hyperammonemia due to N-acetylglutamate synthase deficiency
Findings
No curated finding names hyperammonemia due to N-acetylglutamate synthase deficiency yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
N-acetylglutamate synthase (NAGS) deficiency is a urea cycle disorder leading to hyperammonaemia.
Definition from the Mondo Disease Ontology (MONDO:0009377), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal recessive inheritance
- Onset and course
- Neonatal onset
HPO, annotations 2026-09-02
Features
51 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- HyperammonemiaHPOHP:0001987
- 3 of 3 reported patients
- Very frequent (80% to 99% of cases)
- HyperglutamatemiaHPOHP:0500149
- 2 of 2 reported patients
- HyperglutaminemiaHPOHP:0003217
- 3 of 3 reported patients
- Occasional (5% to 29% of cases)
- LethargyHPOHP:0001254
- 3 of 3 reported patients
- Occasional (5% to 29% of cases)
- Reduced hepatic N-acetylglutamate synthase activityHPOHP:6000161
- 1 of 1 reported patient
- Respiratory distressHPOHP:0002098
- 3 of 3 reported patients
- Very rare (1% to 4% of cases)
Show the remaining 39
- Acute hyperammonemiaHPOHP:0008281
- Occasional (5% to 29% of cases)
- AgitationHPOHP:0000713
- Occasional (5% to 29% of cases)
- AnxietyHPOHP:0000739
- Occasional (5% to 29% of cases)
- Cognitive impairmentHPOHP:0100543
- Occasional (5% to 29% of cases)
- ConfusionHPOHP:0001289
- Occasional (5% to 29% of cases)
- DrowsinessHPOHP:0002329
- Occasional (5% to 29% of cases)
Genes
1 gene
Germline variants in the gene encoding each protein, as classified by GenCC submitters, each in their own words. Limited, disputed and refuted submissions are listed too.
- NAGSHGNC:17996
- Definitive · ClinGen · Autosomal recessive · 2019
- Definitive · G2P · Autosomal recessive · 2015
- Definitive · Natera · Autosomal recessive · 2023
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2020
- Strong · PanelApp Australia · Autosomal recessive · 2025
- Supportive · Orphanet · Autosomal recessive · 2021
Where it sits
Other names
1 name
Resolves to: hyperammonemia due to N-acetylglutamate synthase deficiency
- Also called
- NAGS deficiency