APP and early-onset autosomal dominant Alzheimer disease: One type of ADRD, early-onset Alzheimer’s disease (EOAD), afflicts about 5% of the population diagnosed with ADRD, while mostly heritable, the known genes associated with this prognosis are amyloid precursor protein (APP), presenilin 1 (PSEN1), and presenilin 2 (PSEN2) [66].