title: Crigler-Najjar Type 1 syndrome: absence of hepatic bilirubin UDP-glucuronyl transferase activity and therapeutic responses to light.
abstract: A 16-year-old boy with severe congenital unconjugated hyperbilirubinaemia is described in whom mental retardation occurred as an isolated neurological deficit. The diagnosis of Crigler-Najjar type 1 syndrome was supported by an extreme and persistent elevation of  serum unconjugated bilirubin (650 mumol/l), failure of administered phenobarbitone to lower serum bilirubin concentration and family history of a similarly affected sibling. Hepatic bilirubin UDP-glucuronyl transferase activity determined in vitro by a sensitive new enzyme assay was found to be absent using bilirubin or bilirubin monoglucuronide as substrate. Phototherapy for 12 hours each night produced a partial but highly significant reduction in serum bilirubin concentration, which was not influenced further by the administration of cholestyramine.
mesh_terms: D000293:Adolescent; D001663:Bilirubin / Q000378:metabolism; D003414:Crigler-Najjar Syndrome / Q000201:enzymology* / Q000473:pathology / Q000628:therapy; D014453:Glucuronosyltransferase / Q000172:deficiency; D006801:Humans; D006933:Hyperbilirubinemia, Hereditary / Q000201:enzymology*; D008099:Liver / Q000201:enzymology / Q000473:pathology; D008297:Male; D010789:Phototherapy
chemical_list: D014453:Glucuronosyltransferase; D001663:Bilirubin