APOE and Alzheimer disease: The polygenic risk score (PRS) approach aggregates the effects of multiple genetic markers identified through genome‐wide association studies (GWASs)2 and has shown great potential in identifying an individual's risk of developing AD.13, 14 A few studies have recently used AD PRS to predict mild cognitive functions and clinical MCI15; however, only one has suggested that PRS could identify MCI in middle aged adults16 more effectively than the APOE locus alone.