We did not identify personal histories of breast or colorectal cancer in individuals harbouring BRCA2, MSH2, or PMS2 mutations; cardiac arrest or strokes in individuals harbouring DSG2, DSP, KCNH2, KCNQ1, MYBPC3, MYL3, and SCN5A mutations; or elevated blood lipid levels in APOB carriers. This evidence concerns the gene KCNH2 and cardiac arrest.