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N-Acetylglutamate Synthetase Deficiency Follow-up

  • Author: Karl S Roth, MD; Chief Editor: Luis O Rohena, MD  more...
Updated: Nov 17, 2014

Further Outpatient Care

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  • The patient should be under the care of a biochemical geneticist (metabolic disease specialist) who is an expert in the care of patients with urea cycle defects.
  • Make medication adjustments on the basis of continued growth and frequently measured plasma amino acids; include the input of a highly trained nutritionist.


See the list below:

  • Consider transferring the patient to a facility equipped for emergent hemodialysis (if the patient is a neonate) and where the appropriate consultants (see Consultations) are immediately available.


See the list below:

  • Possible complications include cerebral edema with resulting brain damage or death.


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  • Long-term prognosis is unclear; most likely, the future intelligence quotient score depends on the severity of the initial presentation and the subsequent hyperammonemic episodes suffered.

Patient Education

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  • Inform parents of their obligate heterozygote status given the likelihood that this is an autosomal recessive trait.
  • Parents must understand that the chance of recurrence is 1:4 (25%) with each subsequent pregnancy.
  • Advise parents to seek early medical attention for the patient in the event of intercurrent illness.
Contributor Information and Disclosures

Karl S Roth, MD Retired Professor and Chair, Department of Pediatrics, Creighton University School of Medicine

Karl S Roth, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Pediatrics, American College of Nutrition, American Pediatric Society, American Society for Nutrition, American Society of Nephrology, Association of American Medical Colleges, Medical Society of Virginia, New York Academy of Sciences, Sigma Xi, Society for Pediatric Research, Southern Society for Pediatric Research

Disclosure: Nothing to disclose.

Specialty Editor Board

Mary L Windle, PharmD Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Nothing to disclose.

Lois J Starr, MD, FAAP Assistant Professor of Pediatrics, Clinical Geneticist, Munroe Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center

Lois J Starr, MD, FAAP is a member of the following medical societies: American Academy of Pediatrics, American College of Medical Genetics and Genomics

Disclosure: Nothing to disclose.

Chief Editor

Luis O Rohena, MD Chief, Medical Genetics, San Antonio Military Medical Center; Assistant Professor of Pediatrics, Uniformed Services University of the Health Sciences, F Edward Hebert School of Medicine; Assistant Professor of Pediatrics, University of Texas Health Science Center at San Antonio

Luis O Rohena, MD is a member of the following medical societies: American Academy of Pediatrics, American Chemical Society, American College of Medical Genetics and Genomics, American Society of Human Genetics

Disclosure: Nothing to disclose.

Additional Contributors

Uri S Alon, MD Director of Bone and Mineral Disorders Clinic and Renal Research Laboratory, Children's Mercy Hospital of Kansas City; Professor, Department of Pediatrics, Division of Pediatric Nephrology, University of Missouri-Kansas City School of Medicine

Uri S Alon, MD is a member of the following medical societies: American Federation for Medical Research

Disclosure: Nothing to disclose.

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Compounds comprising the urea cycle are numbered sequentially, beginning with carbamyl phosphate (1). At this step, the first waste nitrogen is incorporated into the cycle; at this step, N-acetylglutamate exerts its regulatory control on the mediating enzyme, carbamyl phosphate synthetase (CPS). Compound 2 is citrulline, the product of condensation between carbamyl phosphate (1) and ornithine (8); the mediating enzyme is ornithine transcarbamylase. Compound 3 is aspartic acid, which is combined with citrulline to form argininosuccinic acid (ASA) (4); the reaction is mediated by ASA synthetase. Compound 5 is fumaric acid generated in the reaction that converts ASA to arginine (6), which is mediated by ASA lyase.
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