Ulcerative Colitis

Ulcerative colitis belongs to a group of diseases known as inflammatory bowel diseases (IBD), or diseases that cause inflammation in the digestive tract. In ulcerative colitis, small ulcers develop in areas where inflammation has damaged or killed the cells lining the colon. These ulcers usually become infected, which along with the bleeding, causes the colon to empty frequently, resulting in cramping abdominal pain and diarrhea.

Ulcerative colitis is related to another type of IBD called Crohn's disease. The two diseases differ mainly in the depth of the inflammation and location within the digestive tract. Whereas ulcerative colitis affects the colon mucosa, the innermost lining of the colon and rectum, Crohn's disease causes inflammation deeper within the intestinal wall and occurs in other parts of the digestive system, including the small intestine, mouth, esophagus, and stomach.

Symptoms of ulcerative colitis and its complications, vary depending on the extent of inflammation in the rectum and colon. About half of those diagnosed with ulcerative colitis continue to have mild symptoms that come and go, whereas others may experience chronic debilitating symptoms leading to life-threatening complications. Even those with a severe form of the disease may have relatively symptom-free periods between flare-ups.

Ulcerative colitis can occur in people of any age, but the disease is usually first diagnosed in people in their 30s. It is more frequently diagnosed in individuals of European origin and in those of Jewish descent and affects men and women equally.

The direct causes of ulcerative colitis are unknown. Those diagnosed with the disease often also have disorders of the immune system, but it is not known whether they are a cause, a result, or simply a correlate of ulcerative colitis.

Genetic factors are known to play a significant role in the development of the disease. Up to 20% of people diagnosed have a close relative with ulcerative colitis or Crohn's disease.

Nine genetic variants, on chromosomes 1, 3, 6, 10, 12 and 18 have been associated with increased risk of developing ulcerative colitis. Of these, four variants, on chromosomes 1, 3, 10 and 18, have also been associated with increased risk of developing Crohn's disease.

The deCODEme Genetic Scan identifies these variants and uses them to provide customers of European descent with a personalized interpretation of their genetic risk for developing ulcerative colitis.

At present, the necessary scientific information to interpret the genetic risk for customers of other ethnicities is not available. This information will be added as soon as it becomes available and we are assured of its quality.

This content was last reviewed on February 11, 2010.