Hyperammonemia due to methylmalonic acidemia

Hyperammonemia due to methylmalonic acidemia is a severe, life-threatening metabolic complication in patients with methylmalonic acidemia, an inherited organic acid disorder primarily affecting neonates, infants, and young children

Hyperammonemia due to methylmalonic acidemia is a severe, life-threatening metabolic complication in patients with methylmalonic acidemia, an inherited organic acid disorder primarily affecting neonates, infants, and young children It occurs when an enzymatic defect in methylmalonyl-CoA mutase or its cobalamin cofactors leads to the toxic accumulation of organic acid intermediates, such as methylmalonic acid and propionyl-CoA Clinically, affected patients present with acute encephalopathy, vomit...

Hyperammonemia due to methylmalonic acidemia is a severe, life-threatening metabolic complication in patients with methylmalonic acidemia, an inherited organic acid disorder primarily affecting neonates, infants, and young children

It occurs when an enzymatic defect in methylmalonyl-CoA mutase or its cobalamin cofactors leads to the toxic accumulation of organic acid intermediates, such as methylmalonic acid and propionyl-CoA

These metabolites secondary inhibit hepatic urea cycle function—specifically carbamoyl phosphate synthetase 1 and N-acetylglutamate synthase—preventing normal nitrogen clearance and triggering rapid ammonia accumulation

These metabolites secondary inhibit hepatic urea cycle function—specifically carbamoyl phosphate synthetase 1 and N-acetylglutamate synthase—preventing normal nitrogen clearance and triggering rapid ammonia accumulation

Clinically, affected patients present with acute encephalopathy, vomiting, lethargy, seizures, high anion gap metabolic ketoacidosis, and a high risk of cerebral edema

Clinically, affected patients present with acute encephalopathy, vomiting, lethargy, seizures, high anion gap metabolic ketoacidosis, and a high risk of cerebral edema