PRNP and early-onset autosomal dominant Alzheimer disease: Aggregation of amyloidogenic proteins is implicated in a variety of diseases, including transmissible spongiform encephalopathies (prion protein/PrP), light chain amyloidosis (immunoglobulin light chain), Parkinson’s Disease (α-synuclein/α-syn), type two diabetes (islet amyloid polypeptide/IAPP), transthyretin amyloidosis (transthyretin/TTR), and Alzheimer’s disease (amyloid-β/Aβ and microtubule-associated protein tau/tau)3,4.