Both SCD and MCI do notper seconstitute prodromal stages of AD, but they are associated with elevated risk to develop AD, particularly in individuals with the AD-typical findings in cerebrospinal fluid (CSF), that is, reduced levels of amyloid beta (Aβ1-42), and increased levels of total tau (tTau) and especially phosphorylated tau (pTau181) (Blennow & Zetterberg, 2010;Mattsson-Carlgren et al., 2023;Olsson et al., 2016). This evidence concerns the gene MAPT and Schnyder corneal dystrophy.