Assessing the HRs for CNV versus non-CNV pathogenic variants, separately for BRCA1 and BRCA2 suggested elevated breast cancer risk for BRCA1 deletions (HR = 1.21, 95%CI = 1.09–1.35) but not BRCA2 deletions (Table 1, Supplementary Data 9). This evidence concerns the gene BRCA1 and breast carcinoma.