We, along with other individual case reports, have observed MGA or IBC-MGA in BRCA1 germline mutation carriers, prompting us to investigate the potential association between IBC-MGA/MGA and BRCA1 germline mutations15,16 and homologous recombination-deficiency (HRD), a process underlying a subset of breast cancers. This evidence concerns the gene BRCA1 and breast carcinoma.