The near absence of APOEε4 alleles (only 3% in heterocygosis) and the higher proportion of ε2 alleles in this cohort (11% APOE ε2/ε3 instead of the population-based estimation of 6,8% [29]) may contribute to some extent to both an AD-protective factor and an exceptional longevity. This evidence concerns the gene APOE and Alzheimer disease.