Two forms of CAA are recognized: hereditary (rare) due to mutations in amyloid precursor protein, such as APP [e.g., KM670/671NL (Swedish), E693Q, APP D694N (Iowa)], and sporadic (idiopathic) commonly present in AD and elderly asymptomatic adults (Haglund et al., 2006; Viswanathan and Greenberg, 2011; Kanekiyo et al., 2012; Ghiso et al., 2014; Yamada, 2015; Bravo et al., 2021). This evidence concerns the gene APP and Alzheimer disease.