We analyzed only single-nucleotide variants and small indels, but structural variants are known to be associated with hereditary breast cancer.41 However, the proportion of pathogenic variants due to structural changes is reported to be very low for the BRCA1 and BRCA2 genes in Japanese populations.42 Lastly, we tested for a linear association in several statistical analyses; however, we had the potential to miss other patterns of association.43 In particular, biliary tract cancer in BRCA2 (eFigure 6 in the Supplement) showed an unusual pattern that should be investigated in further studies. This evidence concerns the gene BRCA1 and breast cancer.