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HelpTest Code HGEM Hydroxyglutaric Acids, Glutaric Acid, Ethylmalonic Acid, and Methylsuccinic Acid, Blood Spot
Useful For
Evaluation of patients with an abnormal newborn screen showing elevations of glutarylcarnitine (C5-DC) using dried blood spot 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 (IBDH) deficiency, and ethylmalonic encephalopathy.
Differentiating diagnoses of glutaric acidemia type I (GA-1) and glutaric acidemia type II (GA-2)
Special Instructions
Reporting Name
HGEM, BSSpecimen Type
Whole bloodNecessary Information
Specimen Required
Supplies: Card-Blood Spot Collection (Filter Paper) (T493)
Container/Tube:
Preferred: Card-Blood Spot Collection (Filter Paper) from heel or finger stick
Acceptable: PerkinElmer (formerly Ahlstrom 226) filter paper, Munktell filter paper, Whatman Protein Saver 903 paper, available newborn screening card, blood collected in tubes containing sodium heparin or EDTA and dried on filter paper
Specimen Volume: 2 Blood spots
Collection Instructions:
1. Do not use device or capillary tube containing ACD to collect specimen. Sodium heparin or EDTA are acceptable but must be spotted on card the same day as collected.
2. Completely fill at least 2 circles on the filter paper card (approximately 100 microliters blood per circle).
3. Let blood dry on filter paper at room temperature in a horizontal position for 3 or more hours.
4. Do not stack wet specimens.
5. Do not expose specimen to heat or direct sunlight.
6. Keep specimen dry.
Additional Information:
1. For collection instructions, see Blood Spot Collection Instructions.
2. For collection instructions in Spanish, see Blood Spot Collection Card-Spanish Instructions (T777).
3. For collection instructions in Chinese, see Blood Spot Collection Card-Chinese Instructions (T800).
Specimen Minimum Volume
1 Blood spot
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Whole blood | Ambient (preferred) | 123 days | FILTER PAPER |
| Frozen | 123 days | FILTER PAPER | |
| Refrigerated | 123 days | FILTER PAPER |
Reject Due To
| Shows serum rings Insufficient specimen Blood collected with ACD Nonapproved filter paper |
Reject |
Reference Values
2-OH Glutaric acid: ≤25 nmol/mL
3-OH Glutaric acid: ≤1.5 nmol/mL
Glutaric acid: ≤1.5 nmol/mL
Methylsuccinic acid: ≤0.45 nmol/mL
Ethylmalonic acid: ≤3.5 nmol/mL
Day(s) Performed
Monday, Wednesday
Report Available
3 to 7 daysSpecimen Retention Time
2 yearsPerforming Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
83918
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| HGEM | HGEM, BS | 92672-5 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 36048 | 2-OH Glutaric acid | 75037-2 |
| 36049 | 3-OH Glutaric acid | 82505-9 |
| 36050 | Glutaric acid | 82504-2 |
| 36051 | Methylsuccinic acid | 82503-4 |
| 36052 | Ethylmalonic acid | 82502-6 |
| 36053 | Interpretation (HGEM) | 59462-2 |
| 36054 | Reviewed By | 18771-6 |
Forms
1. Biochemical Genetics Patient Information (T602)
2. If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.