he 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
* This volume does not allow for repeat testing
Transport
< or = 30 days: 87 - 580 nmol/L
31 days to 11 months: 62 - 377 nmol/L
12 months to 23 months: 55 - 347 nmol/L
2 years to 59 years: 55 - 335 nmol/L
60 years to 79 years: 69 - 390 nmol/L
> or = 80 years: 85 - 423 nmol/L
he 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
Test is useful in the determination of certain genetic disorders and Vitamin B12 deficiency.
2 days
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