Amongst the findings are loci containing genes known to be implicated in a number of other common diseases including diabetes, rheumatoid arthritis and psoriasis. However, the genetic relationship between Crohn's and these other diseases is not always straightforward. For example, the genetic variant PTPN2 appears to increase susceptibility to both Crohn's disease and type 1 diabetes. But the similarly named PTPN22 increases the risk of developing type 1 diabetes, yet appears to offer protection from Crohn's.
Although some of the disease connections were unsurprising there is already a known epidemiological correlation between Crohn's disease and psoriasis, for example the ORMDL3 gene on chromosome 17 provided the most unexpected link. ORMDL3 was already known to be a genetic risk factor for childhood asthma, but until now, no epidemiological link had ever been seen between asthma and Crohn's disease.
"It's too early for us to say how Crohn's disease and many of these other diseases, including asthma, are linked at a biological level," says Dr Miles Parkes, Consultant Gastroenterologist at Addenbrooke's Hospital and the University of Cambridge, who also worked on the study. "However, we are building up a picture of the biology underlying Crohn's disease, and the more we understand about the underlying biology of these diseases, the better equipped we will be to treat them.
"Studies such as this are not about developing diagnostic tests, but about identifying targe
|Contact: Craig Brierley|