Carnitine

Overview

  • EPIC Code:
  • LAB815
  • Soft Test Code:
  • CARN
  • Send Out Test Code:
  • 70107
Alternate Names
  • Carnitine Evaluation
  • Carnitine Free and Total
Included Tests

Carnitine, Total; Carnitine, Free; Carnitine, Esters; Esterified/Free Ratio


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.


Specimen Collection & Preparation

Patient Preparation

Patient should be in a well-fed state


Specimen Requirements

1.0 mL Frozen Serum from a Red Top Tube in a Plastic Vial 

Alternate Specimen

1.0 mL Frozen Plasma from a Green Top Tube - Na Heparin in a Plastic Vial 

TransportAndStorage

5 hours Ambient
5 days Refrigerated
30 days Frozen (prefered & transport)

Avoid Thaw/Freeze Cycles

Collection Instructions

Separate Serum by centrifugation
Freeze immediately after separation.




Clinical Interpretation

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


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.


Production Schedule

Sites Performed
  • Quest - Chantilly to San Juan Capistrano
Days Performed
Monday
Wednesday
Friday
Saturday
Departments
  • Sendouts - Clinical
Turn Around Time

3 to 5 days


Coding & Compliance

CDM

00910422


CPT Coding

82379