Exome sequencing in patient‐parent trios suggests new candidate genes for early‐onset primary sclerosing cholangitis

BACKGROUND & AIMS Primary sclerosing cholangitis (PSC) is a rare bile duct disease strongly associated with inflammatory bowel disease (IBD). Whole‐exome sequencing (WES) has contributed to understanding the molecular basis of very early‐onset IBD, but rare protein‐altering genetic variants have not been identified for early‐onset PSC. We performed WES in patients diagnosed with PSC ≤ 12 years to investigate the contribution of rare genetic variants to early‐onset PSC. METHODS In this multicentre study, WES was performed on 87 DNA samples from 29 patient‐parent trios with early‐onset PSC. We selected rare (minor allele frequency