In this perspective we draw together the data from the genome wide association studies for Alzheimer’s disease, Parkinson’s disease and the tauopathies and reach the conclusion that in each case, most of the risk loci are involved in the clearance of the deposited proteins: in Alzheimer’s disease, the microglial removal of Aβ, in the synucleinopathies, the lysosomal clearance of synuclein and in the tauopathies, the removal of tau protein by the ubiquitin proteasome. The gene discussed is SNCA; the disease is Parkinson disease.