The highest PPR was seen in APOE E4/E4 subjects compared to E4/E3 and E3/E3, consistent with prior work, as the effect of APOE and amyloid beta burden on accelerated cognitive and clinical decline in both Alzheimer’s disease and cognitively normal subjects is well-established.6 The gene discussed is APOE; the disease is early-onset autosomal dominant Alzheimer disease.