Genetic Variant May Lead to New Treatment Options for Inflammatory Bowel Disease

Investigators have identified a genetic variant that doubles the risk of developing ulcerative colitis.

Ulcerative colitis and Crohn’s disease are 2 primary subtypes of inflammatory bowel disease (IBD). Currently, more than 300,000 individuals suffer from IBD in the UK. The exact cause of the disease remains unclear.

In a study published in Nature Genetics, investigators examined the genomes of 16,000 patients with IBD in the UK, as well as 10,000 more patients from a previously published international study. According to the authors, this is the largest whole-genome IBD genetic study to-date.

Through the study, the investigators identified a rare genetic variant that doubles the risk of ulcerative colitis. The results of the study showed that the variant affects the gene ADCY7, which is found in 1 of 200 people in the UK.

It is one of the strongest genetic risk factors associated with ulcerative colitis identified to-date, and could serve as a future drug target for IBD, according to the study.

In the second study, the investigators found that integrin proteins—–which act as bridges for interactions between cells from the immune system and the rest of the body––play a key role in the increased risk of IBD.

The results of the study showed genetic variants that increase the risk of IBD also increase the expression of certain integrins as a response to immune system stimulation.

“We study genetics because we ultimately want to understand the biology of the disease,” said first author Katrina de Lange. “From the genetic information we can extract a compelling story about why a particular anti-integrin drug is effective against inflammatory bowel disease, or why others have serious [adverse events].”

For the next step, the investigators aim to sequence 25,000 genomes of IBD patients in the next 5 years.

“Whilst there are challenges in recruiting large numbers of patients to IBD studies and interpreting the resulting volume of data, there are also great opportunities to better understand the role of genetic variation in not only risk of disease but also in treatment and prognosis,” said co-author Dr Miles Parkes. “The IBD BioResource will drive recruitment of IBD patients across the UK and allow recall of patients for repeat tests so the function of specific genes behind IBD can be explored.”

The authors noted that the study results will be translated into potential treatments by Open Targets, an initiative that uses the outputs of genetic studies and works with pharmaceutical companies to aid new treatment developments for different diseases, including IBD.

“The scale of these collaborations means we are able to spot genetic associations to IBD that we hadn’t seen previously,” said lead author Dr Carl Anderson. “We hope that by continuing to work together we will be able to translate these findings into better treatments for IBD patients.”