Cholestasis in Crigler–Najjar Syndrome Type I: An Uncommon Histopathological Finding in a Rare Disorder

Abstract Crigler–Najjar syndrome is a rare autosomal recessive disorder characterized by severe unconjugated hyperbilirubinemia. Liver histopathology in Crigler–Najjar Syndrome typically reveals fibrosis, while features of cholestasis are rarely reported. We describe an 8-month-old male infant with persistent unconjugated hyperbilirubinemia, global developmental delay, and spasticity. Liver biopsy demonstrated canalicular bile plugs and focal bile duct proliferation, suggestive of cholestasis – a rare finding in Crigler–Najjar Syndrome. Despite initial diagnostic uncertainty due to this atypical presentation, genetic testing confirmed a homozygous mutation in the uridine diphosphate-glucuronosyltransferase 1A1 gene consistent with Crigler–Najjar Syndrome Type I.