Study doubles genetic regions associated with inflammatory bowel diseases

Montreal, QC – Crohn’s disease and ulcerative colitis, the two most common forms of inflammatory bowel diseases (IBD), are chronic inflammatory digestive disorders affecting 230,000 Canadians. An international team of scientists has thrown new light on the genetic basis of these diseases.

Dr. John Rioux, researcher at the Montreal Heart Institute and Associate Professor of Medicine at the Université de Montréal, is one of the researchers who have identified 71 genetic regions newly associated with IBD, increasing the total number discovered to date to 163.

In one of the largest studies of its kind ever conducted, the researchers conducted a “meta-analysis” of 15 previous genomic studies of either Crohn’s disease (CD) or ulcerative colitis (UC), the two most common forms of IBD, creating a large dataset that combined genetic information from some 34,000 individuals who took part in those studies. The results then formed part of a second meta-analysis that included data from new genome-wide scans of more than 41,000 DNA samples from CD/UC patients and healthy comparison subjects collected at 11 centers around the world by the International IBD Genetics Consortium.

The study points out that these regions showed a striking overlap with those implicated in autoimmune diseases and in immune deficiencies.  Even more surprising was the observation of a significant overlap with genetic regions controlling our response to microbial infections such as in the case of tuberculosis. These highlights were published in the prestigious scientific journal Nature on November 1, 2012.