Methylmalonic aciduria is clinically similar to propionic acidaemia and is due to a deficiency of methylmalonyl-CoA mutase. It can also be due to defects in its cofactor, adenosylcobalamin. Adenosylcobalamin also known as coenzyme B12, cobamamide, and dibencozide, is, along with methylcobalamin (MeCbl), one of the biologically active forms of vitamin B12.
Methylmalonyl-CoA mutase (also known as methylmalonyl-CoA isomerase) is a protein that in humans is encoded by the MUT gene. This vitamin B12-dependent enzyme catalyzes the isomerization of methylmalonyl-CoA to succinyl-CoA in humans. Mutations in MUT gene may lead to various types of methylmalonic aciduria.
The mutase enzyme requires adenosylcobalamin (Ado-Cbl) as coenzyme so that the integrity of methylmalonic acid (MMA) metabolism is inextricably linked to vitamin B12 (cobalamin), its adequate intake and correct uptake, transport and intracellular metabolism. Deficiency of Methylmalonyl-CoA mutase leads to elevated levels of MMA in body fluids.
Methylmalonic aciduria
