We leverage data harmonization approaches to minimize site-related differences and compare cortical thickness differences and longitudinal rates of atrophy in A-T+ participants, typical participants with MCI due to AD pathology with amyloid positivity (A+T+ MCI) and cognitively normal A-T- controls, i.e., those free of amyloid and p-tau pathology (Fortin et al., 2017). This evidence concerns the gene MAPT and Alzheimer disease.