N-Acetylglutamate Synthase Deficiency (NAGS)

N-acetylglutamate synthase (NAGS) deficiency is an inborn error of the urea cycle. Onset may occur from the neonatal period to adulthood. The presentation ranges from early neonatal hyperammonemia with failure to feed, inability to maintain body temperature and drowsiness, to late onset hyperammonemia that may result in chronic gastrointestinal, neurological or psychiatric signs, sometimes triggered by infections or other stress. These symptoms can lead to coma and death in the most severe cases. Approximately half of reported cases have presented in the neonatal period. NAGS deficiency is clinically and biochemically indistinguishable from carbamylphosphate synthetase I (CPSI) deficiency. General treatments for NAGS deficiency are protein restriction, hypercaloric infusion and arginine supplementation, if needed. Hyperammonemia in NAGS deficiency may be effectively treated with N-carbamylglutamate.

Tests Available

Forms and Documents

Test Details

  • Confirmation of biochemical diagnosis
  • Differentiation between NAGS deficiency and CPS1 deficiency
  • Carrier testing
  • Prenatal diagnosis in at risk pregnancies
  • Capillary Sequencing

Ordering

478
4-5 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL) | Buccal Swabs

Billing

81479x1
No
Yes
  • 270.6 Disorders of urea cycle metabolism, Argininosuccinic aciduria, Citrullinemia, Disorders of metabolism of ornithine, citrulline, argininosuccinic acid, arginine, and ammonia, Hyperammonemia, Hyperornithinemia
* For price inquiries please email zebras@genedx.com

References

  1. Caldovic et al. (2007) Human Mutation 28 (8):754-9 (PMID: 17421020)
  2. Sancho-Vaello et al. (2016) Hum. Mutat. 37 (7):679-94 (PMID: 27037498)
  3. Stenson et al. (2014) Human Genetics 133 (1):1-9 (PMID: 24077912)
  4. Heibel et al. (2011) Hum. Mutat. 32 (10):1153-60 (PMID: 21681857)