Amyloid deposits are mainly composed of a specific disease-associated amyloidogenic protein, such as amyloid-β (Aβ) in Alzheimer’s disease [3], α-synuclein (αS) in Parkinson’s disease [4], and prion protein (PrP) in transmissible spongiform encephalopathy [5]. The gene discussed is PRNP; the disease is early-onset autosomal dominant Alzheimer disease.