Familial cases of primary sclerosing cholangitis or biliary atresia ha
ve been reported, although genetic influences and immunopathological a
bnormalities in these diseases are considered to be obscure. We report
a case of primary sclerosing cholangitis and biliary atresia in sibli
ngs with the observation of HLA-DR antigen expression in the abnormal
bile duct epithelial cells.