Health Professionals Guide to Newborn Screening

Argininosuccinic Acidemia (ASA)

NOTE: Newborn Screening can not differentiate ASA from Citrullinemia
 
Autosomal recessive urea cycle disorder caused primarily by a deficiency in argininosuccinic acid (ASA) lyase enzyme activity causing the build up of argininosuccinic acid, citrulline, and ammonia in the blood. Clinical symptoms include lack of appetite, vomiting, listlessness, seizures, and coma.

Prevalence (WI):	1:250,000
Analyte Measured:	Citrulline
Abnormal Levels:	³ 85 µmol/L
Feeding Effect:	None
Timing Effect:	< 24 hours of age: Repeat at two weeks ³ 24 hours of age: Results are valid
Confirmation:	Immediate consult with a metabolic specialist at a metabolic treatment center.
Treatment:	The treatment for ASA includes a high-calorie, protein restricted diet; arginine supplementation, and administration of sodium benzoate and sodium phenylacetate. Dialysis may be necessary in some affected individuals.

Information on treatment centers is also available on this site.

For information about other screened disorders, click on the next page button, or follow one of these links:

• Argininosuccinic Acidemia (ASA)	• Hemoglobin Variants
• Biotinidase Deficiency	• Homocystinuria
• Congenital Adrenal Hyperplasia	• Hypermethioninemia
• Congenital Hypothyroidism	• Hyperphenyalaninemia
• Citrullinemia (Types I & II)	• Maple Syrup Urine Disease
• Cystic Fibrosis	• Organic Acidemias (14)
• Fatty Acid Oxidation Disorders (12)	• Phenylketonuria (Includes Biopterin Cofactor defects of regeneration and biosynthesis)
• Galactosemia	• Severe Combined Immune Deficiency (SCID)
• Hemoglobin S-Beta Thallassemia	• Sickle Cell Disease
• Hemoglobin S/C Disease	• Tyrosinemia (Types I,II, & III)

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