2-Hydroxyvaleric acid is an organic acid present in human biofluids. Its presence in urine has been associated with lactic acidosis, which occurs in Succinic Acidemia (OMIM 600335 ), a syndrome of organic acidemia associated with congenital lactic acidosis and decreased NADH-cytochrome c reductase activity. 2-Hydroxyvaleric acid presence associated with lactic acidosis has also been found in Propionyl-CoA carboxylase deficiency (OMIM 253260 ), or Multiple carboxylase deficiency (MCD), an autosomal recessive metabolic disorder characterized primarily by cutaneous and neurologic abnormalities.