Alzheimer's disease (AD) is characterized clinically by impaired cognitive function (Förstl and Kurz, 1999) and neuropathologically by extracellular amyloid-beta (Aβ) plaques, intracellular neurofibrillary tangles of hyper-phosphorylated tau protein, and synaptic/neuronal loss resulting in regional hypometabolism and cortical atrophy (Mirra et al., 1991). The gene discussed is MAPT; the disease is Alzheimer disease.