The pathology of Alzheimer's disease can be divided in accumulation of aggregated proteins, particularly extracellular beta‐amyloid and intracellular phosphorylated tau, losses of synapses and neurons and reactive processes including activation of microglia, astrocytosis and regenerative processes of undetermined significance (Duyckaerts, Delatour, & Potier, 2009). The gene discussed is MAPT; the disease is early-onset autosomal dominant Alzheimer disease.