Severe Hyperammonemia in Late-Onset Ornithine Transcarbamylase Deficiency Triggered by Steroid Administration

Abstract EN

Ornithine transcarbamylase deficiency (OTCD) is a rare X-linked disorder of urea synthesis leading to hyperammonemia.

Several late-onset cases have been reported.

Undiagnosed and untreated patients are at the risk of death or suffering from irreversible sequelae.

We describe a 56-year-old patient who presented with acute encephalopathy after steroid treatment.

Hyperammonemia due to OTCD was diagnosed and a mutation was found.

This allowed us to diagnose two other family members with unexplained encephalopathy who are now asymptomatic on a low-protein diet.

OTCD should be considered in any patient with hyperammonemic encephalopathy and immediate treatment should be given to avoid a fatal outcome.

We emphasize the need to examine other family members if the diagnosis is confirmed, in order to prevent further life-threatening episodes of encephalopathy or neonatal coma of newborn.