Catalyzes the oxidative decarboxylation of glutaryl-CoA to crotonyl-CoA and CO(2) in the degradative pathway of L-lysine, L-hydroxylysine, and L-tryptophan metabolism. It uses electron transfer flavoprotein as its electron acceptor. Isoform Short is inactive.
Isoform 1 and isoform 2 are expressed in fibroblasts and liver.
Defects in GCDH are the cause of glutaric aciduria type 1 (GA1) [MIM:231670]. GA1 is an autosomal recessive metabolic disorder characterized by progressive dystonia and athetosis due to gliosis and neuronal loss in the basal ganglia.