Coma, hyperammonemia, metabolic acidosis, and mutation: lessons learned in the acute management of late onset urea cycle disorders.

Urea cycle disorders are an important and treatable cause of hyperammonemia in the newborn and pediatric age group. Presentation in adolescence or adult life is rare and can manifest as frequent vomiting and behavioral changes. An inherited metabolic disorder should be considered in adults with obvious or occult encephalopathy. Failure to diagnose and treat rapidly may lead to irreversible neuronal damage. An improved understanding of the diagnosis and management of late-onset urea cycle disorders is needed to assist nephrologists in providing optimal care. This report describes the clinical characteristics of a young man with first presentation of hyperammonemia in adult life.