The alpha-synucleinopathies (SNCApathies) are a group of several neurodegenerative diseases that are characterized by the pathological accumulation of alpha-synuclein aggregates in neurons and cells of the Central nervous system (CNS), including dementia with Lewy bodies (DLB), Parkinson’s disease (PD), or multiple system atrophy (MSA). The gene discussed is SNCA; the disease is Parkinson disease.