GCH1 and cervical dystonia: We included nineteen articles describing dystonia patients with a variety of diagnoses: idiopathic or drug-induced blepharospasm, hereditary dystonia (DYT-GCH1, DYT-TOR1A, DYT-THAP1, and DYT-SGCE), idiopathic cervical dystonia, and a heterogenous group with focal, segmental, and/or generalized dystonia patients [35–53].