Methylmalonic Acid and Homocysteine

Test Code

30517

CPT Code(s)

83090, 83921

CPT Code is subject to a Medicare Limited Coverage Policy and may require a signed ABN when ordering.

Test Code

30517

CPT Code(s)

83090, 83921

CPT Code is subject to a Medicare Limited Coverage Policy and may require a signed ABN when ordering.

Not offered in Quest Diagnostics Nichols Institute (IFD) – San Juan Capistrano | Quest Nichols Institute -San Juan Capistrano, CA. 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 -

To diagnose and monitor vitamin B₁₂ (cobalamin) deficiency.

Test Resources

None found for this test
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Test Details

Methodology

Methylmalonic Acid: Tandem Mass Spectrometry • Homocysteine: Enzymatic

Reference Range(s)

⁠⁠⁠⁠⁠⁠⁠Methylmalonic Acid

≤30 days	87-580 nmol/L
31 days-11 months	62-377 nmol/L
12-23 months	55-347 nmol/L
2-59 years	55-335 nmol/L
60-79 years	69-390 nmol/L
≥80 years	85-423 nmol/L

Homocysteine

Age	Male (umol/L)	Female (umol/L)
0-1 years	Not Established	Not 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

LOINC® Codes, Performing Laboratory

Service Area must be determined

Methodology

Methylmalonic Acid: Tandem Mass Spectrometry • Homocysteine: Enzymatic

Reference Range(s)

⁠⁠⁠⁠⁠⁠⁠Methylmalonic Acid

≤30 days	87-580 nmol/L
31 days-11 months	62-377 nmol/L
12-23 months	55-347 nmol/L
2-59 years	55-335 nmol/L
60-79 years	69-390 nmol/L
≥80 years	85-423 nmol/L

Homocysteine

Age	Male (umol/L)	Female (umol/L)
0-1 years	Not Established	Not 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

LOINC® Codes, Performing Laboratory

Service Area must be determined

Preferred Specimen(s)

2.7 mL serum

Alternative Specimen(s)

Plasma collected in: Sodium heparin (green-top)

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 transport tube.

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 transport tube.

Transport Container

Transport tube

Transport Temperature

Room temperature

Specimen Stability

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

Reject Criteria

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

Setup Schedule

Service Area must be determined

Preferred Specimen(s)

2.7 mL serum

Alternative Specimen(s)

Plasma collected in: Sodium heparin (green-top)

Minimum Volume

1.1 mL

Collection Instructions

Transport Container

Transport tube

Transport Temperature

Room temperature

Specimen Stability

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

Reject Criteria

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

Setup Schedule

Service Area must be determined

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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