Overexpression of APP in Down’s syndrome is associated with AD pathology in humans.49 Recently, families have been identified in which a duplication of the APP gene leads to FAD, presumably because of overexpression of wild-type APP.50,51 Thus, there is a precedent for APP overexpression leading to AD in humans. Yet, there is no evidence for APP overexpression in either sporadic AD or in FAD associated with APP or presenilin mutations.
