When presented as the first exam, the etiological diagnosis changed in 23% (10/43; χ2 = 0.9, p = 0.343) of dementia patients after amyloid-PET, and in 16% (7/43; χ2 = 5.14, p = 0.023) of dementia patients after tau-PET (Table 2), with no difference between the two exams (χ2=, p = 0.588). This evidence concerns the gene MAPT and dementia.