AMINO ACIDS, QUANTITATIVE, URINE
- AMINO ACIDS, QUANTITATIVE, URINE
- Start Date
- Expiration Date
- CPT Codes
- Reference Test
Urine, random (First morning urine preferred)
- Transport Info
- Fasting Required?
- Patient Instructions
Clinical information is needed for appropriate interpretation. Additional required information includes age, gender, diet (eg, TPN therapy), drug therapy, and family history.
Form required: "Patient History for Biochemical Genetics"
- Reference Range
Ion Exchange Chromatography
Common indications for urine amino acid testing include clinical situations such as: 1) acute life-threatening episode, 2) failure to thrive, 3) recurrent vomiting, 4) neurological deterioration, 5) hyperammonemia, 6) lethargy, 7) metabolic acidosis, 8) testing or following therapy for a specific inborn error of metabolism (PKU, MSUD, tyrosinemia, etc.), and 9) kidney stones. Listing of clinical information is particularly important for appropriate interpretation.
In patients with inherited metabolic disorders in whom plasma amino acids are elevated, the same amino acids may be increased in the urine. Plasma amino acid analysis is the preferred test to exclude an inborn error or metabolism. Urine amino acid analysis is indicated in the following cases: to exclude defects of renal amino acid transport, such as cystinuria, lysinuric protein intolerance, Hartnup disease, etc.; as a second tier test for selected inborn errors of metabolism such as HHH (hyperammonemia, hyperornithinemia, homocitrullinuria) syndrome; to evaluate renal tubular function; to investigate the cause of kidney stones.