Amino Acid Screen, Blood and Urine



To assist in diagnosing inherited metabolic disorders in infants, typically homocystinuria, maple syrup urine disease, phenylketonuria (PKU), and tyrosinuria.

Patient Preparation
Instruct the caregiver/patient that a 12-hr fast is required prior to the procedure, as protein intake may alter results. If the patient is a neonate, most state regulations require screening specimens to be collected between 24 and 48 hr after birth to allow sufficient time after protein intake for abnormal metabolites to be detected. As appropriate, provide the required urine collection container and specimen collection instructions.

Normal Findings
(Method: Liquid chromatography/mass spectrometry) There are numerous amino acids. Values vary, and the testing laboratory should be consulted for corresponding ranges.

Critical Findings and Potential Interventions

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