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Start free with EleplanArgininosuccinic aciduria
ORPHA:23Disease
Also called ASA deficiency · ASL deficiency · Argininosuccinase deficiency · Argininosuccinatelyase deficiency · Argininosuccinic acid lyase deficiency
What it is
A rare, genetic disorder of urea cycle metabolism typically characterized by either a severe, neonatal-onset form that manifests with hyperammonemia accompanied with vomiting, hypothermia, lethargy and poor feeding in the first few days of life, or late-onset forms that manifest with stress- or infection-induced episodic hyperammonemia or, in some, behavioral abnormalities and/or learning disabilities, or chronic liver disease. Patients often manifest liver dysfunction.
Key facts
- Prevalence
- 1-9 / 100 000 (Europe)
- Age of onset
- All ages
- Inheritance
- Autosomal recessive
- Classified as
- Disease
Prevalence figures describe populations, not individuals, and are often estimates from a single study. Where the figure is an incidence or a birth prevalence, it says so.
Signs and symptoms
Common30–79%
18- Argininosuccinic aciduria
- Ataxia
- Drowsiness
- EEG abnormality
- Elevated circulating hepatic transaminase concentration
- Elevated plasma citrulline
- Hepatomegaly
- Hypertension
- Increased circulating argininosuccinic acid
- Intellectual disability
- Lethargy
- Monilethrix
- Neurodevelopmental delay
- Respiratory alkalosis
- Seizure
- Specific learning disability
- Tachypnea
- Vomiting
Sometimes5–29%
28- Abnormal hair quantity
- Arrhythmia
- Attention deficit hyperactivity disorder
- Carious teeth
- Chronic pancreatitis
- Cirrhosis
- Delayed speech and language development
- Diarrhea
and 20 more in this range
These ranges are how often a sign appears across everyone diagnosed, not a prediction for one person — most people have some of these and not others. Orphanet also records findings that are specifically absent in this disease; those are in the data but not listed here.
Gene
ICD-10 codes
ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.
Related health topics
Reached through the ICD-10 categories this disease is filed under, so these describe the broader group rather than this disease specifically.
Cross-references
Orphadata Science: Free access data from Orphanet. © INSERM 1999. Data version 2026-06-23. Available under CC BY 4.0. This is a reference, not medical advice.
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