C5-DC (glutarylcarnitine) Analysis

Test Information

Measurement of urine glutarylcarnitine (C5-DC) is available as an additional test for glutaric acidemia, particularly type I. While many patients with GA1 are identified via newborn screening, individuals who are considered low excretors may not be identified by this type of screening and by follow-up diagnostic testing. A low excretor will have normal or only mildly elevated biochemical analytes in the plasma, but will often have more distinctive elevations of C5-DC in the urine. Patients with glutaric acidemia type II will also typically show elevated glutarylcarnitine in urine.

Turnaround Time

10 days

CPT Code(s)

82017 & 82570

Cost

$242

Clinical Information

Glutaric acidemia type 1 (GA1) is an inborn error of lysine, hydroxylysine and tryptophan metabolism caused by the deficiency of glutaryl-CoA dehydrogenase (GCDH). GA1 is a neurodegenerative disorder with loss of neurons in the basal ganglia. Clinical features vary, but often include macrocephaly, gait abnormalities, hypotonia, spasms, rigidity and seizures. Retinal or subdural hemorrhages can also occur. Other than possible macrocephaly, patients appear normal at birth. Clinical features are typically preceded by an acute encephalopathic illness with fever before five years of age.

Methodology

Analysis will be done by tandem mass spectrometry (MS-MS) with quantitation of creatine and creatinine.

Specimen Requirements

At least 2ml of urine is requested for the analysis.

Transport Instructions

Samples must be frozen and shipped on dry ice via overnight delivery services.

Have Questions Need Support?

Call our laboratory at 1-800-473-9411 or contact one of our Laboratory Genetic Counselors for assistance.
Robin Fletcher, MS, CGC
Kellie Walden, MS, CGC

Analyte Analysis, Analytes and Biomarkers, Biochemical Testing, Newborn Screening Follow-Up
Lucy's Story

Lucy's Story

When our daughter Lucy had a metabolic crisis at 7 days old, we were shocked and devastated to find out that she was born with a rare genetic disorder (MSUD). Her newborn screening results did not make it back in time to prevent the crisis, and no one at our local hospital was familiar with the disease. They did not know how to treat her. Calls were made to Greenwood Genetic Center to confirm her diagnosis...

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