Test Overview
Test Methodology

Liquid Chromatography - Tandem Mass Spectrometry (LC-MS/MS) Stable Isotope Dilution Analysis

Test Usage

This test is useful for the evaluation of patients with a clinical suspicion of inborn errors of creatine metabolism, including arginine:glycine amidinotransferase (AGAT) deficiency, guanidinoacetate methyltransferase (GAMT) deficiency and cellular transport (CrT1) defects.

Reference Range *

Interpretive report provided.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Details
Days Set Up
Analytic Time

11 - 20 days

Soft Order Code
MiChart Code
Creatine Disorders Panel, Urine
Reference Laboratory
Mayo CRDPU (88697)
Special Testing
Specimen Requirements
Collection Instructions

Collect random urine specimen with no preservative. Aliquot 1 mL into a plastic urine container and freeze immediately.

Normal Volume
1 mL aliquot of random urine collection
Minimum Volume
0.5 mL aliquot of random urine collection
Additional Information

Panel includes creatine, creatinine, guanidinoacetic acid (GAA), and creatine/creatinine ratio. Test sent to Mayo Medical Laboratories.

CPT Code
82540, 82570, 83789
Fee Code
20320, AA180, AA181