ABSTRACT
Episodic overwhelming illness with vomiting, ketosis, acidosis, and coma in ∼60% of patients, chronic intermittent disease with episodes of metabolic acidosis and psychomotor retardation in ∼40%; characteristic odor; urinary excretion of isovalerylglycine and 3-hydroxyisovaleric acid; C5 and C5/C3 acylcarnitine profile; deficiency of isovaleryl CoA dehydrogenase; and mutations in the IVD gene on chromosome 15q14-q15.
