The dopa-responsive dystonia (DRD) caused by the autosomal dominant variant in the guanosine triphosphate cyclohydrolase-1 gene (currently identified as autosomal dominant DYT/PARK-GCH1) is mainly characterized by the appearance of posture and motor locomotion disturbances with marked diurnal variation in childhood or adolescence and a simultaneous or late occurrence of parkinsonism [[1], [2], [3]]. Here, GCH1 is linked to late-onset Parkinson disease.