Table 1.

Common organic acidurias

Organic aciduria	Enzyme deficiency	Salient clinical features	Incidence
Methyl malonic acidurias	Methyl malonyl CoA mutase	Neonatal or infantile metabolic ketoacidosis, failure to thrive, developmental retardation, megaloblastic anemia and macrocytosis	1:50, 000 (USA)
Propionic aciduria	Propionyl CoA carboxylase	Severe metabolic ketoacidosis in neonatal period, elevated 3 hydroxy propionate, methyl citrate, tiglyl Glycine, and unusual ketone bodies in urine	1:3000 (Saudi Arabia)–1:35,000 (USA)
Isovaleric aciduria	Isovaleryl CoA dehydrogenase	Acute episode of severe metabolic acidosis and moderate ketosis with vomiting, coma and death, odor of sweaty feet. Chronic, intermittent form with episodes of metabolic acidosis	1:250,000 (USA)
Maple syrup urine disease (MSUD)	Branched chain ketoacid dehydrogenase complex (BCKAD complex)	Burnt sugar odor to urine, convulsions, severe mental retardation, vomiting, acidosis, coma and death within the first year of life (Classic form)	1:100,000 (Higher prevalence in certain populations)
Glutaric aciduria Type I	Glutaryl CoA dehydrogenase	Dystonia, dyskinesia, excretion of glutaric and 3 hydroxy glutaric acids in urine, neuronal degeneration	1:75,000 (USA)
Multiple carboxylase deficiency	Acetyl CoA carboxylase, propionyl CoA carboxylase, 3 methyl crotonyl CoA carboxylase, pyruvate carboxylase (Biotin dependent enzymes)	Ketoacidosis, diffuse erythematous skin rash, alopecia, seizures, hypotonia, developmental retardation	1:100,000 (USA)