 Finally, the 2e−-reduced form of FAD is oxidized to two 1e− steps by an external electron acceptor to complete the turnover.Mutations in the GCDH gene can lead to defects in the enzyme encoded by it which leads to the formation and accumulation of the metabolites glutaric acid and 3-hydroxyglutaric acid as well as glutarylcarnitine in body fluids, which essentially leads to glutaric aciduria type I, an autosomal recessive metabolic disorder.Symptoms for this disease include