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Genetic and Rare Diseases Information Center (GARD)

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N-acetylglutamate synthetase deficiency

Other Names for this Disease
  • Hyperammonemia due to N-Acetylglutamate Synthetase Deficiency
  • N-acetyl glutamate synthetase deficiency
  • NAG synthetase deficiency
  • NAGS deficiency
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Your Question

How is N-acetylglutamate synthase deficiency inherited? Are there any new research studies enrolling people with N-acetylglutamate synthase deficiency? How can I get my loved one seen at the National Institutes of Health?

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

What is N-acetylglutamate synthase deficiency?

N-acetylglutamate synthase deficiency is type of urea cycle disorder. It causes toxic levels of ammonia to accumulate in the blood. Signs and symptoms in newborns may include a lack of energy, unwillingness to eat, seizures, unusual body movements, and poorly controlled breathing or body temperature. Complications may include coma, developmental delay, and learning disability. Some people have a less severe form of the deficiency with earliest symptoms manifesting later in life, particularly following high-protein meals, illness, or other stress. Signs and symptoms may include sudden vomiting, lack of coordination, confusion, and coma. N-acetylglutamate synthase deficiency is caused by mutations in the NAGS gene and is inherited in an autosomal recessive fashion.
Last updated: 12/17/2009

How is N-acetylglutamate synthase deficiency inherited?

N-acetylglutamate synthase deficiency is caused by mutations in the NAGS gene and is inherited in an autosomal recessive fashion. Autosomal recessive inheritance refers to the inheritance pattern in which two mutated copies of the gene that causes a disorder are present in each cell. An affected person usually has unaffected parents who each carry a single copy of the mutated gene (and are referred to as carriers). Autosomal recessive disorders are typically not seen in every generation of an affected family. When two people who are carriers of an autosomal recessive condition have a child, there is a 25% (1 in 4) chance that their child will be affected.[1]

Last updated: 2/19/2010

Are there any new research studies enrolling people with N-acetylglutamate synthase deficiency? How can I get my loved one seen at the National Institutes of Health?

Currently there are clinical trials and research studies enrolling people with N-acetylglutamate synthase deficiency. Instruction on finding these studies are provided below.

The Urea Cycle Disorders Consortium is a team of doctors, nurses, research coordinators, and research labs throughout the US, working together to improve the lives of people with Urea Cycle Disorders. The purpose of this consortium is to provide a way for patients to join with doctors and researchers by participating in research studies. The greater the collaboration between doctors and patients, the more we can learn about Urea Cycle Disorders.To read more about the contact registry, please click on the UCDC link above.

Urea Cycle Disorders Consortium Registry
Children's National Medical Center
Phone: 815-333-4014

Patients are seen at the NIH through participation in clinical trials. Clinical trials are medical research studies in which people participate as volunteers. They are a means of developing new treatments and medications for diseases and conditions. There are strict rules for clinical trials, which are monitored by the National Institutes of Health (NIH) and the U.S. Food and Drug Administration.

Some of the research studies at the NIH Clinical Center involve promising new treatments that may directly benefit patients. The Clinical Center does not charge patients for participation and treatment in clinical studies conducted at the NIH.  In certain emergency circumstances, you may qualify for help with travel and other expenses.

You can search a database of clinical trials being conducted by the NIH at the Clinical Center in Bethesda, Maryland at the following link. You can also contact the Patient Recruitment and Public Liaison Office directly at 1-800-411-1222 to speak with a specialist, who can help you determine if you are eligible for any clinical trials. 

In addition, the NIH through the National Library of Medicine has developed to provide patients, family members, and members of the public with current information on clinical research studies.  You can search this database to find clinical trials at the NIH Clinical Center as well as federally and privately supported trials being conducted at universities and medical centers throughout the United States and around the world. To find clinical trials, click on the link above and use "urea cycle disorders" or "N-acetylglutamate synthase deficiency" as your search term.

When you find a study of interest, review its "eligibility" criteria to determine its appropriateness. Use the study's contact information to learn more. Check these sites often for regular updates.

If you are interested in enrolling your loved one in a clinical trial, you can find helpful general information on clinical trials at the following Web page.

Resources on many charitable or special-fare flights to research and treatment sites and low-cost hospitality accommodations for outpatients and family members, as well as ambulance services, are listed on the Web site of the Office of Rare Diseases (ORD), National Institutes of Health.

In addition, you can find research studies involving N-acetylglutamate synthase deficiency by searching the Research Portfolio Online Reporting Tool (RePORT). RePORT provides access to reports, data, and analyses of research activities at the National Institutes of Health (NIH), including information on NIH expenditures and the results of NIH-supported research.  Although these projects may not conduct studies on humans, you may want to contact the investigators to learn more. To search for studies, click on the link above and enter "urea cycle disorder" or "N-acetylglutamate synthase deficiency" in the “Terms Search” box.  Then click “Submit Query”.

Also, you may be interested in reading more about the following past scientific conference. Click on the conference title to learn more:

The Urea Cycle Disorders Satellite Symposium to the 11th International Congress on Inborn Errors of Metabolism (ICIEM) – Overcoming Barriers – New Developments and Future Directions for Urea Cycle Disorders

Last updated: 2/19/2010