TH is a well-established causative gene for DRD similar to GCH1, and mutations of TH and GCH1, resulting in deficiencies of the enzymes involved in the dopaminergic synthesis pathway, can present with dystonia and parkinsonism (Lee and Jeon, 2014; Wijemanne and Jankovic, 2015). The gene discussed is TH; the disease is dystonia 5.