citrin deficiency (Monarch Disease Ontology term MONDO_0016602) is a rare autosomal recessive urea cycle defect characterized clinically by recurring episodes of hyperammonemia and associated neuropsychiatric symptoms in the adult-onset form (citrullinemia type II), and by transient cholestasis and variable hepatic dysfunction in the neonatal form (neonatal intrahepatic cholestasis due to citrin deficiency).