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Test ID C5OHU C5-OH Acylcarnitine, Quantitative, Urine

Useful For

Evaluation of patients with an abnormal newborn screen showing elevations of 3-hydroxyisovaleryl-/2-methyl-3-hydroxybutyryl-carnitine (C5-OH)

Genetics Test Information

Evaluation of patients with an abnormal newborn screen showing elevations of C5-OH. The results are not informative when patient is receiving L-carnitine supplements.

Highlights

Elevated 3-hydroxyisovaleryl-/2-methyl-3-hydroxy acylcarnitine (C5-OH) in plasma or newborn screening blood spots is due to one of several biochemical genetic diagnoses: 3-methylcrotonylglycinuria, 3-hydroxy 3-methylglutaryl-(HMG)-CoA lyase deficiency, beta-ketothiolase deficiency, 2-methyl 3-hydroxybutyryl-CoA dehydrogenase deficiency, 3-methylglutaconic aciduria, biotinidase deficiency or holocarboxylase deficiency.

 

Urine C5OH is useful in differentiating patients with 3-methylcrotonylglycinuria and with 3-methylglutaconic aciduria as they typically excrete larger amounts of C5-OH in urine compared to patients with the other diagnoses.

 

If patient is receiving L-carnitine supplementation, the result of this urine acylcarnitine test will not be informative.

Method Name

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

Reporting Name

C5-OH Acylcarnitine, QN, U

Specimen Type

Urine

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 (T068)

Specimen Volume: 5 mL

Collection Instructions:

1. Collect a random urine specimen.

2. Freeze specimen immediately.


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

Specimen Minimum Volume

1 mL

Specimen Stability Information

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

Reference Values

<2.93 millimoles/mole creatinine

Day(s) and Time(s) Performed

Monday, Wednesday, Friday

Performing Laboratory

Mayo Medical Laboratories in Rochester

CPT Code Information

82017

LOINC Code Information

Test ID Test Order Name Order LOINC Value
C5OHU C5-OH Acylcarnitine, QN, U In Process

 

Result ID Test Result Name Result LOINC Value
88830 C5-OH Acylcarnitine, QN, U 50091-8
28125 C5-OH Interpretation 59462-2
34469 Reviewed By No LOINC Needed

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.

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.