Gene associated with ulcerative colitis uncovered researchers

For as long as seven-year-old Jonathan Wexler can remember, he has taken sweet orange medicine every day to manage his ulcerative colitis symptoms.

When he was only eight months old, Jonathan became the youngest patient to be diagnosed with ulcerative colitis, a form of inflammatory bowel disease (IBD), at The Hospital for Sick Children (SickKids).

In a new study led by SickKids and the University of Toronto, researchers identified a gene that may play an important role in the development of ulcerative colitis. The results strongly implicate the RAC1 gene as a potential target for new therapies.

Over the past decade, the number of children living with inflammatory bowel disease (IBD) in Ontario has increased by 30 per cent, mostly due to the increased diagnosis of kids under 10 years old. IBD is thought to be caused by a combination of genetics and an immune response to bacteria in the gut, but the exact cause remains unknown.

This study, published in the August 1 edition of Gastroenterology, is the largest Canadian study of its kind. It included over 3,000 participants from Toronto, the United States and Scotland. The average age of participants was 16.

The study was first conducted in a local discovery cohort and found that increased RAC1 gene expression was associated with susceptibility to ulcerative colitis. Scientists took this discovery to the next step and tested this association in animal models. They found that reducing RAC1 gene expression led to protection from developing the disease.