The histopathological hallmark of a number of neurodegenerative disorders, such as Alzheimer’s disease (AD), Pick’s disease, frontotemporal dementia with parkinsonism-17, and progressive supranuclear palsy, is the presence of fibrillar aggregates of tau protein in brain (1, 2, 3, 4, 5, 6, 7, 8). The gene discussed is MAPT; the disease is early-onset autosomal dominant Alzheimer disease.