A group of scientists forming IBD Genetics Consortium have identified a new gene linked to the developement of Crohn's disease, also known as ulcerative colitis, or inflammatory bowel disease (IBD). After testing more than 300,000 single nucleotide polymorphisms, or SNPs, in people with Crohn's disease, three genes seemed to be most strongly associated with Crohn's disease. Two were in the CARD15 gene, while the third SNP was located in a different gene on a different chromosome.

The third gene apparently coded for a protein that is part of the immune cell receptor for interleukin-23 (IL-23), an important mediator of inflammation in the body. Although several polymorphisms of IL-23 were associated with a significantly increased risk of developing IBD, one appeared to confer a very strong protection against IBD.

"We are not sure yet what it means in terms of improving treatments for IBD patients. But, we speculate that blocking the activity of IL-23 or manipulating its pathway will be an effective way to manage IBD.

Preliminary clinical trials indeed demonstrated that using monoclonal antibody that blocks IL-23 and a related inflammatory mediator did improve the conditions. These findings suggest that the IL-23 pathway may lead to more individualized, gene-targeted therapies for IBD.

For more details, see the feature report from the UPMC News Bureau, or the manuscript published in Science Express.

[Image: Schematic of patterns of disease in CD. The three most common sites of intestinal involvement in Crohn's disease are ileal, ileocolic and colonic. Source: Wikipedia]