SLC23A1 and Alzheimer disease: The leave-one-out permutation further showed that only the SLC23A1 rs33972313 variant largely changed the precision of the overall MR estimates in the IGAP AD GWAS dataset (Fig. 3), UK Biobank AD proxy phenotype GWAS dataset (Fig. 4), UK Biobank maternal AD and paternal AD GWAS datasets (Figs. 5 and 6), and cognitive performance GWAS dataset (Fig. 7).