Amino Acid Full Panel

Test Description:

Plasma amino acid analysis is indicated when following up infants with a positive newborn screening result, evaluating patients with symptoms of a possible metabolic condition (such as lethargy, vomiting, and failure to thrive) and monitoring individuals diagnosed with a metabolic condition. Quantitative ion exchange chromatography is used to provide a full panel of 30-40 amino acid levels in plasma. Plasma amino acid values are reported as micromole/liter and compared to age-matched normal values. This assay is sensitive in detecting specific amino acid disorders such as phenylketonuria (PKU), maple syrup urine disease (MSUD), urea cycle defects, non-ketotic hyperglycinemia and homocystinuria. The amino acid profile can be influenced by factors such as diet, nutritional status, medication, disease status, and inappropriate sample processing. Information regarding diet, nutrition, medication and medical history should be provided with the sample for optimal interpretation. In many cases, diagnostic work up should also include other metabolic profiles such as urine organic acids and/or plasma carnitine and acylcarnitine to compile a complete metabolic profile and reach an accurate diagnosis. Urine amino acids can evaluate renal function, some specific amino acid disorders and renal transport disorders. Quantitation of amino acids can also be performed on spinal fluid (CSF) when a defect of glycine or serine metabolism is clinically suspected. Diagnosis of glycine encephalopathy requires submission of concurrent plasma amino acids to determine the ratio of CSF/plasma glycine.

Specimen Requirements:

Plasma: One 5 ml tube of anticoagulated blood (fasting or a 2-4 hour postprandial) in sodium heparin (green top); centrifuge immediately and freeze plasma.
Urine: 5 ml (random or preferably morning first void) in a clean container without preservatives; freeze.
CSF: Collect 1 ml spinal fluid in a sterile container without additives; freeze. (Note: blood contamination can interfere with test results.)

Shipping: Ship overnight frozen on dry ice.

Turnaround Time:

5 days for routine samples.
Same day results available on an emergency basis. 
Please call the laboratory prior to sending a sample for STAT analysis.

CPT Codes:

Plasma: 80500, 82139, 82492
Urine: 80500, 82139, 82570, 82492
CSF: 80500, 82139, 82492

Consent Form: Postnatal Consent [PDF]

Requisition Form: General Test Requisition [PDF]