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-min plasma BSP retentionΔ | Normal | Normal | Usually normal; may be prolonged |