Ordering Recommendation

Use for monitoring patients with an established diagnosis of phenylketonuria (PKU).

Mnemonic
PHE/TYR
Methodology

Quantitative Liquid Chromatography/Tandem Mass Spectrometry

Performed

Mon-Fri

Reported

2-5 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect

Green (sodium or lithium heparin).

Specimen Preparation

Transfer 0.5 mL plasma to an ARUP Standard Transport Tube. (Min: 0.25 mL)

Storage/Transport Temperature

Frozen.

Unacceptable Conditions

Hemolyzed specimens.

Remarks
Stability

After separation from cells: Ambient: Unacceptable; Refrigerated: 24 hours; Frozen: 1 month

Reference Interval
Test Number
Components
Reference Interval
0080315 Phenylalanine Monitoring, Plasma Effective November 18, 2019
Age Reference Interval
0-30 days 30-95 µmol/L
1 month - 11 months 30-90 µmol/L
1 year and older 30-82 µmol/L

0080355 Tyrosine, Plasma Effective November 18, 2019
Age Reference Interval
0-30 days 30-140 µmol/L
1-11 months 30-130 µmol/L
1 year and older 35-110 µmol/L

Interpretive Data



Compliance Category

Laboratory Developed Test (LDT)

Note

This test is designed to monitor treatment and compliance in PKU patients.

Hotline History
N/A
CPT Codes

82131; 84510

Components
Component Test Code* Component Chart Name LOINC
0080315 Phenylalanine, Plasma 14875-9
0080355 Tyrosine, Plasma 20660-7
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • PKU
  • Tyrosine
Phenylalanine and Tyrosine