Inherited disorders of intrahepatic cholestasis include entities such as Alagille syndrome, due to mutations in the JAG1 or NOTCH2 genes, progressive familial cholestatic disorders related to mutations in the genes that code for hepatocyte canalicular transporters, bile acid synthetic disorders, and rarer entities such as North American Indian childhood cirrhosis, familial hypercholanemia and Gracile syndrome. Principal distinguishing characteristics of the major inherited disorders of intrahepatic cholestasis are shown in Table 1. Disorders of bilirubin metabolism include Crigler-Najjar, Gilbert, Dubin-Johnson and Rotor syndromes.