N-Isovaleroylglycine (Isovaleroylglycine) is an acyl glycine. Acyl glycines are normally minor metabolites of fatty acids. However, the excretion of certain acyl glycines is increased in several inborn errors of metabolism. In certain cases, the measurement of these metabolites in body fluids can be used to diagnose disorders associated with mitochondrial fatty acid beta-oxidation. Acyl glycines are produced through the action of glycine N-acyltransferase which is an enzyme that catalyzes the chemical reaction: acyl-CoA + glycine < -- > CoA + N-acylglycine. N-Isovaleroylglycine is a byproduct of the catabolism of the amino acid leucine. Accumulation of N-Isovaleroylglycine occurs in Isovaleric Acidemia (IVA).