Using objective memory performance (word list delayed recall) as an additional covariate to control for subtle group deficits in cognition, we found that the SCD-plus score was still a significant predictor, explaining more variance than objective memory performance (as seen by the contribution to R2 in the prediction model) in CSF-Aß42 and CSF Aß-42/tau ratio (Table 4). This evidence concerns the gene MAPT and Schnyder corneal dystrophy.