MAPT and Schnyder corneal dystrophy: In brief, 18% [13%–22%] of all participants have abnormal Aβ levels and a mean SCD‐severity score greater than 0 (Figure 1A1; SCD+Aβ+), and 6% [4%–8%] of participants across all samples also have abnormal tau levels (Figure 1B1; SCD+Aβ+T+), compared to 37% [29%–45%] and 27% [17%–37%] with mean SCD‐severity scores greater than 0 but normal Aβ levels (SCD+Aβ–) and tau levels (SCD+Aβ–T–), respectively.