Last Modified: 2/13/2019 3:06:03 PM

Medical Necessity Documentation:  
Client Notes:  
Patient Preparation:

Patient should be in a well-fed state

Specimen Requirements: 1.0 mL Serum from a Red Top Tube in a Plastic Vial 
Collection Instructions: Separate Serum by centrifugation
Freeze immediately after separation.

Minimum Volume: 0.4 mL Serum
Transport & Storage: Temperature/Stability: 5 hours Ambient
5 days Refrigerated
30 days Frozen (transport)

Avoid Thaw/Freeze Cycles
Rejection Criteria: Hemolyzed specimens
Reference Range:
Carnitine, Total
Adult Male 30-70 µmol/L
Adult Female 25-58 µmol/L
Male ≤17 Years 32-62 µmol/L
Female ≤17 Years 28-59 µmol/L
Carnitine, Free
Adult Male 23-59 µmol/L
Adult Female 19-48 µmol/L
Male ≤17 Years 25-54 µmol/L
Female ≤17 Years 19-51 µmol/L
Carnitine, Esters
Adult Male 4-15 µmol/L
Adult Female 4-13 µmol/L
Male ≤17 Years 4-12 µmol/L
Female ≤17 Years 3-16 µmol/L
Esterified/Free Ratio
Adult Male  0.12-0.39
Adult Female  0.13-0.42
Male ≤17 Years  0.09-0.35
Female ≤17 Years 0.09-0.49
Critical Ranges:  
Test Comments:  
Methodology: Chromatography/Mass Spectrometry
Clinical Significance: Serum carnitine analysis is useful in the diagnosis and monitoring of patients with carnitine deficiency (either primary or secondary). Primary carnitine deficiency is an autosomal recessively inherited genetic condition that affects carnitine uptake by cells and tissues through a defect in the plasma membrane carnitine transporter. Secondary carnitine deficiency can be seen in some disease states or in patients on carnitine-poor diets, but is also seen in a number of metabolic disorders. In these disorders, carnitine complexes with the accumulated substrate of the blocked metabolic step, and the resulting acylcarnitine ester is excreted in the urine, leading to a depletion of carnitine in the patient.
Custom Panel: No


Turn Around Time: 3 to 5 days
Days Performed: Monday, Wednesday, Friday, Saturday
Sites Performed: Quest - Chantilly to San Juan Capistrano
PHL Test Code: CARN
EPIC Test Code: LAB815
Send Out Test Code: 70107
Alternate Test Names: Carnitine Evaluation; Carnitine Free and Total
Included Tests: Carnitine, Total; Carnitine, Free; Carnitine, Esters; Esterified/Free Ratio
CPT Coding: 82379

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