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Methylmalonic Acid (MMA), Serum Quantitative

MMA

Test Codes

MAYO: MMAS, EPIC: LAB6102, SOFT: XMMA

Department

Send Outs

Specimen Collection Criteria

Collect (preferred specimen): One plain Red-top tube.
Also acceptable: One Gold-top SST tube.

Physician Office/Draw Specimen Preparation

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells. Transfer serum to a plastic transport tube and refrigerate (2-8°C or 36-46°F).

Preparation for Courier Transport

Transport: 1.5 mL serum, refrigerated (2-8°C or 36-46°F). (Minimum: 0.5 mL)

Rejection Criteria

Specimens not collected and processed as indicated.

In-Lab Processing

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells. Transfer serum to a plastic transport tube and refrigerate (2-8°C or 36-46°F).

Transport: 1.5 mL serum, refrigerated (2-8°C or 36-46°F). (Minimum: 0.5 mL) 

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 48 days
Refrigerated (2-8°C or 36-46°F): 48 days
Frozen (-20°C/-4°F or below): 48 days

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to Mayo Medical Laboratories, Rochester, MN.

Performed

Monday – Friday.
Results available in 4-6 days.

Reference Range

By report.

Test Methodology

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

Interpretation

Elevated methylmalonic acid is an early and sensitive indicator of vitamin B12 (cobalamin) deficiency. Renal insufficiency and intravascular volume contraction can also elevate serum methylmalonic acid modestly (typically less than 1.0 mcmol/L).

Homocystine is an additional metabolite which is elevated in vitamin B12 deficiency, although homocystine is also elevated in folic acid and vitamin B6 deficiencies, as well.

Clinical Utility

This assay aids in the diagnosis of megaloblastic anemia. Elevated methylmalonic acid levels provide an early indication of cobalamin (B12) deficiency.

It is also useful for evaluating children with signs and symptoms of methylmalonic acidemia.

Cautions: Diet, nutritional status, and age should be considered in the evaluation of serum MMA level.

CPT Codes

83921
LOINC:  13964-2

Contacts

Last Updated

7/7/2021