Although several methods have been developed for diagnosis of AD, including quantification of amyloid-β (Aβ) and tau protein levels in cerebrospinal fluid, measurement of Aβ using positron-emission tomography imaging, and analysis of atrophy using magnetic resonance imaging, these procedures are either invasive (lumbar puncture) or expensive (imaging) [5-7]. The gene discussed is MAPT; the disease is Alzheimer disease.