SNCA and Alzheimer disease: For instance, beta-amyloid (βA) aggregates are associated with AD, α-synuclein with PD and other synucleinopathies, hyperphosphorylated tau proteins with AD and other tauopathies, transactive response TAR DNA-binding protein (TDP)-43 inclusions with FTD, and polyglutamine protein aggregates are associated with HD, SCAs, and other movement disorders [7].