Some presenilin mutations and mutations in APP have been connected to CAA (Hendriks et al., 1992; Grabowski et al., 2001; Rossi et al., 2004; Bugiani et al., 2010; Sellal et al., 2017) and also a polymorphism in the neprilysin gene was associated with CAA (Kumar-Singh, 2008), although the exact connections between these mutations and AD/CAA symptoms and progression are not yet understood. Here, APP is linked to Alzheimer disease.