New genetic discovery sheds light on ulcerative colitis

In a study published by Nature Genetics on January 4, 2009, an international team of geneticists and gastroenterologists led by Mount Sinai Hospital’s Dr. Mark Silverberg have discovered a new genetic link to ulcerative colitis, an inflammatory bowel disease that affects approximately 200,000 Canadians.

“This research found two new genetically predisposing factors for colitis which gives us a better understanding of why people get the disease, and will eventually lead to improved therapies and potentially prevent it altogether,” said Dr. Silverberg, one of the lead authors of the paper, associate member of the Samuel Lunenfeld Research Institute of Mount Sinai Hospital and the Gale and Graham Wright Research Chair in Digestive Diseases. “There is no known cause for ulcerative colitis and Canadians have one of the highest rates of incidence of this disease.”

Ulcerative colitis is a life-long disease that usually begins in young adulthood and affects the inner layer of the colon, or large bowel. The disease can cause sudden life-threatening complications, but is usually controlled by drug therapy or surgery.

The research employed a genome-wide study that analyzed the DNA of more than 1,000 patients and over 2,000 control samples using simple blood tests. The team’s findings showed significant evidence of susceptibility in two novel regions located adjacent to genes encoding the proteins phospholipase A2 and interferon gamma. These proteins play roles in inflammatory responses and immune system regulation.

“This is a superb example of the promise of individualized medicine,” said Dr. Jim Woodgett, Director of Research at the Samuel Lunenfeld Research Institute. “As a clinician-scientist, Dr. Silverberg has pinpointed new gene variations that predispose to this debilitating disease that will allow more precise tailoring of the most effective therapy to particular patients.”

The research was conducted by the NIDDK IBD Genetics Consortium and was funded by the National Institutes of Health(NIH)/National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and the Crohn’s and Colitis Foundation of Canada (CCFC).