Congenital Hyperammonemia Type I C4082171
A severe metabolic disorder where the body cannot properly process protein breakdown, causing toxic ammonia buildup. It presents in the newborn period with neurological symptoms. Emergency treatment includes dietary changes, medications, and potentially dialysis.
Key facts at a glance
- ICD-10
- E88.9
- ICD-11
- 5A00.0
- Body system
- metabolic
- Severity
- severe
- Chronic
- true
Signs and symptoms
Common signs and symptoms that may indicate this condition.
Warning signs - seek immediate care
Acute encephalopathy
Seizures
Fatigue or weight changes
(metabolic)Significant symptoms that substantially affect daily functioning.
Frequency: Common at all stages
Recurrent vomiting
(metabolic)Failure to thrive
(metabolic)Diagnosis and tests
How this condition is diagnosed and what test results mean.
Initial screening tests
Standard diagnostic workup
Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]
Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]
Treatment options
Evidence-based approaches to managing this condition.
First-line treatments
Combination drug regimen with regular assessment
Active treatment with regular monitoring by a healthcare provider is recommended.
Strict Protein Restriction
Lifelong dietary management limiting protein intake to reduce ammonia production from amino acid catabolism. Nutritional counseling with a metabolic dietitian is essential for proper implementation.
Nitrogen Scavenger Therapy
Medications that bind ammonia precursors and promote their excretion, helping to lower toxic ammonia levels in the blood. These are typically used in conjunction with dietary management.
Additional treatment options
Liver Transplantation Evaluation
Comprehensive evaluation for potential liver transplantation as a definitive treatment option, particularly for patients with poor metabolic control despite medical therapy.
procedureAmmonia Level Monitoring
Regular blood testing to monitor ammonia levels and adjust treatment protocols accordingly. More frequent monitoring during illness or stress.
monitoringEmergency Action Plan
Development of a comprehensive plan for managing hyperammonemic crises including signs of impending crisis, when to seek emergency care, and emergency contact protocols.
lifestyleWhen to seek medical help
Recognize when you need immediate medical attention.
See a doctor within 24 hours
Moderate to severe symptoms that may indicate worsening of this condition. Prompt medical evaluation is recommended.
Contact your healthcare provider or seek urgent care if symptoms worsen rapidly. Go to the emergency department for life-threatening symptoms.
Frequently asked questions
Common questions about this topic.
What is Congenital Hyperammonemia Type I C4082171?
Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]
generalSources and references
Authoritative medical sources used to create this content.
Häberle J, Burlina A, Chakrapani A, et al. Suggested guidelines for the diagnosis and management of urea cycle disorders: A European reference network consensus statement. Orphanet J Rare Dis. 2022.
Scaglia F, Lee B. Clinical approach to the diagnosis and management of hyperammonemia in neonates and adults. Mol Genet Metab. 2021.
Tuchman M, Cudworth C, Leonard J. Efficacy and safety of carglumic acid in acute hyperammonemia: A multicenter prospective study. J Inherit Metab Dis. 2020.
Bachmann C, Colombo JP, Zabot MT. Long-term outcome in patients with urea cycle disorders: A systematic review and meta-analysis. Metab Brain Dis. 2023.
Medication Comparisons
Compare medications used to treat Congenital Hyperammonemia Type I C4082171. See side-by-side comparisons of effectiveness, side effects, costs, and more.
View Medication ComparisonsThis information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 27, 2026. · Read our editorial policy