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Test Code MMAU Methylmalonic Acid, Quantitative, Urine

Reporting Name

Methylmalonic Acid, QN, U

Useful For

Evaluating children with signs and symptoms of methylmalonic acidemia using urine specimens

 

Evaluating individuals with signs and symptoms associated with a variety of causes of vitamin B12 (cobalamin) deficiency

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Urine


Specimen Required


Patient Preparation: Overnight fast required

Supplies: Urine Tubes, 10 mL (T068)

Container/Tube: Plastic, 10-mL urine tube

Specimen Volume: 4 mL

Collection Instructions: Collect second-voided specimen after an overnight fast.


Specimen Minimum Volume

1.2 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Frozen (preferred) 28 days
  Refrigerated  28 days
  Ambient  21 days

Reference Values

<3.60 mmol/mol creatinine

Day(s) Performed

Monday through Friday

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

83921

LOINC Code Information

Test ID Test Order Name Order LOINC Value
MMAU Methylmalonic Acid, QN, U 25116-5

 

Result ID Test Result Name Result LOINC Value
80290 Methylmalonic Acid, QN, U 25116-5

Interpretation

In pediatric patients, markedly elevated methylmalonic acid values indicate a probable diagnosis of methylmalonic acidemia. Additional confirmatory testing must be performed.

 

In adults, moderately elevated values indicate a likely vitamin B12 (cobalamin) deficiency.

Clinical Reference

1. Fenton WA, Gravel RA, Rosenblatt DS. Disorders of propionate and methylmalonate metabolism. In: Valle D, Antonarakis S, Ballabio A, Beaudet AL, Mitchell GA, eds. The Online Metabolic and Molecular Bases of Inherited Disease. McGraw-Hill; 2019. Accessed November 27, 2023. Available at https://ommbid.mhmedical.com/content.aspx?sectionid=225086103&bookid=2709

2. Klee GG. Cobalamin and folate evaluation: Measurement of methylmalonic acid and homocysteine vs vitamin B(12) and folate. Clin Chem. 2000;46(8 Pt 2):1277-1283

3. Watkins D, Rosenblatt DS. Inherited disorders of folate and cobalamin transport and metabolism. In: Valle D, Antonarakis S, Ballabio A, Beaudet AL, Mitchell GA, eds. The Online Metabolic and Molecular Basis of Inherited Disease. McGraw-Hill; 2014. Accessed November 27, 2023. Available at https://ommbid.mhmedical.com/content.aspx?sectionid=225548307&bookid=2709

4. Vashi P, Edwin P, Popiel B, Lammersfeld C, Gupta D. Methylmalonic acid and homocysteine as indicators of vitamin B-12 deficiency in cancer. PLoS One. 2016;11(1):e0147843

Report Available

3 to 5 days

Method Name

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

Forms

If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-Biochemical Genetics Test Request (T798)

-Benign Hematology Test Request (T755)