National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

N-acetylglutamate synthase deficiency



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?


What is N-acetylglutamate synthase deficiency?

N-acetylglutamate synthase deficiency (NAGS) is type of metabolic disorder that affects the processing of proteins and removal of ammonia from the body. When proteins are processed by the body, ammonia is formed. Individuals with NAGS are not able to remove ammonia from the body and have symptoms due to toxic levels of ammonia that build up in the blood. NAGS and other similar disorders are a type of metabolic condition known as a urea cycle disorder.[1][2] 

Signs and symptoms in newborns with NAGS 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. NAGS is caused by mutations in the NAGS gene and is inherited in an autosomal recessive fashion. Treatment may include maintaining a low protein diet and using medications that provide alternative routes to remove ammonia from the body.[1][3]
Last updated: 4/12/2017

How is N-acetylglutamate synthase deficiency (NAGS) inherited?

NAGS is caused by mutations in the NAGS gene and is inherited in an autosomal recessive manner.[1] This means that to be affected, a person must have a mutation in both copies of the responsible gene in each cell. Affected people inherit one mutated copy of the gene from each parent, who is referred to as a carrier. Carriers of an autosomal recessive condition typically do not have any signs or symptoms (they are unaffected). When 2 carriers of an autosomal recessive condition have children, each child has a:
  • 25% chance to be affected
  • 50% chance to be an unaffected carrier like each parent
  • 25% chance to be unaffected and not a carrier
Last updated: 4/12/2017

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

 

There may be clinical trials and research studies enrolling people with NAGS. Instructions 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
Email: jseminar@cnmc.org

Patients are typically 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.
http://clinicalstudies.info.nih.gov/ 

In addition, the NIH through the National Library of Medicine has developed ClinicalTrials.gov 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 ClinicalTrials.gov Web page.
http://clinicaltrials.gov/ct2/info/understand

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.
http://rarediseases.info.nih.gov/Resources.aspx?PageID=8

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”.

Last updated: 4/12/2017

We hope this information is helpful. We strongly recommend you discuss this information with your doctor. If you still have questions, please contact us.

Warm regards,
GARD Information Specialist

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  1. N-acetylglutamate synthase deficiency. Genetics Home Reference. October 2006; http://ghr.nlm.nih.gov/condition=nacetylglutamatesynthasedeficiency.
  2. What is a Urea Cycle Disorder?. National Urea Cyle Disorders Foundation. http://www.nucdf.org/ucd.htm. Accessed 4/12/2017.
  3. Mew NA, Lanpher BC, Gropman A, Chapman KA, Simpson KL, Summar ML. Urea Cycle Disorders Overview. GeneReviews. April 9, 2015; http://www.ncbi.nlm.nih.gov/books/NBK1217/.