Hydroxyglutaric Acids, Glutaric Acid, Ethylmalonic Acid, and Methylsuccinic Acid, Serum
Use
This test is useful for the evaluation of patients with an abnormal newborn screen showing elevations of glutarylcarnitine (C5-DC) using serum specimens. It aids in the differential diagnosis of short chain acyl-CoA dehydrogenase and isobutyryl-CoA dehydrogenase deficiencies, and in diagnosing glutaric acidemia type 1 and type 2. It also provides second-tier newborn screening for follow-up of C4 acylcarnitine and glutarylcarnitine (C5DC) elevations which can differentiate diagnoses of short-chain Co-A dehydrogenase (SCAD) deficiency, isobutyryl-CoA dehydrogenase deficiency (IBDH), and ethylmalonic encephalopathy.
Special Instructions
Patient's age is required. If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen. Day(s) performed: Monday, Wednesday.
Limitations
Acylcarnitine analysis included in newborn screening detects several inborn errors of metabolism, but it cannot differentiate between several isomers. However, additional testing of 2-hydroxyglutaric acid, 3-hydroxyglutaric acid, glutaric acid, methylsuccinic acid, and ethylmalonic acid by LC-MS/MS allows better differentiation among these isomers. A limitation of SCAD deficiency diagnosis is that biochemical markers do not always correlate with clinical symptoms.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 92673-3
- 69845-6
- 69851-4
- 27301-1
- 69829-0
- 79476-8
- 59462-2
- 18771-6
Result Turnaround Time
3-7 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
0.1 mL
Minimum Volume
0.02 mL
Container
Plastic vial
Collection Instructions
Centrifuge and aliquot serum into a plastic vial.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 4 days |
| Refrigerated | 90 days |
| Frozen | 90 days |