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
Not provided.
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 - Gluts + Eth + Meth Pnl SerPl
- 69845-6 - 2OH-gluterate SerPl-sCnc
- 69851-4 - 3OH-Glutarate SerPl-sCnc
- 27301-1 - Glutarate SerPl-sCnc
- 69829-0 - Me-succinate SerPl-sCnc
- 79476-8 - Ethylmalonate SerPl-sCnc
- 59462-2 - Clinical biochemist review
- 18771-6 - Provider signing name
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 |