A Case Report of Crigler-Najjar Syndrome Type I and Schizophrenia: Exploring the Intersection of Rare Metabolic and Psychiatric Disorders.

Crigler-Najjar syndrome type I (CN-I) is a rare autosomal recessive disorder caused by mutations in the UGT1A1 gene, leading to a deficiency of bilirubin-UDP-glucuronosyltransferase and resulting in severe unconjugated hyperbilirubinemia. Unconjugated bilirubin accumulation can cause neurotoxic effects and has been implicated in oxidative stress within the brain, potentially influencing neuropsychiatric disorders such as schizophrenia. We present the case of a 38-year-old male diagnosed with CN-I at birth after presenting with neonatal jaundice and subsequent kernicterus. Despite normal early development, he experienced progressive deterioration in speech, gait, and cognitive abilities. At age 13, he underwent a partial liver transplant. Several years post-transplant, he developed schizophrenia, exhibiting hallucinations, persecutory delusions, irritability, and behavioral disturbances, resulting in multiple psychiatric admissions and ongoing treatment with paliperidone and olanzapine. Family history revealed a brother with Crigler-Najjar syndrome type II and parental consanguinity. This case suggests that bilirubin dysregulation in CN-I may contribute to schizophrenia via oxidative stress and neurotoxicity in brain regions critical for cognitive and motor functions, and that post-liver transplantation metabolic changes may further influence psychopathology. It underscores the need to consider metabolic disorders in the pathogenesis of psychiatric illness and supports a potential role for bilirubin in schizophrenia. Further research is warranted to explore the pathophysiological connections between metabolic disorders and neuropsychiatric manifestations.