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Medical Term:

methylmalonic aciduria

Pronunciation: meth′il-mă-lon′ik as′i-dyūrē-ă

Definition: Excretion of excessive amounts of methylmalonic acid in urine owing to deficient activity of methylmalonyl-CoA mutase or deficient cobalamin reductase. Two types occur: an inborn error of metabolism resulting in severe ketoacidosis shortly after birth, with long-chain urinary ketones; autosomal recessive inheritance, caused by mutations in the methylmalonyl-CoA mutase gene (MCM) on chromosome 6p [MIM*251000]; acquired, a type due to vitamin B12 deficiency [MIM*251110] due to defective synthesis of adenosylcobalamin.