Association between the IL7R T244I polymorphism and multiple sclerosis risk: a meta analysis

The aim of this study was to explore the association between the IL7R T244I polymorphism (rs6897932) and susceptibility of multiple sclerosis (MS). A comprehensive literature search for relevant studies was conducted on Google scholar, PubMed, the Chinese National Knowledge Infrastructure (CNKI) and the Chinese Biomedical Literature Database (CBM). This meta-analysis was performed using the STATA 11.0 software and the pooled odds ratio (OR) with 95 % confidence interval (CI) was calculated. Seventeen case–control studies were included in this meta-analysis. In total, 17 articles provided data for 15,270 cases and 17,971 controls. The results showed significant association between the IL7R T244I polymorphism and susceptibility to MS (OR = 1.125, 95 % CI: 1.016–1.245, p = 0.024 for C vs. T; OR = 1.176, 95 % CI: 1.078–1.282, p < 0.001 for CC + CT vs. TT; OR = 1.243, 95 % CI: 1.088–1.421, p = 0.001 for CC vs. TT). Stratified analysis of ethnicities also showed significant association in Europeans. However, no association was found in Asians. This study suggested that the IL7R C allele was associated with an increased risk of MS and larger-scale studies of populations are needed to explore the roles played by the IL7R T244I polymorphism during the pathogenesis of MS.