In multivariate analysis, lack of a university degree, not being a member of a patient association, not receiving anti-tumor necrosis factor alpha (anti-TNFα) treatment, duration of IBD ≤3 years, male sex, and age >38 years were independent risk factors of a poor IBD-INFO knowledge score.
TNF-alpha is a key cytokine known to play a role in inflammatory response, and the locus for the gene is found in the IBD3 region on chromosome 6p21, known to be associated with an increased risk for IBD.
Nucleotide oligomerization domain (NOD2) and human leukocyte antigen (HLA) genes are the most extensively studied genetic regions (IBD1 and IBD3 respectively) in IBD.
We also find confirmatory evidence for linkage between the IBD3 locus and Crohn's disease (lod = 2.26 at D6S2439) but not ulcerative colitis or inflammatory bowel disease.
It is now well established that susceptibility to inflammatory bowel disease is in part genetic, with one localization on chromosome 6 (IBD3) having been replicated in a number of populations.
Recent genome scans and replication studies have identified replicated linkage between CD and a locus on chromosome 16 (the IBD1 locus), replicated linkage between IBD (especially UC) and a locus on chromosome 12q (the IBD2 locus), and replicated linkage between IBD (especially CD) and a locus on chromosome 6p (the IBD3 locus).