However, the parental phase of these two variants is unknown, but the phenotype of this patient with two SYNJ1 mutations resembles that of the other PARK20 mutation carriers, who had atypical parkinsonism with early-onset disease (at 20–31 years), a rapid development of dyskinesias on levodopa, predominantly axial symptoms with rapidly progressing gait impairment and falls, oculomotor disturbances and orofacial dystonia at onset (Table 1). The gene discussed is SYNJ1; the disease is drug-induced dyskinesia.