Ordering Recommendation

Initial test to diagnose or rule out creatine deficiency syndromes following clinical presentation. Order Creatine Disorders Panel, Urine (2002333), simultaneously for proper result interpretation.

Mnemonic
CRTN DIS P
Methodology

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Performed

Mon

Reported

2-9 days

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

Green (Sodium or Lithium Heparin), Lavender (K2EDTA), Plain Red, or Serum Separator Tube (SST).

Specimen Preparation

Separate from cells within 6 hours of collection. Transfer 1 mL serum or plasma to an ARUP Standard Transport Tube and freeze immediately. (Min: 0.2 mL)

Storage/Transport Temperature

Frozen.

Unacceptable Conditions
Remarks

Clinical information is needed for appropriate interpretation. Additional required information includes age, gender, diet (e.g., TPN therapy), drug therapy, and family history. Biochemical Genetics Patient History Form is available on the ARUP Web site at https://www.aruplab.com/patienthistory or by contacting ARUP Client Services.

Stability

Ambient: 6 hours; Refrigerated: 1 week; Frozen: 6 months (Three freeze/thaw cycles are acceptable.)

Reference Interval
Available Separately
Components
Reference Interval
Creatine, Serum/Plasma By report
Guanidinoacetic Acid,  Serum/Plasma By report

Interpretive Data



Compliance Category

Laboratory Developed Test (LDT)

Note
Hotline History
N/A
CPT Codes

82540; 82542

Components
Component Test Code* Component Chart Name LOINC
2002330 Guanidinoacetic acid, Serum/Plasma 33244-5
2002331 Creatine, Serum/Plasma 15045-8
2002332 Creatine Disorder Serum/Plasma Interp
* 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
  • AGAT
  • Creatine, Plasma
  • Creatinine, plasma
  • GAA & Creatine
  • GAA + Creatine
  • GAMT
  • Guanidinoacetic Acid and Creatine
  • Guanidinoacetic Acid + Creatine
  • Guanidinoacetic acid, plasma
Creatine Disorders Panel, Serum or Plasma