Phenylketonuria (Monitoring): Phenylalanine and Tyrosine, Quantitative
Test Code: BCG00002
Turnaround time: 1 week
CONDITION DESCRIPTION
Plasma amino acids analysis will detect specific amino acid disorders such as phenylketonuria (PKU), maple syrup urine disease (MSUD), urea cycle defects, non-ketotic hyperglycinemia and homocystinuria. Urine amino acids analysis can evaluate renal function, some specific amino acid disorders, and renal transport disorders. Plasma and urine amino acids values are compared to age-matched normal values. Quantitative analysis of amino acids can also be performed on spinal fluid. Filter paper analysis is used to monitor established patients diagnosed with PKU and MSUD.
INDICATIONS
This test is indicated in the case of:
- Infants with a positive newborn screening result indicative of a metabolic disorder.
- Evaluation of patients with signs of a possible metabolic condition, such as lethargy, vomiting, and failure to thrive.
- Monitoring for individuals diagnosed with a metabolic condition.
METHODOLOGY
Quantitative ion exchange chromatography.
DETECTION AND REFERENCE RANGE
Detection
This test is very sensitive for specific amino acid disorders, but detection can be sensitive to the age and eating status of the patient.
Reference range
Contact CEN4GEN for reference ranges if needed.
SPECIMEN REQUIREMENTS
Type: Dried Blood Spot
Specimen Requirements:
Peripheral blood from finger prick or heel stick spotted on filter paper, completely saturating the circle. Air dry sample.
Specimen Collection and Shipping: Do not expose specimen to heat or direct sunlight. Keep the specimen dry. Ship sample at room temperature with overnight delivery.
SPECIAL INSTRUCTIONS
- Please indicate any medications or dietary changes on the test requisition form.
