Lien J, Nyhan WL, Barshop BA.
University of California–San Diego, La Jolla, CA, USA.
Arch Neurol 2007;64:1777–9.
Editor’s note: Disorders of fatty acid oxidation, the organic acidemias, and urea cycle defects can all cause a severe hyperammonemic encephalopathy. Ornithine transcarbamylase (OTC) deficiency is the most common form of urea cycle disorder, and usually presents as hyperammonemia, encephalopathy, and seizures in the neonatal period.