SNCA and Parkinson disease: PD is pathologically characterised by the dopaminergic neuronal loss in the substantia nigra pars compacta and other regions of the brain resulting in the degeneration of the nigro-striatal tract and loss of dopamine (DA)1 and by the presence of Lewy bodies and Lewy neurites consisting primarily of α-synuclein (α-syn) along with Parkin and ubiquitin2.