We provide novel evidence to show that IBD2 is involved in susceptibility to IC and terminal ileal CD in this population, with overrepresentation of IBD2 STR D12S83 (GenBank Z16592.1) allele 7 (g.49_60del[CA](6)) in IC (q = 0.038, P = 0.014) and underrepresentation of allele 8 (g.51_60del[CA](5)) in terminal ileal CD (q = 0.038, P = 0.016).
Our results provide confirmatory evidence for linkage between the IBD2 locus and the inflammatory bowel disease phenotype (lod = 2.12 at GATA91H06) and ulcerative colitis phenotype (lod = 1.44 at GATA91H06), but not the Crohn's disease phenotype.
Association of ulcerative colitis with the inflammatory bowel disease susceptibility locus IBD2 in non-Jewish Caucasians and evidence of genetic heterogeneity among racial and ethnic populations with Crohn disease.
IBD2 thus appears to make a major contribution to UC susceptibility but to have only a relatively minor effect with regard to CD, for which there may be substantially more locus heterogeneity.