ABSTRACT
Identical studies using stable isotopes were performed before and after a 3-day trial of oral N-carbamyl-l-glutamate (NCG) in 5 subjects with late-onset carbamyl phosphate synthetase deficiency. NCG augmented ureagenesis and decreased plasma ammonia in 4 of 5 subjects. There was marked improvement in nitrogen metabolism with long-term NCG administration in 1 subject.
Subject(s)
Carbamoyl-Phosphate Synthase I Deficiency Disease/drug therapy , Glutamates/therapeutic use , Glutamine/blood , Urea/metabolism , Adolescent , Adult , Ammonia/blood , Carbamoyl-Phosphate Synthase I Deficiency Disease/blood , Child , Child, Preschool , Female , Humans , Linear Models , Male , Mass Spectrometry , Treatment Outcome , Young AdultABSTRACT
Very long-chain acyl-CoA dehydrogenase deficiency (VLCADD) can be detected through newborn screening with tandem mass spectrometry. We report a patient who died as a result of severe brain injury due to hypoglycemia. Newborn screening was normal. Postmortem enzyme analysis and molecular testing confirmed the diagnosis of VLCADD.
Subject(s)
Acyl-CoA Dehydrogenase, Long-Chain/deficiency , Neonatal Screening , Tandem Mass Spectrometry , False Negative Reactions , Fatal Outcome , Female , Humans , Hypoglycemia/etiology , Infant , Infant, NewbornABSTRACT
In a patient with N-acetylglutamate synthase (NAGS) deficiency, incorporation of an isotopic label from ammonium chloride into urea was markedly reduced before treatment with N-carbamyl-L-glutamate (NCLG) and completely normalized following treatment. Blood ammonia rose following ammonium tracer ingestion before treatment but remained low following treatment. Serum urea concentration doubled following the treatment.