Inborn errors of biliary canalicular transport systems.

Cholestatic syndromes are inborn or acquired disorders of bile formation. In recent years, several inherited cholestatic syndromes were characterized at the molecular level: progressive familial intrahepatic cholestasis (PFIC) and benign recurrent intrahepatic cholestasis (BRIC). Both PFIC and BRIC were divided phenotypically in distinct subtypes; however, at the genotype level, these clinical entities overlap. PFIC starts in early childhood and progresses toward liver cirrhosis, which often requires liver transplantation within the first decade of life. The diagnosis of PFIC is usually made on the basis of clinical and laboratory findings but needs to be confirmed by genetic and histological analysis. Only recently was it recognized that BRIC, which was estimated as a milder form of PFIC-1, may be caused by more than one gene.