Although not all samples were available for genotyping, family history shows two first cousins on the proband's maternal side, one diagnosed with HGSC at age 48 (PID: II‐20) and another diagnosed with HGSC (clinical stage IIIC) at age 67 (PID: II‐22) and is a heterozygote, transmitting RAD51C c.571 + 4A > G to her daughter (PID: III‐33) who was diagnosed with BC (invasive ductal carcinoma, clinical stage III, ER, PR, and HER2 negative) at age 37 and HGSC (clinical stage IIIB) at age 41. This evidence concerns the gene ERBB2 and breast cancer.