Coma query cause.

A 54-year-old woman with coeliac disease was admitted to hospital electively for supplemental nutrition. Shortly after feeding started she deteriorated into a hyperammonemic coma with refeeding syndrome, requiring an extensive intensive care admission. Urea cycle disorders were investigated and a biochemical diagnosis of ornithine transcarbamylase deficiency was made. This is a rare diagnosis in the adult population. This case report summarises protein metabolism, urea cycle disorders and the challenges of management.