| Syndrome | Bilirubin Type | Defect | Key Differentiator(s) |
|---|---|---|---|
| Gilbert | Unconjugated | ↓ UGT1A1 Activity | Benign; jaundice with stress. |
| Crigler-Najjar I | Unconjugated | Absent UGT1A1 | Severe; kernicterus risk; no response to phenobarbital. |
| Crigler-Najjar II | Unconjugated | <20% UGT1A1 | Less severe; responds to phenobarbital. |
| Dubin-Johnson | Conjugated | MRP2 Excretion Defect | Benign; black liver. |
| Rotor | Conjugated | OATP Uptake Defect | Benign; normal liver color. |
