Faulty Gene Found in People With Crohn's Disease
May 21, 2001 -- For the first time, scientists have identified a faulty gene that triggers an abnormal reaction to bacteria invading the gut of some people with Crohn's disease. Crohn's is a potentially devastating disease that affects the digestive tract.
American and European scientists, working separately, announced the promising findings today at a meeting of digestive disease experts in Atlanta. Knowledge of the gene and how it works in some -- and fails to work in others -- could help doctors find better, more specific ways to treat the debilitating disease that affects 1 in every 1,000 people in Western countries.
The American group was led by Gabriel Nunez, MD, who is an associate professor of pathology at the University of Michigan Medical School in Ann Arbor; the European group was led by Prof. Gilles Thomas of Fondation Jean Dausset, CEPH, in Paris. The full reports of both research groups appear in the May 31 issue of Nature.
Both groups of researchers believe the gene, called Nod2, is supposed to act as a sort of guardian that protects the body against bacteria that invade the intestines. In at least some people with Crohn's disease, the gene appears to be damaged and does not respond properly to keep harmful bacteria at bay. Instead, the immune system is triggered to attack the lining of the intestines -- causing sores and ulcerations -- instead of the bacteria. Nunez and colleagues made their findings by testing samples of genetic material from affected people with a high rate of Crohn's disease in their families.
"We've known for a long time that there is some role for genes and also for bacteria in the gut. The function was the missing link connecting those two things. Now we know Nod2 regulates the bacteria. It makes a lot of sense," says Nunez.
Whether people with Crohn's disease who have no history of it in their family -- so-called sporadic cases -- also may have the same or similar faulty gene is not known, because only people with the familial type were studied.
The next step in the research will be to start looking for the faulty gene in large groups of people with sporadic cases.