CPT Code:

82543

Availability:

Monday - Friday, 0800 - 1700.

Turnaround Time:

2 - 3 days.

Minimum Volume:

2.0 mL.

Specimen Handling:

Random urine, morning specimen preferred.  Refrigerate or freeze without preservative. No patient preparation necessary.

Interpretive Reference Range:

Normal < 20.2 mg/mg creatinine (per Mayo Medical Laboratory).

Use:

Diagnostic follow-up of increased C4 carnitine ester on newborn screen to confirm diagnosis of ethylmalonic encephalopathy.

Methodology:

Stable isotope dilution gas chromatography-mass spectrometry (GC/MS).