A meta-analysis of P1371Q polymorphisms in DLG5 gene with reduced risk of Crohn's disease in European

Background: The DLG5-e26 and P1371Q polymorphisms in the discs large homologue 5 (DLG5) gene may influence the susceptibility to inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC); however, existing results remain inconclusive. Aim: Our aim was to investigate the association between the DLG5 polymorphisms and IBD risk by meta-analysis. Methods: Fourteen studies were extracted from a search of PubMed, Embase, Chinese National Knowledge Infrastructure (CNKI) and Google Scholar databases before December 2015. We estimated the odds ratio (OR) and 95% CI using fixed-effect model or random-effect model. Results: The minor A allele at P1371Q decreased risk of CD in European (A vs. C, OR = 0.843, 95% CI = 0.714-0.995, P = 0.044), however, it increased the risk of IBD in North American (1.751 (95% = CI 1.249-2.455), P = 0.001). No significant associations were found between DLG5-e26 and IBD (delA vs. insA in IBD: 1.053, 95% CI = 0.976-1.136; CD: 1.031, 95% CI = 0.938-1.132; UC: 1.007, 95% CI = 0.832-1.219), and between P1371Q and IBD (A vs. C in IBD: 1.050, 95% CI = 0.930-1.184; CD 0.994, 95% CI = 0.802-1.231; UC: 1.124, 95% CI = 0.962-1.313). Conclusions: DLG5-e26 polymorphisms in the DLG5 have no relationship with IBD in either CD or UC, but P1371Q reduces the risk of CD in European, while increases the risk of IBD in North American.