Some genes, such as apolipoprotein E (ApoE) and microtubule-associated protein tau (MAPT), are of particular interest because of their known association with dementia in other neurodegenerative diseases, such as Alzheimer's disease (AD) and atypical parkinsonian syndromes, including progressive supranuclear palsy and corticobasal degeneration (Morley et al., 2012) [5]. The gene discussed is APOE; the disease is early-onset autosomal dominant Alzheimer disease.