NEW YORK (Reuters) -- Researchers have identified gene segments that may increase a person's susceptibility to two of the most common gastrointestinal ailments -- Crohn's disease and ulcerative colitis.
The findings suggest that the two disorders, which both cause intestinal inflammation, chronic diarrhea, fever, and abdominal pain are, indeed, closely related, with some genes contributing to both disorders, according to the report in the October issue of Nature Genetics.
"We provide strong evidence for the presence of susceptibility [genes] for both Crohn's disease and ulcerative colitis on chromosome 3, 7, and 12," wrote lead study author Dr. Jack Satsangi, of the Radcliffe Infirmary in Oxford, U.K. "The results of the present study have important implications for further studies of the pathogenesis of the inflammatory bowel diseases," he said.
Satsangi and colleagues looked at 160 families with 186 pairs of siblings with inflammatory bowel disease and found that those with the disease were more likely to have a particular gene segment on chromosome 12.
The disease was also associated with gene segments on chromosome 3 and 7, although the association was not as strong as for chromosome 12.
It's not clear exactly what gene on the chromosome increases the susceptibility to the disease, according to the report. However, there are genes on chromosome 7 that code for intestinal mucous proteins and growth factors. The study did not find an association with gene segments on chromosome 16, an area that had been indicated in previous studies.
About 100-200 people out of 100,000 have Crohn's disease or ulcerative colitis, making inflammatory bowel disease one of the most common gastrointestinal disorders. Crohn's disease can affect any area of the digestive tract, but often occurs where the small intestine meets the large intestine. Ulcerative colitis, on the other hand, almost always involves the lower part of the digestive system, the colon and rectum.
While both disease have a serious impact on digestion, they can also cause problems elsewhere in the body, including swollen and inflamed joints, skin problems, and inflammation of the iris of the eye. The cause of the disorders is unknown, but they often appear in family members, and genes are thought to play an important role.
SOURCE: Nature Genetics (1996;14:199-201)
