April 28 (HealthDay News) -- The inflammatory bowel diseases ulcerative colitis and Crohn's disease appear to share several genetic variants and risk factors, two new British studies suggest.

Though similar in many ways, the two diseases are distinct, and scientists have been trying to pinpoint the underlying relationship between them to improve their understanding of and treatment for both. The latest findings, expected to be published online in the April 27 issue of Nature Genetics, may be a significant step forward.

Ulcerative colitis and Crohn's disease affect one in 250 individuals of Northern European descent. Ulcerative colitis is a common inflammatory bowel disease, while Crohn's disease is a related, but chronic disorder of the intestine.

In the first study, researchers identified ECM1, a gene variant that encodes a protein secreted by cells to activate a key immune regulator as tied to the risk of colitis. They also found that five genes previously linked to the probability of developing Crohn's disease are also common to ulcerative colitis, while three others are not.

In the second study, several of 50 previously reported susceptibility loci for Crohn's disease were deemed risk variants for both diseases. Three others were found to be specific to Crohn's disease and three specific to ulcerative colitis.

SOURCE: Nature Genetics, news release, April 27, 2008