Case 2
The patient was the first son of unrelated Dutch parents, born at 41 weeks of gestation. At day 4, he had a remarkable tachypnea and lethargy that prompted blood gas analysis. The results showed a respiratory alkalosis (pH 7.6, CO2 2.5 kPa) and elevated ammonia concentration (270-309 µmol/L). Physical examination revealed no additional abnormalities. A urea cycle defect was suspected; therefore, the patient was referred to a metabolic center and treated with sodium benzoate, an ammonia scavenger medication, dietary protein restriction and later with NCG. Cerebral ultrasound was normal with no signs of edema or intracranial bleeding.
Metabolic investigations revealed highly elevated plasma glutamine (1018 µmol/L, normal 208-294) and low-to-normal plasma citrulline whereas the excretion of orotic acid was normal. This led to the probable diagnosis of NAGSD. Treatment with protein restriction, citrulline supplementation and NCG resulted in normal metabolic profile and clinical condition.
The child developed normally except for an impaired vision due to Leber congenital amaurosis. At present, 7 years old, he attends regular school with the necessary adaptations because of his blindness. His growth is unremarkable. His diet is normal and with adequate NCG medication his amino acid profile is normal.