Crigler-Najjar syndrome type I | Crigler-Najjar syndrome type II | Gilbert syndrome | |
Epidemiology and natural history | |||
Mode of inheritance | Autosomal recessive | Autosomal recessive | Autosomal recessive |
Prevalence | Rare | Rare | Common (approximately 9% of White people are homozygous for a variant TATAA box; 4 to 5% have hyperbilirubinemia) |
Prognosis | Kernicterus, unless vigorously treated | Usually benign, kernicterus occurs rarely | Benign |
Routine clinical evaluation | |||
Serum bilirubin concentration* | 20 to 50 mg/dL (340 to 850 micromol/L) | Usually 8 to 20 mg/dL (136 to 340 micromol/L) | Usually <3 mg/dL (<51 micromol/L) |
Routine liver function tests | Normal | Normal | Normal |
Effect of phenobarbital on serum bilirubin | None | Reduction | Reduction |
Tests not routinely performed | |||
Bilirubin glucuronides¶ | Usually pale; contains small amounts of unconjugated bilirubin | Bilirubin glucuronides present: Increased proportion of bilirubin monoglucuronide | Bilirubin glucuronides present: Increased proportion of bilirubin monoglucuronide |
Liver histology | Normal, but fibrosis is present in approximately 40% of cases[1] | Normal | Normal |
Hepatic bilirubin UGT activity | Absent | Markedly reduced (10% of normal) | Reduced (30% of normal) |
45-minute plasma BSP retentionΔ | Normal | Normal | Usually normal; may be prolonged |
UGT: uridine diphosphate glucuronosyltransferase; BSP: bromosulfophthalein.
* Serum bilirubin concentrations depend on age and optimal medical management. In each of these disorders, further acute elevations may occur, triggered by fasting or intercurrent illnesses. The risk of severe acute exacerbations (eg, bilirubin >20 mg/dL) and resulting kernicterus is high for Crigler-Najjar syndrome type I, low for Crigler-Najjar syndrome type II, and absent for Gilbert syndrome.
¶ Bilirubin glucuronides are measured by high-pressure liquid chromatography of bile collected from the duodenum.
Δ Plasma BSP retention is prolonged in Dubin-Johnson and Rotor syndromes and in hepatobiliary cholestatic disorders.Do you want to add Medilib to your home screen?