However, not every person with the mutation becomes ill, they said. The American and French groups were to present their studies on Monday at a scientific meeting in Atlanta. The complete data will appear in the May 31 issue of the journal Nature, which released the study early. The Nod2 gene encodes a protein associated with the innate immune system. That's the body's primitive first line of defence that recognises invading bacteria and helps to mount a general attack.
Most life forms have an innate immune system.
This is the first time that the plant gene was identified in humans, too. About one in four patients have a family history of the disease, which has encouraged researchers to find a genetic origin. So far, about 15 percent of patients tested have the altered form of the gene. How the mutation contributes to Crohn's Disease is unclear. When the Nod2 gene is damaged, researchers said, the immune system probably overreacts and mistakenly attacks healthy intestinal cells, causing chronic inflammation.