Researchers announce new genetic discoveries about Primary Sclerosing Cholangitis

Posted on: 21st December 2016

A large-scale study has led researchers to identify four previously unknown genetic risk locations for Primary Sclerosing Cholangitis (PSC).

Featured in Nature Genetics this is the largest genome-wide association study of PSC to date, and a step toward providing breakthrough treatments for the unmet needs of PSC patients.

It was led by Konstantinos Lazaridis, M.D. from the Mayo Clinic, and Carl Anderson, Ph.D., of the Wellcome Trust Sanger Institute, along with collaborators from six other U.S. medical centres, co-investigators from the U.K., Germany and Norway and collaborators from other European countries.

PSC is an uncommon chronic liver disease, affecting around 1 in 10,000 individuals, in which the bile ducts inside and outside the liver progressively decrease in size due to inflammation and scarring (fibrosis). The disease may occur alone, but frequently is associated with inflammatory bowel disease (IBD), especially chronic ulcerative colitis. About 75 percent of sufferers develop inflammatory bowel disease (IBD), although only 5 to 7 percent of those affected by pre-existing IBD alone later develop PSC.

Researchers compared the genetic information of 4,796 PSC patients against a control population of nearly 20,000 individuals, the specimens of which were provided by patients from the U.S. and Europe, including healthy controls from Mayo Clinic Biobank.

Using the data, they identified four new markers of PSC risk on the human genome, bringing the total number of known predisposing locations to 20.

The study also allowed for clearer estimations as to how PSC and IBD may share genetic risk factors.

Dr. Lazaridis said: "The immense scale of this genetic study allowed us to analyse, for the first time, the complex genetic relationship between Primary Sclerosing Cholangitis and IBD.

 "Additional scientific efforts for genome sequencing of Primary Sclerosing Cholangitis patients will give us more opportunities to find the specific genetic underpinnings that contribute to the risk of Primary Sclerosing Cholangitis and to explain what makes the correlation between Primary Sclerosing Cholangitis and IBD. Such knowledge will be important in facilitating the development of medical therapies for Primary Sclerosing Cholangitis - an urgent need for patients.”

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