Creatine Biosynthesis Testing : Creatine/Creatinine/GAA (Urine)

Test Information

Creatine biosynthesis disorders can be separated based on urine testing for guanidinoacetate (GAA) and creatine. Patients with AGAT deficiency show a low urinary GAA level while patients with GAMT have an elevated GAA level.

Turnaround Time

2 weeks

CPT Code(s)

82570, 82540, 82542

Cost

$190

Clinical Information

Both AGAT and GAMT are autosomal recessive disorders and are characterized by intellectual disability, speech delay and epilepsy. GAMT deficiency can also present with a dystonic hyperkinetic movement disorder.

Methodology

Analysis will be done by tandem mass spectrometry (MS-MS) with quantitation of creatine, GAA, and creatinine (for urine samples).

Specimen Requirements

Urine (at least 1 ml) is requested for the analysis. A fasting sample or first morning urine is preferred in males under 10 years of age.

Transport Instructions

Samples must be frozen and shipped on dry ice by overnight delivery services

Have Questions Need Support?

Call our laboratory at 1-800-473-9411 or contact one of our Laboratory Genetic Counselors for assistance.
Robin Fletcher, MS, CGC
Kellie Walden, MS, CGC

Analyte Analysis, Analytes and Biomarkers, Biochemical Testing
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