Analysis of Childhood-onset Inflammatory Bowel Disease Finds New Genes

November 17, 2009

Researchers at The Children's Hospital of Philadelphia identified five new gene regions in young patients with childhood-onset inflammatory bowel disease.

Researchers at The Children's Hospital of Philadelphia, in collaboration with a number of other research institutions, have identified five new gene regions in young patients with childhood-onset inflammatory bowel disease (IBD).

The five new gene regions were identified during what the researchers call the largest, most comprehensive genetic analysis of childhood IBD to date. The genes were identified on chromosomes 16, 22, 10, 2, and 19. According to the researchers, "the most significant finding was at chromosome locus 16p11, which contains the IL27 gene that carries the code for a cytokine, also called IL27."

"This cytokine acts on a biological pathway, the T-helper 17 pathway, which plays a key role in causing intestinal inflammation," said Hakon Hakonarson, MD, PhD, director of the Center for Applied Genomics at Children's Hospital, and lead author of the research. "There are many cytokines in our immune system, but our research strongly suggests that IL27 has a primary causative role in IBD. This gene discovery makes sense in terms of our functional understanding of the disease."

According to the researchers, many of the previous gene analysis of IBD have focused on the adult disease. Focusing on childhood-onset IBD, the researchers added, allowed them to examine the more severe of the two forms.

The researchers used DNA from more than 3,400 children and adolescents with IBD, as well as nearly 12,000 genetically matched control subjects. The genome-wide association study that was performed used automated genotyping tools to identify gene variants that contributed to the risk of IBD in the young subjects.

Other research centers involved in the study include the Hospital for Sick Children at the University of Toronto; the University of Edinburgh in the UK; Cedars Sinai Medical Center in Los Angeles; Emory University in Atlanta; and the IRCCS-CSS Hospital in S. Giovanni Rotondo, Italy. Results were also published online in Nature Genetics.