As this study used a targeted sequencing approach of suspected breast cancer genes, it was informative for only BRCA2, PALB2 and CHEK2. Despite the small sample size, for each of these genes we found effect estimates consistent with our discovery analyses, which were maintained when adjusting for cancer status and within women not diagnosed with breast cancer (Supplementary Table 4). This evidence concerns the gene CHEK2 and breast carcinoma.