Variants at the 3p21 locus influence susceptibility and phenotype both in adults and early-onset patients with inflammatory bowel disease

BackgroundTo date, a number of high-profile studies have yielded over 50 inflammatory bowel disease (IBD) disease genes/loci. The polymorphisms rs9858542 (BSN) and rs3197999 (MST1), on 3p21 locus, have been found associated with susceptibility to IBD. We aimed to replicate these associations in adult and early-onset cohorts of IBD Italian patients, by analyzing also potential gene–gene interactions with variants in NOD2/CARD15, IL23R, ATG16L1, and IRGM genes, and investigating genotype–phenotype correlation.MethodsIn all, 1808 patients with IBD, 855 with Crohn's disease (CD) and 953 with ulcerative colitis (UC), including 539 patients with their initial diagnosis