Amyotrophic onset in GCH1 doparesponsive dystonia

Dopa-responsive dystonia (DRD) belongs to combined dystonia syndrome (dystonia-plus syndrome)1 which encompasses non-degenerative and neurometabolic disorders characterized by combination of dystonia as the prominent sign, with another movement manifestation. Parkinsonism and myoclonus are the main disturbances accompany dystonia in the combined dystonia syndrome. Dystonia with parkinsonism includes DRD [DYT5, tyrosine hydroxylase (TH), and sepiapterin reductase (SPR)], dopamine agonist-responsive dystonia, rapid-onset dystonia parkinsonism (DYT12), and early-onset dystonia with parkinsonism (DYT16). However, dystonia combined with myoclonus is just classified as myoclonus dystonia (DYT11).