An amino acid analysis blood test is an evaluation of amino acid profile which serves as a good indicator of overall nutritional status. Free amino acids can be measured in plasma, urine, or cerebrospinal fluid (CSF), depending on the clinical concern. Plasma amino acids are indicated when following up infants with positive newborn screening result, evaluating patients with symptoms and signs of a possible metabolic condition (such as lethargy, vomiting, and failure to thrive), and monitoring individuals with a metabolic condition. This assay is sensitive in detecting specific amino acid disorders including phenylketonuria, maple syrup urine disease, tyrosinemias, urea cycle disorders, homocytinuria and various organic acidemias, etc.
Interpretation: For diagnostic purposes, it is best to combine amino acid findings with other metabolic profiles such as plasma acylcarnitine/carnitine and urine organic acids analysis to achieve an accurate diagnosis. Because plasma amino acid levels can be impacted by a patient’s nutritional and clinical status, a fasting or a pre-feed sample (infants) is required. Additionally, sample condition (hemolysis, etc) may also alter certain amino acid concentrations. Therefore, plasma should be immediately separated from the whole blood and kept frozen until submission. Urine amino acids are used to identify generalized or specific disorders of renal amino acid transport (eg, renal Fanconi syndrome, cystinuria). CSF amino acids are evaluated to identify disorders of amino acid metabolism that affect the central nervous system (eg, glycine encephalopathy and serine biosynthesis disorders). Concurrent plasma amino acids analysis is required when testing CSF amino acids for these conditions.
Sample: Arm vein blood. Nonfasting
Working day: Everyday
Result Time: 7 days 6:00 PM
