred resistance to develop chronic <i>H. pylori</i> infection in our population (<i>p</i> = 0.024; OR  =  0.53; 95% CI: 0.3–0.91). The lesser incidence of polymorphic alleles suggests that the TLR5 gene is under genetic selection pressure to withstand the prevailing endemic infections among south Indian Tamils.</p>