APOE and Alzheimer disease: For those SNPs contributing to score variability, we observe both single SNP variability events (top left plot quadrant—high weight variants with moderate levels of imputation variability like LPA and ANRIL for CAD and APOE for Alzheimer’s disease) as well as the accumulation of errors across multiple SNPs (bottom right plot quadrant—several low weight variants with a higher degree of imputation variability).