Description
Why It’s Done
This test is often ordered to:
• Screen for inborn errors of metabolism (genetic disorders), such as:
o Phenylketonuria (PKU)
o Maple syrup urine disease
o Homocystinuria
o Other amino acid metabolism disorders
• Investigate unexplained symptoms like:
o Developmental delay
o Neurological problems
o Failure to thrive in infants and children
• Help diagnose disorders affecting amino acid transport or metabolism
• Monitor patients with known metabolic diseases
Preparation for the Test
• Fasting: Usually, fasting for 8-12 hours before the test is recommended for accurate results; follow your healthcare provider’s instructions.
• Medications: Inform your healthcare provider about any medications, vitamins, or supplements you are taking, as some can affect amino acid levels.
• Avoid strenuous exercise before the test as it may alter amino acid concentrations.
• The test requires a blood sample, typically drawn from a vein in the arm


