More than 300,000 people in the UK have IBD, a debilitating disease in which the body’s own immune system attacks parts of the digestive tract. The exact causes of the disease are unclear, and there is currently no cure.
Scientists at Sanger examined the genome of 67,852 people.
They then used three statistical methods to zoom in on variations in the genome which are actively implicated in the disease. Of the regions of the genome associated with IBD they studied, 18 could be pin-pointed to a single genetic variant.
Previous research had analysed the genomes of people with IBD and found hundreds of genetic variants that could be linked. But the researchers had been unable to specify the exact genes involved.
This new research has produced a high-resolution map of the disease. It allows scientists to separate the genetic variants into those that directly influence IBD and those that just happen to be located near each other in the genome.
Dr Jeffrey Barrett, joint lead author from the Wellcome Trust Sanger Institute, says: "We have taken the biggest ever data set for IBD and applied careful statistics to narrow down to the individual genetic variants involved. Now we have a clearer picture of which genes do and do not play a role in the disease. We are zooming in on the genetic culprits of IBD."