A polygenic risk score (PRS) for AD was created in LBC1936 using PRSice-2.104 Summary data from the largest clinically ascertained AD genome-wide association study, which included 21 982 people with AD and 41 944 controls, was used.105 As recommended by Leonenko et al.,106 a 2.2-Mb region of the genome containing the APOE region was removed prior to creating the PRS, and a P-value threshold of 0.1 was used for single nucleotide polymorphism (SNP) selection. The gene discussed is APOE; the disease is Alzheimer disease.