--- Query Results ---

Program:Genetics and Genomics
Test Name:Phenylalanine & Tyrosine Monitoring (G&G South ACH)
Test Code:PHE, PHE-DBS
Performing Site: Alberta Children's Hospital
Performing Dept:Biochemical Genetics
Availability:Daily (plasma samples), Weekly (dried blood spot samples)
TAT:7 days
Preferred Tube/Container:Sodium heparin (dark green - NOT PST)
Alternate:Lithium heparin (dark green - NOT PST)
Pre-labelled Blood Spot Collection Card
Specimen Requirements: For Blood Samples
Collect 1 x 4 mL sodium heparin tube (or alternate tube type).

For Dried Blood Spot Samples
1. Self-collection of a sample by a patient using the pre-labelled phenylalanine blood spot card
    requires previous instruction by an ACH metabolic physician or an ACH metabolic dietician.
2. If the patient brings a pre-labelled phenylalanine blood spot card to collection lab, warm a
    finger or heel before collection and fill a minimum of two circles on the card using a single
    drop of whole blood (blood must soak through to the back of the card).
3. Do NOT smear blood onto the card or apply to both sides of card. If a single drop is
    insufficient, a second drop can be applied.
4. Do NOT use a capillary tube to transfer blood to the card.
Min. Sample Required:0.25 mL plasma, 2 full blood spots
Specimen Processing:For Blood Samples
At ACH only
The primary heparinized tube can be put on ice (ensure not to freeze sample) or refrigerated for routine pick-ups between 8:30 am – 2:30 pm, Monday through Friday.

For all other collections
1. Centrifuge.
2. Transfer plasma or serum to aliquot tube.
3. Write "NaHep", "LiHep" or "Red Top" on the aliquot tube label.
4. Freeze.

For Blood Spot Samples
1. Allow card to dry for a minimum of 4 hours after collection by clipping or lean card against an
    object on a clean, flat, non-absorbent surface.
2. Keep card away from sunlight and heat.
3. Place dry collection card inside a biohazard bag.
Specimen Handling:For Plasma Samples
Transport frozen samples on ice. Samples must not thaw during transport.

For Blood Spot Cards
Transport at ambient temperature.
Additional Information:Phenylalanine and Tyrosine Monitoring test may be collected any day, however if results are required by Friday, specimen MUST reach Biochemical Genetics Laboratory (located at ACH) by 1600hr on Wednesday.

ACH only: If the patient insists on a phenylalanine blood spot card and does not have a pre-labelled phenylalanine blood spot card with them, send the patient to the ACH Inherited Metabolic Disease Clinic.
Do not use newborn metabolic screen cards.

Samples will be rejected if:
  • Primary tube not refrigerated
  • Aliquot tube received thawed
  • Tube type not written on aliquot tube label
  • Dried blood spots are less than 2/3 full or have not been collected as described above
    Requisition/Form:Submit request using Biochemical Genetics Laboratory Requisition.
    Please ensure all required information, including patient's clinical history/indication, is provided on the requisition.
    Order Restrictions:This test is considered specialty testing; this test will be cancelled if sufficient clinical justification is not provided.
    Indications:This test is ONLY for monitoring known patients with a diagnosis of phenylketonuria/hyperphenylalaninemia. For the investigation of an undiagnosed patient with a suspicion of an amino acid disorder, the Amino Acids - Plasma (ACH) test should be ordered.
    Method:Plasma phenylalanine and tyrosine are detected using an Amino Acid Analyzer with internal standard. Dried blood spot phenylalanine and tyrosine are detected using liquid chromatography, electrospray-ionization tandem mass spectrometry (LS-MS/MS) with deuterium-labelled internal standards.
    Method Details:Phenylalanine and tyrosine monitoring allows for the assessment of a patient’s dietary phenylalanine tolerance following diagnosis, as well as ongoing adjustments based on their prescribed therapy to ensure the phenylalanine level remains within an acceptable range. It is recommended that all patients on dietary restriction therapy have a full plasma amino acid profile performed at least once a year, in addition to other micronutrient testing, for evaluation of potential nutritional deficiencies.
    Reference Interval:N/A
    Comments:Contact ACH Biochemical Genetics Laboratory (403-955-7379) for priority turn-around.
    Last Updated On:Monday, March 26, 2018
    Date of Last Review:Jan 2 2018 12:00AM