In this study, we examined the association between age of onset (AoO) and first clinical manifestation (FCM) with the APOE and DAOA genotypes, previously described as modifiers of clinical phenotypes in LOAD and EOAD in 88 individuals clinically diagnosed with AD-EOAD due to the PSEN1 A431E variant (39 females, 49 males). This evidence concerns the gene PSEN1 and Alzheimer disease.