The development of early-onset AD has been related to an altered genetic background, explained primarily by autosomal dominant mutations in APP (MIM #104760), Presenilin 1 (PSEN1) (MIM #104311), and Presenilin 2 (PSEN2) (MIM #600759) genes (Lanoiselée et al., 2017). This evidence concerns the gene PSEN2 and Alzheimer disease.