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Methylmalonic Acid : 34879
Test CodeMMAQ or 34879
Alias/See Also
MMA
CPT Codes
83921
Preferred Specimen
2 mL serum
Minimum Volume
1 mL
Other Acceptable Specimens
Serum collected in: Royal blue-top tube • Plasma collected in: Sodium heparin (green-top) or sodium heparin (royal blue-top) tube
Instructions
Serum separator tube or a sodium heparin (green-top) tube.
Transport Container
Centrifuge serum separator tube and transport. If green top tube, centrifuge and aliquot 2 mL plasma (Min: 1 mL) into a standard transport tube.
Transport Temperature
Refrigerated
Specimen Stability
Room temperature: 4 days
Refrigerated: 7 days
Frozen: 10 months
Refrigerated: 7 days
Frozen: 10 months
Methodology
Mass Spectrometry (MS)
Setup Schedule
Sunday - Saturday
Report Available
4-5 days (From receipt at performing laboratory)
Reference Range
≤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
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
Clinical Significance
The Methylmalonic Acid (MMA) test is used in the diagnosis of acquired cobalamin (vitamin B12) deficiency in adults and to screen for inherited organic acidemia in neonates and infants. Elevated MMA in either blood or urine indicates vitamin B12 deficiency in adults, with MMA acting as a functional biomarker for vitamin B12 status. In neonates and infants, elevated MMA is associated with inborn errors of metabolism.
Adults with signs and symptoms of cobalamin deficiency, including peripheral neuropathy, ataxia, memory impairment, depression, behavioral changes, and anemia, should be tested for MMA, especially if they are elderly or have experienced intestinal malabsorption or digestive disorders. In the United States all newborns should be screened for MMA as part of the Department of Health and Human Services (HHS) Recommended Universal Newborn Screening Panel [1].
MMA can be acquired due to underlying medical conditions that lead to B-vitamin deficiencies or inherited as an autosomal recessive inborn error of metabolism. If a neonate or infant has elevated MMA suggestive of an organic acidemia, the parents may elect to undergo carrier testing, or have their other children undergo genetic testing. Siblings of a child with MMA-related mutation have a 25% chance of being affected and a 50% chance of being a carrier [2].
References
1. Department of Health and Human Services. Recommended Uniform Screening Panel. https://www.hrsa.gov/advisory-committees/heritable-disorders/rusp/index.html. Updated February 2019. Accessed July 2019.
2. Manoli, et al. Isolated methylmalonic academia. Updated: December 1, 2016. In: Adam MP, Ardinger HH, Pagon RA, et al. editors. GeneReviews [Internet]. Seattle (WA)L University of Washington
Adults with signs and symptoms of cobalamin deficiency, including peripheral neuropathy, ataxia, memory impairment, depression, behavioral changes, and anemia, should be tested for MMA, especially if they are elderly or have experienced intestinal malabsorption or digestive disorders. In the United States all newborns should be screened for MMA as part of the Department of Health and Human Services (HHS) Recommended Universal Newborn Screening Panel [1].
MMA can be acquired due to underlying medical conditions that lead to B-vitamin deficiencies or inherited as an autosomal recessive inborn error of metabolism. If a neonate or infant has elevated MMA suggestive of an organic acidemia, the parents may elect to undergo carrier testing, or have their other children undergo genetic testing. Siblings of a child with MMA-related mutation have a 25% chance of being affected and a 50% chance of being a carrier [2].
References
1. Department of Health and Human Services. Recommended Uniform Screening Panel. https://www.hrsa.gov/advisory-committees/heritable-disorders/rusp/index.html. Updated February 2019. Accessed July 2019.
2. Manoli, et al. Isolated methylmalonic academia. Updated: December 1, 2016. In: Adam MP, Ardinger HH, Pagon RA, et al. editors. GeneReviews [Internet]. Seattle (WA)L University of Washington
Performing Laboratory
Quest Diagnostics
