CPT Code(s):
- Phenylalanine Only: 84030
- Tyrosine Only: 84510
- Phenylalanine and Tyrosine: 82136
Specimen Requirements:
Type: Dried blood spot
Special Instructions: Allow blood to dry completely before placing the specimen in a biohazard bag. Specimens sent through the mail do not require a biohazard bag.
Container/Tube:
- Newborn screening card or protein saver card
Sample Volume: 1 circle
Minimum Volume: 1/4 of 1 circle
Storage: Ambient
Stability (collection to time of analysis):
- Ambient: Stable
- Refrigerated: Stable
- Frozen: Stable
Rejection Criteria: Unidentified, diluted or contaminated, unsaturated
Use:
This test is used to monitor therapy in phenylketonuria and tyrosinema. It can also be used to evaluate previous phenylalanine and tyrosine elevations.
Methodology:
Liquid chromatography/Tandem mass spectrometry (LC-MS/MS)
Reported:
Within 3 days