MAPT and Schnyder corneal dystrophy: Analyses for dichotomized CSF total tau (cut-off > 375 pg/mL) (Fig. 2b) and CSF p-tau (cut-off > 52 pg/mL) (Fig. 2c) showed the same trend across the whole sample (total tau: Z = − 13.7, p-tau: Z = − 13.6) and within SCD (total tau: Z = − 5.5, p-tau: Z = − 3.9), MCI (total tau: Z = − 5.0, p-tau: Z = − 5.6), and AD dementia (total tau: Z = − 5.6, p-tau: Z = − 6.1) (all P < 0.001), as discordant patients had higher CSF total tau and p-tau levels than concordant-negative patients, while concordant-positive patients had higher CSF total tau and p-tau levels than discordant patients.