Many health systems currently have active programmes to identify carriers of rare, high-penetrance, mutations which increase risk for common diseases, such as familial hypercholesterolemia (FH) for CAD, mutations in BRCA1, BRCA2, ATM, CHEK2, and PALB2 for breast cancer, and Lynch syndrome for bowel cancer. This evidence concerns the gene CHEK2 and familial hyperaldosteronism.