This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.
|Medical Terms||Other Names||
|30%-79% of people have these symptoms|
Decreased muscle tone in infant
|5%-29% of people have these symptoms|
Excessive, persistent worry and fear
Abnormality of cognition
Mental impairment[ more ]
|Failure to thrive||
Weight faltering[ more ]
Tiredness[ more ]
Poor feeding[ more ]
Increased blood alanine
Increased serum alanine[ more ]
High plasma glutamine
Difficulty staying or falling asleep
|Loss of consciousness||
|1%-4% of people have these symptoms|
Disruption of blood oxygen supply to brain
Echoing another person's speech
Abnormally small skull
Decreased circumference of cranium
Decreased size of skull
Reduced head circumference
Small head circumference[ more ]
Peripheral nerve disease
Difficulty breathing[ more ]
Repetitive or self-injurious behavior[ more ]
|Percent of people who have these symptoms is not available through HPO|
Aggressiveness[ more ]
Mental disorientation[ more ]
High blood ammonia levels
|Increased level of L-glutamic acid in blood||0410068|
Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.
The resources below provide information about treatment options for this condition. If you have questions about which treatment is right for you, talk to your healthcare professional.
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If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.
If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.
You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.
Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.
Conditions with similar signs and symptoms from Orphanet
The principle differential diagnosis is carbamoylphosphate synthetase deficiency (see this term).
Visit the Orphanet disease page for more information.
Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.
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 Urea Cycle Disorders Consortium maintains a registry for patients who wish to be contacted about clinical research opportunities.
For more information on the registry see: http://rarediseasesnetwork.epi.usf.edu/ucdc/takeaction/index.htm
Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.
Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare disease.
These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.
Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new 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? See answer