Subgroup analysis of HC individuals with normal Aβ42 levels (i.e. ≥600 pg/ml; n = 41) and SCD patients with abnormal Aβ42 levels (i.e. <600 pg/ml; n = 17) revealed no significant different tau plasma levels between both groups (HCs: 3.45 pg/ml vs. SCD: 3.29 pg/ml; p = 0.654). This evidence concerns the gene MAPT and Schnyder corneal dystrophy.