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Order Code HGEMS Hydroxyglutaric Acids, Glutaric Acid, Ethylmalonic Acid, and Methylsuccinic Acid, Serum

Useful For

Evaluation of patients with an abnormal newborn screen showing elevations of glutarylcarnitine (C5-DC) using serum specimens

 

Evaluation of patients with abnormal newborn screens showing elevations of C4- acylcarnitine to aid in the differential diagnosis of short chain acyl-CoA dehydrogenase and isobutyryl-CoA dehydrogenase deficiencies

 

Diagnosis of glutaric acidemia type 1

 

Aiding in diagnosis of glutaric acidemia type 2

Genetics Test Information

Second-tier newborn screening for follow-up of C4 acylcarnitine and glutarylcarnitine (C5DC) elevations.

 

Differentiating diagnoses of short-chain Co-A dehydrogenase (SCAD) deficiency, isobutyryl-CoA dehydrogenase deficiency (IBDH), and ethylmalonic encephalopathy.

 

Differentiating diagnoses of glutaric acidemia type I (GA1) and glutaric acidemia type II (GA2).

Method Name

Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

Reporting Name

HGEM, S

Specimen Type

Serum Red


Necessary Information


Patient's age is required.



Specimen Required


Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 0.1 mL

Collection Instructions: Centrifuge and aliquot serum into a plastic vial.


Specimen Minimum Volume

0.02 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Red Refrigerated (preferred) 90 days
  Frozen  90 days
  Ambient  4 days

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Reference Values

2-OH Glutaric acid: ≤4.5 nmol/mL

3-OH Glutaric acid: ≤0.7 nmol/mL

Glutaric acid: ≤0.8 nmol/mL

Methylsuccinic acid: ≤0.3 nmol/mL

Ethylmalonic acid: ≤1.5 nmol/mL

Method Description

An aqueous internal standard is added to the specimen. The supernatant is evaporated under heated nitrogen, and the residue is then reconstituted prior to injection onto a liquid chromatography tandem mass spectrometry (LC-MS/MS). The ratios of the extracted peak areas of glutaric acid, ethylmalonic acid, and methylsuccinic acid to their respective internal standards as determined by LC-MS/MS are used to calculate the concentration of each analyte in the sample.(Unpublished Mayo method)

Day(s) Performed

Monday, Wednesday

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

83918

LOINC Code Information

Test ID Test Order Name Order LOINC Value
HGEMS HGEM, S 92673-3

 

Result ID Test Result Name Result LOINC Value
36055 2-OH Glutaric acid 69845-6
36056 3-OH Glutaric acid 69851-4
36057 Glutaric acid 27301-1
36058 Methylsuccinic acid 69829-0
36059 Ethylmalonic acid 79476-8
36060 Interpretation (HGEMS) 59462-2
36061 Reviewed By 18771-6