Methylmalonic acid

Methylmalonic acid
IUPAC name methylmalonic acid
Other names 2-methylpropanedioic acid
Identifiers
CAS number	516-05-2
PubChem	487
MeSH	Methylmalonic+acid
Jmol-3D images	Image 1
SMILES CC(C(=O)O)C(=O)O
Properties
Molecular formula	C4H6O4
Molar mass	118.09 g mol−1
Y acid (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Methylmalonic acid (MMA) is a dicarboxylic acid that is a C-methylated derivative of malonate.

The coenzyme A linked form of methylmalonic acid, methylmalonyl-CoA, is converted into succinyl-CoA by methylmalonyl-CoA mutase, in a reaction that requires vitamin B₁₂ as a cofactor. In this way, it enters the Krebs cycle, and is thus part of one of the anaplerotic reactions.

Pathology

Increased methylmalonic acid levels may indicate a vitamin B₁₂ deficiency. However, it is sensitive without being specific. MMA is elevated in 90-98% of patients with B₁₂ deficiency. This test may be overly sensitive, as 20-25% of patients over the age of 70 have elevated levels of MMA, but 25-33% of them do not have B₁₂ deficiency. For this reason, MMA test is not routinely recommended in the elderly. ^[1]

An excess is associated with methylmalonic acidemia.

MMA concentrations in blood are measured by Gas chromatographic Mass spectrometry and the expected values of MMA in healthy people are between 73-271 nmol/L. ^[2]

See also

• Malonic acid

References

1. ^ B₁₂ Deficiiency and Dizziness
2. ^ http://scidok.sulb.uni-saarland.de/volltexte/2007/1076/pdf/Thesis.pdf