Internal Medicine

0521779407-C04 CUNY1086/Karliner 0 521 77940 7 June 14, 2007 20:37

418 Crigler-Najjer Syndrome Type 1

tests

Basic Tests

■plasma bilirubin from 17–50 mg/dL, all unconjugated and usually

>20mg/dL

■normal liver enzymes and hemolytic screen

Special Diagnostic Tests

■phenobarbital therapy fails to decrease bilirubin

■gene probes abnormal: mutations in the gene that encodes UGT1A1

resulting in absent enzyme activity

■liver biopsy: tissue enzyme assay of UGT1A1 shows no activity

■Other Diagnostic

■oral cholecystogram: normal

■liver biopsy: histology normal

differential diagnosis

■sepsis

■hemolysis

■Crigler-Najjer syndrome type 2 and Gilbert’s respond to phenobar-

bital therapy

management

■monitor bilirubin, hydration, and neurologic exam

■avoid bilirubin-displacing drugs

■phenobarbital trial: 5 mg/kg/day orally

specific therapy

■phototherapy: basic treatment for >10 hr/d keeping total bilirubin

<20 mg/dL (normal birth weight infants) and <35–45 mg/dL (older

patients) for kernicterus prevention

Other Specific Therapies

■double-volume exchange transfusion (infants)

■plasmapheresis (older patients)

■liver transplantation

■tin mesoporphyrin inhibits heme oxygenase and decreases bilirubin

production (experimental); complications of cutaneous photosen-

sitivity and iron deficiency anemia

■oral agents to decrease enterohepatic circulation of bilirubin:

cholestyramine, agar, calcium carbonate and phosphate