In late-onset Alzheimer’s disease (AD), cognition can be influenced by several factors such as morphology of the gray matter cortex,1,2 white matter integrity3 and hippocampal volume.4 Certain genes such as apolipoprotein E (APOE) have been shown to influence memory and cognition.5-7 Education and lifestyle factors such as area deprivation index (ADI) are also associated with cognitive function.8,9 Recently, AD plasma biomarkers have emerged as potential predictors of cross-sectional cognitive outcomes and long-term cognitive decline. Here, APOE is linked to early-onset autosomal dominant Alzheimer disease.