hepatic and biliary disorders
Inborn Metabolic Disorders Causing Hyperbilirubinemia
Dubin Johnson Syndrome and Rotor Syndrome
Dubin-Johnson syndrome and Rotor syndrome cause conjugated hyperbilirubinemia, but without cholestasis, causing no symptoms or sequelae other than jaundice. Bilirubin may appear in the urine, in contrast to the unconjugated hyperbilirubinemia in Gilbert Syndrome (which also causes no other symptoms), in which bilirubin is absent from the urine. Aminotransferase and alkaline phosphatase levels are usually normal. Treatment is unnecessary. This rare autosomal recessive disorder involves impaired excretion of bilirubin glucuronides. It is usually diagnosed by Liver Biopsy ; the liver is deeply pigmented as a result of an intracellular melanin-like substance but is otherwise histologically normal. This rare disorder is clinically similar to Dubin-Johnson syndrome, but the liver is not pigmented, and other subtle metabolic differences are present. 