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Argininosuccinate lyase deficiency

Synonyms
ASA deficiency; ASL deficiency; Arginino succinase deficiency; Argininosuccinate acidemia; Argininosuccinic Aciduria; Argininosuccinic acid lyase deficiency; Inborn error of urea synthesis, arginino succinic type; Urea cycle disorder, arginino succinase type
Modes of inheritance
Autosomal recessive inheritance (Orphanet)

Summary

Excerpted from the GeneReview: Argininosuccinate Lyase Deficiency
Deficiency of argininosuccinate lyase (ASL), the enzyme that cleaves argininosuccinic acid to produce arginine and fumarate in the fourth step of the urea cycle, may present as a severe neonatal-onset form or a late-onset form: The severe neonatal-onset form is characterized by hyperammonemia within the first few days after birth that can manifest as increasing lethargy, somnolence, refusal to feed, vomiting, tachypnea, and respiratory alkalosis. Absence of treatment leads to worsening lethargy, seizures, coma, and even death. In contrast, the manifestations of late-onset form range from episodic hyperammonemia triggered by acute infection or stress to cognitive impairment, behavioral abnormalities, and/or learning disabilities in the absence of any documented episodes of hyperammonemia. Manifestations of ASL deficiency that appear to be unrelated to the severity or duration of hyperammonemic episodes: Neurocognitive deficiencies (attention-deficit/hyperactivity disorder, developmental delay, seizures, and learning disability). Liver disease (hepatitis, cirrhosis). Trichorrhexis nodosa (coarse brittle hair that breaks easily). Systemic hypertension.
Full text of GeneReview (by section):
Summary
Diagnosis
Clinical Characteristics
Genetically Related (Allelic) Disorders
Differential Diagnosis
Management
Genetic Counseling
Resources
Molecular Genetics
Chapter Notes
References
Authors:
Sandesh C Sreenath Nagamani
Ayelet Erez
Brendan Lee
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Available tests

82 tests are in the database for this condition.

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Clinical tests (82 available)

Biochemical Genetics Tests

Molecular Genetics Tests

Genes See tests for all associated and related genes

  • Also known as: ASAL, ASL
    Summary: argininosuccinate lyase

Clinical features

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Imported from Human Phenotype Ontology (HPO)

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Reviews

Clinical resources

Practice guidelines

  • ACMG, ACT Sheet, 2022
    American College of Medical Genetics and Genomics, Newborn Screening ACT Sheet, [Elevated Citrulline], Amino Acidemia/Urea Cycle Disorder, 2022
  • ACMG Algorithm, 2022
    American College of Medical Genetics and Genomics, Elevated Citrulline: Amino Acidemia Algorithm, 2022
  • ACMG ACT, 2012
    American College of Medical Genetics and Genomics, Transition to Adult Health Care ACT Sheet, Argininosuccinic Acidemia, [Urea Cycle Disorder], 2012

Molecular resources

Consumer resources

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