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Test ID: C5OHU    
C5-OH Acylcarnitine, Quantitative, Urine

NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.


Useful For Suggests clinical disorders or settings where the test may be helpful

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

Genetics Test Information Provides information that may help with selection of the correct test or proper submission of the test request

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.


  • 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.

Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test

Method Name A short description of the method used to perform the test

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

Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name

C5-OH Acylcarnitine, QN, U

Aliases Lists additional common names for a test, as an aid in searching

Hydroxymethylglutaryl-CoA (HMG-CoA) Lyase Deficiency
Multiple Carboxylase Deficiency
3-Hydroxy Isovalerylcarnitine
3-Methylcrotonyl-CoA Carboxylase Deficiency
3-Methylglutaconic Aciduria Type 1
3-Methylglutaconic Aciduria Type I
3-Methylglutaconyl-CoA Hydratase Deficiency
Acylcarnitines, Urine
Beta-Ketothiolase Deficiency
Biotinidase Deficiency
HCS Deficiency
HMG-CoA (Hydroxymethylglutaryl-CoA) Lyase Deficiency
Holocarboxylase Deficiency
Holocarboxylase Synthetase Deficiency