Creatine Biosynthesis Disorders: Creatine/GAA Analysis (Plasma)

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

Turnaround Time

2 weeks

CPT Code(s)

82542

Cost

$200

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.

tandem mass spectrometry (MS-MS)

At least 500ul of plasma is requested for the analysis.

Whole blood should be shipped overnight at ambient temperature. Or, the specimen can be spun down, plasma removed and frozen. Frozen plasma should be shipped overnight on dry ice.