Alzheimer disease (AD) is characterized by senile plaques comprised primarily of β-amyloid (Aβ) and hyperphosphorylated tau in the form of neurofibrillary tangles; however, the largest AD GWAS have not shown a genetic signal in the regions of APP or MAPT in late-onset AD (18). The gene discussed is APP; the disease is early-onset autosomal dominant Alzheimer disease.