GCDH and glutaryl-CoA dehydrogenase deficiency: Glutaric aciduria type 1 (GA1, OMIM #231670) is a rare autosomal recessive disorder caused by the variants in glutaryl-CoA dehydrogenase (GCDH) gene, leading to a marked decrease in glutaryl- GCDH activity, which will resulting in the accumulation of glutaric acid (GA), 3-hydroxyglutaric acid (3-OH-GA), and glutarylcarnitine (C5DC) in various tissues, especially the brain (Kolker et al., 2006).