Researchers Find First Gene for Crohn’s Disease on Human Chromosome 16
Crohn’s Disease results from an autoimmune attack on cells in the lower intestine. This form of inflammatory bowel disease is usually treated with steroids (to suppress the immune response) or surgery (to remove inflamed sections of the bowel that no longer participate in the digestion of foods and their absorption into the bloodstream). Two teams of scientists, one in the U.S. and another in France, have independently identified a candidate gene that is involved in the onset of Crohn’s Disease. This gene, Nod2, is located on chromosome 16, which was sequenced by the DOE Joint Genome Institute. The Nod2 gene is found primarily in monocytes, simple defensive cells of the innate immune system. A mutation in this gene is found twice as frequently in Crohn’s Disease patients as in nonaffected people. This mutation is thought to compromise the ability of monocytes to respond to bacteria that may contribute to the onset of this condition due to an excessive response by a different part of the immune system. The identification of this gene will give researchers a starting place to elucidate the mechanisms behind this inflammatory bowel disease.