In the models using an Alzheimer’s disease PGS with the APOE region included, having one copy of APOE-ε4 increased the odds of dementia relative to normal cognition by roughly twofold, while two copies of APOE-ε4 increased the odds of dementia by over fourfold (Table 2), holding all other variables constant. This evidence concerns the gene APOE and early-onset autosomal dominant Alzheimer disease.