[Isovaleric acidemia]

The three first cases of isovaleric acidemia diagnosed in Scandinavia are described. The disorder is characterized by periodic vomiting, lethargy and coma accompanied by ketoacidosis and a "sweaty feet" odour. These attacks are often triggered of by upper respiratory tract infections or by ingestion of large amounts of protein. Often there are feeding difficulties because these children have aversion to protein-containing foods. Isovaleric acidemia can be subdivided into two types: an acute neonatal form and a chronic intermittent form. The basic defect is deficient activity of isovaleryl-CoA dehydrogenase, resulting in increased urinary excretion of mainly isovaleryl-glycine and 3-hydroxy-isovaleric acid. The defective gene is assigned to the long arm of chromosome 15, and at least five different mutations among 15 patients have been demonstrated. Therapy is symptomatic with correction of the metabolic acidosis and protein restriction and long term treatment with oral glycine and possibly carnitine.