Crigler-Najjar syndrome

This code represents Crigler-Najjar syndrome, a rare, inherited disorder characterized by severe unconjugated hyperbilirubinemia due to a deficiency or absence of the enzyme UDP-glucuronosyltransferase (UGT1A1). This enzyme is crucial for conjugating bilirubin in the liver, leading to its accumulation and potential neurotoxicity, particularly kernicterus.

Use this code for patients diagnosed with Crigler-Najjar syndrome, either Type I (complete absence of UGT1A1 activity) or Type II (partial deficiency). Documentation should clearly indicate the diagnosis of Crigler-Najjar syndrome, often supported by genetic testing results or clinical presentation of severe unconjugated hyperbilirubinemia unresponsive to conventional treatments.

• Differentiate between Type I and Type II if specified in the documentation, although both fall under this single code.
• Do not confuse with other causes of unconjugated hyperbilirubinemia, such as Gilbert's syndrome (E80.4) or neonatal jaundice (P55-P59).
• Code any associated neurological complications, such as kernicterus (P57.-), as secondary diagnoses.