The equal distribution of the neurodegeneration marker N in the two MCI groups, the lack of longitudinal cortical thinning in our large A-T+ MCI cohort, and the presence of only hippocampal atrophy support that A-T+ MCI group with elevated p-tau levels may be reflective of PART pathology and can be confirmed only by histopathological studies (Jack et al., 2016a). The gene discussed is MAPT; the disease is hippocampal atrophy.