Discovery offers hope of better-targeted therapy for millions of people with IBD

A team of researchers in Canada and the United States conducted an association study in 2006, designed to explore the effects that genes have on each other. The scan led to an unexpected discovery – a strong protective relationship between a gene (IL23R) on chromosome 1p31 and Crohn’s disease.

As reported in Science Express, the online publication of the journal, Science, to identify additional genes associated with IBD, the international team of researchers scanned the genome in approximately 3,000 people with inflammatory bowel disease, and 1,000 people without IBD to identify any similarities and differences.

An uncommon coding variant (rs11209026, c.1142G>A, p.Arg381Gln) confers strong protection against Crohn’s disease. Additional variants on IL23R showed further association with IBD. This breaks the way for new research looking for treatments linked to these findings, and encourages a switch from looking at the genetics of what makes us sick, to the genetics of what keeps us healthy.

Genetic factors play significant roles in the development of inflammatory bowel diseases. There are some genetic variances known today, including an increased incidence of the disease in Ashkenazi Jews, an increased familial incidence, and that identical twins are more likely to have the same disease or no disease at all whereas fraternal twins do not have this same uniformity of disease incidence. Previous genetic studies have linked IBD to several variances and while Crohn’s disease and ulcerative colitis share some similarities, they are very different in many ways and further genetic studies could help shed light on the specifics of the variances.

First published in the Inside Tract® newsletter issue 158 – November/December 2006