For example, mutations in three deterministic autosomal dominant genes, i.e., presenilin 1 (PSEN1) on chromosome 14q, presenilin 2 (PSEN2) on 1q, and amyloid precursor protein (APP) on 21q, are associated with early-onset AD (EOAD) (Giri et al., 2016). The gene discussed is PSEN1; the disease is Alzheimer disease.