APP and neurodegenerative disease: APOE testing was not performed, but genetic testing did not identify any pathogenic mutations in 17 genes associated with neurodegenerative diseases [2], notably including the amyloid precursor protein gene (APP) (including duplication of APP), Presenilin 1 (PSEN1), Presenilin 2 (PSEN2) and microtubule-associated protein tau (MAPT).