The typical RBD clinical profile involves middle-aged and older men with violent and injurious dream-enacting behaviors, with over 80% of these patients eventually developing an α-synuclein neurodegenerative disorder, usually Parkinson’s disease or Lewy body dementia, with an interval of about a decade from RBD onset to overt neurodegeneration [112]. The gene discussed is SNCA; the disease is Parkinson disease.