Test ID: C5DCU
C5-DC Acylcarnitine, Quantitative, Urine
Useful For
Suggests clinical disorders or settings where the test may be helpful
Evaluation of patients with an abnormal newborn screen showing elevations of C5-DC
Diagnosis of GA-1 deficiency
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-DC. The results are not informative when patient
is receiving L-carnitine supplements.
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
An isolated elevation of glutarylcarnitine (C5-DC) in plasma or newborn screening blood spots is related to a diagnosis of glutaryl-CoA dehydrogenase (GA-1) deficiency. 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.
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 further information, see http://www.acmg.net.
Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
<1.54 millimoles/mole creatinine
Interpretation
Provides information to assist in interpretation of the test results
Elevated 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.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
The results of urine acylcarnitines are not informative when the patient is receiving L-carnitine supplements.
Clinical Reference
Provides recommendations for further in-depth reading of a clinical nature
Tortorelli S, Hahn SH, Cowan TM, et al: The urinary excretion of glutarylcarnitine is an informative tool in the biochemical diagnosis of glutaric acidemia type I. Mol Genet Metab 2005;84:137-143


