Abbreviations: Ab40: 40-amino-acid form of beta-amyloid, Ab42: 42-amino-acid form of beta-amyloid, CSF: cerebrospinal fluid, DM1: myotonic dystrophy type 1, ELISA: enzyme-linked immunosorbent assay, MA: mean age, MDD: mean disease duration, P-tau: phosphorylated tau, T-tau: total tau, y: years. Here, MAPT is linked to myotonic dystrophy type 1.