The prevalence is 1 in 155,000 (EU). It is due to a deficiency of isovaleryl-CoA dehydrogenase involved in the breakdown of the amino acid, leucine. It is an autosomal recessive disorder. The screening metabolite is isovaleryl carnitine, C5. The confirmatory tests are plasma acylcarnitines and urinary organic acids.
Previously published: 21/o7/14