Sign in →

Test ID C5DCU C5-DC Acylcarnitine, Quantitative, Urine

Useful For

Evaluation of patients with an abnormal newborn screen showing elevations of C5-DC

 

Diagnosis of glutaric aciduria type 1 deficiency

Method Name

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

Reporting Name

C5-DC Acylcarnitine, QN, U

Specimen Type

Urine

Collection Container/Tube: Clean, plastic urine collection container

Submission Container/Tube: Plastic, 10-mL urine tube (T068)

Specimen Volume: 5 mL

Collection Instructions:

1. Collect a random urine specimen.

2. Freeze specimen immediately.

Additional Information: Include patient's age, family history, clinical condition (asymptomatic or acute episode), diet, and drug therapy information.

Forms: New York Clients-Informed consent is required. Please document on the request form or electronic order that a copy is on file. An Informed Consent for Genetic Testing (T576) is available in Special Instructions.

Specimen Minimum Volume

1 mL

Specimen Stability Information

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

Clinical Information

An isolated elevation of glutarylcarnitine (C5-DC) in plasma or newborn screening blood spots is related to a diagnosis of glutaric aciduria type 1 (GA-1), also known as glutaric acidemia type 1. GA-1 is caused by a deficiency of glutaryl-CoA dehydrogenase. Follow-up testing is necessary for confirmation. Urinary excretion of C5-DC is a specific biochemical marker of GA-1 that appears to be elevated even in low excretors, affected patients with normal levels of glutaric acid in urine.

 

GA-1 is characterized by bilateral striatal brain injury leading to dystonia, often a result of acute neurologic crises triggered by illness. Many affected individuals also have macrocephaly. Dietary treatment and aggressive interventions during time of illness are recommended to try to prevent or minimize neurologic injury, which is most likely to occur in infancy and early childhood. Prevalence is approximately 1 in 100,000 individuals.

 

The American College of Medical Genetics (ACMG) newborn screening work group published diagnostic algorithms for the follow-up of infants who had a positive newborn screening result. For more information, see URL: http://www.acmg.net.

Cautions

The results of urine acylcarnitines are not informative when the patient is receiving L-carnitine supplements.

Day(s) Performed

Monday, Wednesday, Friday

Report Available

2 days (not reported on Sunday)

Performing Laboratory

Mayo Medical Laboratories in Rochester

Test Classification

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

CPT Code Information

82017

NY State Approved

Conditional