Methylmalonic Acid and Homocysteine

Methylmalonic Acid and Homocysteine

Test Code

91003
83090, 83921
CPT Code is subject to a Medicare Limited Coverage Policy and may require a signed ABN when ordering.
91003
83090, 83921
CPT Code is subject to a Medicare Limited Coverage Policy and may require a signed ABN when ordering.
Not offered in Quest Nichols Institute - Chantilly, VA | Quest Diagnostics Nichols Institute (IFD) – San Juan Capistrano. Please provide SERVICE AREA INFORMATION to find available tests you can order.
In-home collection is not available in your area through Quest Mobile.

Clinical Significance

Methylmalonic Acid and Homocysteine - An elevated concentration of Homocysteine is an independent risk factor for cardiovascular disease. When used in conjunction with Methylmalonic Acid (MMA), these tests are useful to diagnose and monitor Vitamin B12 (cobalamin) and folic acid deficiency and are often useful in evaluating macrocytosis (an elevated MCV, an erythrocytic index).

Test Resources

None found for this test
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Test Details

Methodology

Methylmalonic Acid: Mass Spectrometry (MS) • Homocysteine: Enzymatic

Reference Range(s)

⁠⁠⁠⁠⁠⁠⁠Methylmalonic Acid

≤30 days87-580 nmol/L
31 days-11 months62-377 nmol/L
12-23 months55-347 nmol/L
2-59 years55-335 nmol/L
60-79 years69-390 nmol/L
≥80 years85-423 nmol/L

Homocysteine
AgeMale 
(umol/L)		Female 
(umol/L)
0-1 yearsNot EstablishedNot Established
2-9 years≤7.6≤7.6
10-14 years≤9.7≤8.4
15-17 years≤11.3≤10.2
18-29 years≤12.9≤10.9
30-49 years≤13.5≤11.0
>49 years≤15.2≤13.4

Alternative Name(s)

MMA and Homocysteine

LOINC® Codes, Performing Laboratory

Service Area must be determined

Methodology

Methylmalonic Acid: Mass Spectrometry (MS) • Homocysteine: Enzymatic

Reference Range(s)

⁠⁠⁠⁠⁠⁠⁠Methylmalonic Acid
≤30 days87-580 nmol/L
31 days-11 months62-377 nmol/L
12-23 months55-347 nmol/L
2-59 years55-335 nmol/L
60-79 years69-390 nmol/L
≥80 years85-423 nmol/L

Homocysteine
AgeMale 
(umol/L)		Female 
(umol/L)
0-1 yearsNot EstablishedNot Established
2-9 years≤7.6≤7.6
10-14 years≤9.7≤8.4
15-17 years≤11.3≤10.2
18-29 years≤12.9≤10.9
30-49 years≤13.5≤11.0
>49 years≤15.2≤13.4

Alternative Name(s)

MMA and Homocysteine
Service Area must be determined

Preferred Specimen(s)

2.7 mL serum

Alternative Specimen(s)

Serum collected in: Trace metal-free (royal blue-top) tube • Plasma collected in: Sodium heparin (green-top) or sodium heparin (royal blue-top) trace element-free with green band

Minimum Volume

1.1 mL

Collection Instructions

Red-top tubes: Place the specimen in a refrigerator or ice bath for 30 minutes after collection. Centrifuge the specimen as soon as possible after complete clot formation has taken place. Transfer the serum to a plastic screw-capped vial.

Barrier gel separator tubes: Place the specimen in a refrigerator for 30 minutes after collection. Centrifuge the specimen as soon as possible after complete clot formation has taken place. Do not place barrier tubes in an ice bath as freezing may prevent the barrier gel from adequately separating serum from cells.

Heparin tubes: Place the specimen in a refrigerator or ice bath until the specimen can be centrifuged. Centrifuge the specimen as soon as possible and transfer the plasma to a plastic screw-capped vial.

Transport Container

Transport tube

Transport Temperature

Refigerated (cold packs)

Specimen Stability

  • Room temperature: 4 days
  • Refrigerated: 7 days
  • Frozen: 6 months

Reject Criteria

Gross hemolysis • Grossly lipemic • Whole blood • Unseparated serum or plasma

Setup Schedule

Service Area must be determined
2.7 mL serum
Serum collected in: Trace metal-free (royal blue-top) tube • Plasma collected in: Sodium heparin (green-top) or sodium heparin (royal blue-top) trace element-free with green band
1.1 mL
Red-top tubes: Place the specimen in a refrigerator or ice bath for 30 minutes after collection. Centrifuge the specimen as soon as possible after complete clot formation has taken place. Transfer the serum to a plastic screw-capped vial.

Barrier gel separator tubes: Place the specimen in a refrigerator for 30 minutes after collection. Centrifuge the specimen as soon as possible after complete clot formation has taken place. Do not place barrier tubes in an ice bath as freezing may prevent the barrier gel from adequately separating serum from cells.

Heparin tubes: Place the specimen in a refrigerator or ice bath until the specimen can be centrifuged. Centrifuge the specimen as soon as possible and transfer the plasma to a plastic screw-capped vial.
Transport tube
Refigerated (cold packs)
Room temperature: 4 days
Refrigerated: 7 days
Frozen: 6 months
Gross hemolysis • Grossly lipemic • Whole blood • Unseparated serum or plasma
Service Area must be determined
Not offered in Quest Nichols Institute - Chantilly, VA | Quest Diagnostics Nichols Institute (IFD) – San Juan Capistrano. Please provide SERVICE AREA INFORMATION to find available tests you can order.
In-home collection is not available in your area through Quest Mobile.
Test Details

Clinical Significance

Test Resources

Reference ranges are provided as general guidance only. To interpret test results use the reference range in the laboratory report.

The CPT codes provided are based on AMA guidance and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.

This material contains content from LOINC® (http://loinc.org). The LOINC Table, LOINC Table Core are copyright © 1995-2019, Regenstrief Institute, Inc. and the Logical Observation Identifiers Names and Codes (LOINC) Committee and is available at no cost under the license at http://loinc.org/license.

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