The APP gene consists of 17 exons in total and encodes several isoforms produced through the alternative splicing of exons 7 and 8 [40,41], three of which are relevant to Alzheimer’s disease as a neurodegenerative condition (isoforms 695, 751, and 770) and are expressed solely in the central nervous system [42,43]. The gene discussed is APP; the disease is early-onset autosomal dominant Alzheimer disease.