Medical Genetics Test Details
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|Test Information:||This test provides quantitative analysis of Creatine and Guanidinoacetate in plasma and urine.
The test is useful for the evaluation of patients suspected of having disorders of Creatine Transport (OMIM 300352) and Synthesis, e.g. Guanidinoacetate Methyltransferase (GAMT) deficiency (OMIM 612736) and Argine:Glycine Amidinotransferase (AGAT) Deficiency (OMIM 612718).
Creatine deficiency syndromes are characterized by intellectual disability, severe disturbance of expressive and cognitive speech, seizures (often poorly controlled), and movement disturbances. A common hallmark is cerebral creatine depletion as detected by magnetic resonance spectroscopy.
In individuals with AGAT deficiency, both plasma and urine testing reveal extremely low guanidinoacetate (GAA) and creatine concentrations. In GAMT deficiency, high plasma GAA levels are characteristic. GAA is also mildly increased in urea cycle disorder patients with elevated arginine levels. In individuals with X-linked creatine transporter deficiency, urine is required for diagnosis, as plasma levels of GAA and creatine are typically normal in this disorder. The characteristic finding in the urine of individuals with creatine transporter deficiency is an elevated creatine/creatinine ratio.
To diagnose all three creatine deficiency syndromes, the Creatine Panel determines GAA and creatine in both plasma and urine by UPLC-tandem mass spectroscopy.
CEREBRAL CREATINE DEFICIENCY SYNDROME 1; CCDS1
CEREBRAL CREATINE DEFICIENCY SYNDROME 2; CCDS2
CEREBRAL CREATINE DEFICIENCY SYNDROME 3; CCDS3
CREATINE DEFICIENCY SYNDROME, X-LINKED
CREATINE TRANSPORTER DEFECT
MENTAL RETARDATION, X-LINKED, WITH SEIZURES, SHORT STATURE, AND MIDFACE HYPOPLASIA
MENTAL RETARDATION, X-LINKED, WITH CREATINE TRANSPORT DEFICIENCY
|Methodology:||UPLC-Tandem Mass Spectroscopy|
|Test Type:||Analyte Analysis|
|References Values or Ranges:||Ranges are provided in the report.|
|Sample & Shipping Information|
|Specimen Type:||Plasma and Urine|
|Requirements:||Draw blood in a Heparin (green-top) tube(s) and separate as soon as possible. Send 2 cc of plasma. Store the specimen frozen at -20°C. Specimen may be stored frozen for up to 14 days.
Send 2-4 cc of of a random urine. Do not add preservatives. Store the specimen frozen at -20C.
|Shipping Conditions:||Ship frozen on 3-5 lbs of dry ice in an insulated container by overnight courier.
|Turn Around Time:||10 days|
|List Price:||*For Insurance or Institutional Prices, please call.|
|CPT Codes:||82540 x 2, 82570 x 1|