SNCA and Lewy body dementia: α-Synucleinopathies, which include Parkinson’s disease (PD), dementia with Lewy bodies (DLB) and multiple system atrophy (MSA), are characterized by accumulation of misfolded α-synuclein (α-syn) aggregates in neuronal and/or glial cells, and various pathological phenotypes and clinical symptoms are observed for each disease [22].