People with DS have an 90% chance of developing Alzheimer’s disease (AD)-like symptoms (AD-DS) that includes progressive dementia from about 40 years old preceded by Aβ plaques and neurofibrillary tangles (NFTs) of Tau accumulation resulting in neurodegeneration from about 10 to 20 years old (Zigman, 2013; Wiseman et al., 2015). The gene discussed is MAPT; the disease is Alzheimer disease.