methylmalonsyra

Methylmalonic acid is a dicarboxylic acid with the chemical formula C4H6O4. It is an organic compound that plays a role in human metabolism. Specifically, it is an intermediate in the breakdown of certain amino acids, namely valine, isoleucine, threonine, and methionine, as well as fatty acids with an odd number of carbon atoms. This breakdown pathway is essential for energy production and the synthesis of other molecules.

In the human body, methylmalonic acid is normally converted into succinyl-CoA, a compound that enters the citric acid cycle. This conversion is catalyzed by the enzyme methylmalonyl-CoA mutase, which requires vitamin B12 (cobalamin) as a cofactor. Therefore, vitamin B12 deficiency can lead to an accumulation of methylmalonic acid in the body.

Elevated levels of methylmalonic acid in the blood or urine are indicative of methylmalonic acidemia, a group of rare inherited metabolic disorders. These disorders are caused by genetic defects in the enzymes involved in the methylmalonyl-CoA pathway, most commonly affecting methylmalonyl-CoA mutase. Severe methylmalonic acidemia can lead to serious health problems, including neurological damage, developmental delays, and metabolic crises.

Measurement of methylmalonic acid levels is a common diagnostic test for vitamin B12 deficiency and for the diagnosis and monitoring of methylmalonic acidemia. Treatment for vitamin B12 deficiency involves vitamin B12 supplementation. For methylmalonic acidemia, treatment strategies often include dietary modifications to reduce the intake of precursor amino acids and, in some cases, carnitine supplementation.