Crohn disease

Crohn disease is a chronic, relapsing inflammatory bowel disease characterized by granulomatous inflammation, primarily localized to the terminal ileum. Most patients have involvement of the small intestine, but the other area of gastrointestinal tract may also be affected. In Western populations, over 50% of patients possess NOD2 mutations. Evidence exists that the NOD2 polymorphisms impair NF-kappaB activation and cytokine secretion in response to its ligand. The pathogenesis of Crohn's disease is also attributed to intestinal bacteria that may initiate mucosal inflammation in genetically susceptible individuals. Additional genes associated with the disease are recently being identified.