In this study, we sought to clarify, early in the symptomatic phase, the relationship between the tau-selective PET tracer [18F]AV1451 and the more established measures of AD pathology: Aβ PET (using [18F]AV45 - florbetapir), CSF tau/p-tau, and Aβ, as well as cognitive performance. This evidence concerns the gene MAPT and Alzheimer disease.