ATP1A3 and Parkinsonism: Twelve other missense mutations in ATP1A3 have been identified in patients diagnosed with rapid-onset dystonia-parkinsonism (RDP; DYT12; OMIM: 128235), a movement disorder characterized by abrupt onset of the permanent symptoms of dystonia with parkinsonism, often after a stressful event, typically in late adolescence or early adulthood (Heinzen et al., 2014).