| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
Methylmalonic Acid
Test Code34879
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
Transport Container
Serum separator tube (SST)
Transport Temperature
Room temperature
Specimen Stability
Room temperature: 4 days
Refrigerated: 7 days
Frozen: 10 months
Refrigerated: 7 days
Frozen: 10 months
Methodology
Mass Spectrometry (MS)
Setup Schedule
Daily
Report Available
6-7 days
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 |
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 [1].
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 [1]. 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 [2].
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 [3].
References
1. AACC. Methylmalonic acid. Updated May 10, 2019.
https://labtestsonline.org/tests/methylmalonic-acid. Accessed July 20, 2019.
2. 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.
3. 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 [1]. 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 [2].
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 [3].
References
1. AACC. Methylmalonic acid. Updated May 10, 2019.
https://labtestsonline.org/tests/methylmalonic-acid. Accessed July 20, 2019.
2. 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.
3. 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 Nichols Institute-San Juan Capistrano, CA |
| 33608 Ortega Highway |
| San Juan Capistrano, CA 92675-2042 |