It is widely suspected that pathogenesis of PD entails molecular deregulation that leads to α-synuclein misfolding and aggregation, Lewy body formation, an apparent spread from neuron to neuron, and consequent neurodegeneration of multiple neurons, but particularly the neuromelanin-containing neurons of the SNpc and locus coeruleus113,121–123. Here, SNCA is linked to Parkinson disease.