AD is the most common dementia with late-onset sporadic AD accounting for 95% while familial AD caused by autosomal dominant mutations accounts for less than 1% of all diagnosed cases.343 The accumulation of amyloid-β (Aβ) plaques and neurofibrillary tangles composed of hyperphosphorylated tau are pathological hallmarks of AD. The gene discussed is MAPT; the disease is Alzheimer disease.