SNCA and Alzheimer disease: Protein aggregation is considered a defining characteristic in multiple neurodegenerative disease which includes Amyloid Beta (Aβ) and Hyperphosphorylated tau (Tau) in Alzheimer’s Disease (AD), Alpha-synuclein (α-syn) in Parkinson’s Disease (PD) and poly-glutamine (poly-Q) in Huntington’s Disease (HD).