Crigler-Najjar Syndrome (Type 1) - A Case Report and Review of Literature.

Crigler-Najjar syndrome (CNN) type I is a rare autosomal recessive disorder caused by complete deficiency of uridine 5'-diphosphate glucuronosyltransferase 1A1, leading to severe unconjugated hyperbilirubinemia and a high risk of kernicterus. We describe the case of a 7-year-old girl with CNN type I and kernicterus who presented with fever and breakthrough seizures during an upper respiratory infection, with severe neurodevelopmental impairment, including spastic quadriplegic cerebral palsy, epilepsy, global developmental delay, and failure to thrive. This case highlights the devastating, irreversible neurological sequelae of untreated neonatal hyperbilirubinemia and emphasizes the importance of early diagnosis and aggressive management.