Table 3.

Rare organic acidurias [51]

Organic acidurias	Enzyme deficiency	Clinical features
Alkaptonuria	Homogentisic acid oxidase	Benign; ochronosis and arthritis late in life
Isolated 3 methyl crotonyl CoA carboxylase deficiency	3 methyl crotonyl CoA carboxylase	Acute metabolic acidosis, hypoglycemia, carnitine deficiency
3 methyl glutaconic acidurias	3 methyl glutaconyl CoA hydratase	Mild form—Mild acidosis, speech retardation; Second form—Dilated cardiomyopathy, neutropenia, growth retardation; Third form—Progressive neurologic deterioration, optic atrophy, hearing loss, movement disorders
HMG CoA lyase deficiency	HMG CoA lyase	Hypoglycemia, metabolic acidosis, no ketosis, hyperammonemia, vomiting, hypotonia, coma and death
Mevalonic aciduria	Mevalonate kinase	Dysmorphic features, anemia, hepatosplenomegaly, gastroenteropathy, failure to thrive, severe developmental delay
2 keto adipic aciduria	2 ketoadipic dehydrogenase	Benign; no clinical effects
Glutathione synthetase deficiency	Glutathione synthetase	Severe metabolic acidosis, CNS dysfunction, massive urinary excretion of 5-oxoproline