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Test Code C5DCU C5-DC Acylcarnitine, Quantitative, Random, Urine

Reporting Name

C5-DC Acylcarnitine, QN, U

Useful For

Evaluation of patients with an abnormal newborn screen showing elevations of glutarylcarnitine

 

Diagnosis of glutaric aciduria type 1 deficiency

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Urine


Ordering Guidance


This second-tier test is used specifically to evaluate a newborn screening elevation of glutarylcarnitine and must not be ordered with either C4U / C4 Acylcarnitine, Quantitative, Random, Urine or C5OHU / C5-OH Acylcarnitine, Quantitative, Random, Urine.

 

For general screening for metabolic disorders, see OAU / Organic Acids Screen, Random, Urine; ACRN / Acylcarnitines, Quantitative, Plasma; and AAQP / Amino Acids, Quantitative, Plasma.



Necessary Information


Patient's age, family history, clinical condition (asymptomatic or acute episode), diet, and drug therapy information is requested but not required.



Specimen Required


Patient Preparation: If clinically feasible, discontinue L-carnitine supplementation at least 72 hours before specimen collection.

Supplies: Urine Tubes, 10 mL (T068)

Collection Container/Tube: Clean, plastic urine collection container

Submission Container/Tube: Plastic, 10-mL urine tube

Specimen Volume: 5 mL

Collection Instructions:

1. Collect a random urine specimen.

2. Freeze specimen immediately.


Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time
Urine Frozen (preferred) 7 days
  Refrigerated  24 hours

Reference Values

<1.54 millimoles/mole creatinine

Day(s) Performed

Monday, Wednesday, Friday

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

82017

LOINC Code Information

Test ID Test Order Name Order LOINC Value
C5DCU C5-DC Acylcarnitine, QN, U 54279-5

 

Result ID Test Result Name Result LOINC Value
88831 C5-DC Acylcarnitine, QN, U 54279-5
28126 C5-DC Interpretation 59462-2
34470 Reviewed By 18771-6

Interpretation

Elevated excretion of glutarylcarnitine is a specific biochemical marker of glutaric aciduria type 1 that is elevated in affected patients, apparently even in low excretors, ie, those affected individuals with normal levels of glutaric acid in urine.

Clinical Reference

1. Miller MJ, Cusmano-Ozog K, Oglesbee D, Young S. ACMG Laboratory Quality Assurance Committee: Laboratory analysis of acylcarnitines, 2020 update: a technical standard of the American College of Medical Genetics and Genomics (ACMG). Genet Med. 2021;23(2):249-258

2. Larson A, Goodman S. Glutaric Acidemia Type 1. In: Adam MP, Feldman J, Mirzaa GM, et al, eds. GeneReviews [Internet]. University of Washington, Seattle; 2019. Accessed December 16, 2025. Available at: https://www.ncbi.nlm.nih.gov/books/NBK546575/

3. Guenzel AJ, Hall P, Scott AI, et al. The low excretor phenotype of glutaric acidemia type I is a source of false negative newborn screening results and challenging diagnoses. JIMD Rep. 2021;60(1)67-74

Report Available

2 to 5 days

Method Name

Flow Injection Analysis-Tandem Mass Spectrometry (FIA-MS/MS)