A case of adult-onset type II citrullinemia induced by hospital diet.

Abstract

A 47-year-old Japanese man was first admitted to our hospital for 8days because of an asthma attack. After discharge he changed his diet. On the 12th day after his discharge, he was re-admitted to our hospital because he exhibited transient loss of consciousness with flapping tremor. His plasma ammonia level was extremely high (245μg/dL; normal, <90μg/dL), suggesting hepatic encephalopathy. He underwent intravenous administration of branched-chain amino acids (Aminoleban(®)) and oral administration of lactulose and kanamycin sulfate; however, the hyperammonemia did not improve. Analysis of the amino acids and citrin gene led to the diagnosis of adult-onset type II citrullinemia (CTLN2). Following this diagnosis, the carbohydrate content of his diet was mildly restricted. As a result, his plasma ammonia level markedly improved (ammonia, 40-60μg/dL) and he became symptom-free without any medication. CTLN2 is a metabolic disorder characterized by increased plasma concentrations of citrulline and ammonia, which occurs by the failure of compensatory mechanisms associated with diet. Here, we report a case of a patient for whom a change in eating habits during his hospitalization disturbed his compensatory mechanism resulting in clinical CTLN2, which was reversed with an appropriate diet.