Methylmalonic acid

Methylmalonic acid

Names
IUPAC name 2-Methylpropanedioic acid
Other names Methylmalonic acid
Identifiers
CAS Number	516-05-2 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:30860 N
ChemSpider	473 N
ECHA InfoCard	100.007.473
EC Number	208-219-5
KEGG	C02170 N
MeSH	Methylmalonic+acid
PubChem	487
InChI InChI=1S/C4H6O4/c1-2(3(5)6)4(7)8/h2H,1H3,(H,5,6)(H,7,8) N Key: ZIYVHBGGAOATLY-UHFFFAOYSA-N N InChI=1/C4H6O4/c1-2(3(5)6)4(7)8/h2H,1H3,(H,5,6)(H,7,8) Key: ZIYVHBGGAOATLY-UHFFFAOYAT
SMILES CC(C(=O)O)C(=O)O
Properties
Chemical formula	C4H6O4
Molar mass	118.088 g/mol
Acidity (pKa)	pKa1 = 3,07 pKa2 = 5,76
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Methylmalonic acid (MMA) (conjugate base methylmalonate) 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.

Increased methylmalonic acid levels may indicate a vitamin B12 deficiency. However, it is sensitive (those with the disease almost always test positive) but not specific (those that do not have the disease do not always test negative). MMA is elevated in 90-98% of patients with B₁₂ deficiency. It has lower specificity 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.

An excess is associated with methylmalonic acidemia.

MMA concentrations in blood are measured by Gas chromatographic Mass spectrometry or LC-MS and the expected values of MMA in healthy people are between 73-271 nmol/L.