Early care of N-acetyl glutamate synthase (NAGS) deficiency in three infants from an inbred family

N-acetyl glutamate synthase (NAGS) deficiency is the rarest urea cycle defect presenting as neonatal onset life-threatening hyperammonemia. We report here a family history of severe NAGS deficiency: after the index-case with severe hyperammonemia, one patient benefited from antenatal diagnosis, and from primary care at birth, another one was diagnosed at 2-days and immediately treated with carbaglumic-acid. Finally, we report excellent tolerance to long-term carbaglumic-acid treatment, with no side effects, and healthy neurological and psychomotor development.