Dystonia, Childhood-Onset, with Optic Atrophy and Basal Ganglia Abnormalities, also known as mepan syndrome, is related to optic atrophy 1 and 3-methylglutaconic aciduria, type iii. An important gene associated with Dystonia, Childhood-Onset, with Optic Atrophy and Basal Ganglia Abnormalities is MECR (Mitochondrial Trans-2-Enoyl-CoA Reductase). Affiliated tissues include eye and brain, and related phenotypes are dysarthria and dystonia