Susceptibility loci reported in genome‐wide association studies are associated with Crohn’s disease in Canadian children

Aliment Pharmacol Ther 31, 1186–1191 Summary Background Recent genome‐wide association studies based on adult and paediatric populations have implicated >30 genes/loci as susceptibility loci for Crohn’s disease (CD). Aims To investigate whether reported genes/loci were also associated with CD in Canadian children. Design and Methods A case‐control design was implemented at three paediatric gastroenterology clinics in Canada. Children ≤18 years of age with a confirmed diagnosis of CD were recruited along with controls. Single nucleotide polymorphisms (SNPs) in five genome‐wide association studies reported genes/loci were genotyped. Associations between individual SNPs and CD were examined. Results A total of 406 cases and 415 controls were studied. The mean (±s.d.) age of the cases was 12.3 (±3.2) years. Most cases were male (56.6%), had ileo‐colonic disease (L3 ± L4, 52.0%) and inflammatory behaviour (B1 ± p, 86.9%) at diagnosis. Allelic association analysis (two‐tailed) showed that three of the five targeted SNPs were significantly associated with overall susceptibility for CD (ZNF365, r10995271, P = 0.001; PTPN2, rs1893217, P = 0.005; STAT3, rs744166, P = 0.01). Associations with SNP rs4613763 in the PTGER4 locus were marginally nonsignificant (P = 0.07). The ZNF365 and STAT3 SNPs were predominantly associated with ileal disease with or without colonic involvement. Conclusion The identified susceptibility genes/loci for adult‐onset CD also confer risk for paediatric‐onset CD.