PSEN1-rs7523 (OR 0.39 [0.25–0.60]; P = 1.7 × 10−5) and PIWIL1-rs10848087 (β − 0.07 [− 0.11 to − 0.03]; P = 2.9 × 10−4) were associated with AD-Ct (Table 1; Fig. 2c; Supplementary Fig. S2c). The gene discussed is PIWIL1; the disease is Alzheimer disease.