Consider the genetic phenotype “hereditary breast and ovarian cancer syndrome.” While this term is in common use, the lack of a standard terminology could result in one lab reporting the genetic phenotype as “BRCA1- and BRCA2-associated hereditary breast cancer,” while another may report it as “breast–ovarian cancer, familial 1.” In the former case, a clinician unfamiliar with the gene–disease association may only provide information about breast cancer, which is not consistent with evidence-based recommendations. This evidence concerns the gene BRCA1 and breast cancer.