C5-DC (Glutarylcarnitine) Analysis

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

• Glutaric Acidemia type 1 (GA1)

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.

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

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

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