For more than 20 years, AD remained a probabilistic clinical pathological syndrome [13], but with the gradual availability of biomarkers (initially non specific MRI measures of brain atrophy and PET measures of glucose hypometabolism; later CSF and PET measures of amyloid β and pathological tau [14]), new criteria were developed by the International Working Group (IWG), which incorporated biomarkers into the diagnostic assessment [7,15]. This evidence concerns the gene MAPT and Alzheimer disease.