It is known that there are genetic syndromes associated with an increased susceptibility to breast cancer (e.g., Li-Fraumeni syndrome, Cowden syndrome, Lynch syndrome, Familial breast cancer: BROVCA1-4, Ataxia-telangiectasia, CDH1-associated breast cancer, PALB2-associated breast cancer, Peutz-Jeghers syndrome, Neurofibromatosis type 1), but it is possible that there are even more genetic syndromes to be detected [21, 22]. The gene discussed is CDH1; the disease is breast carcinoma.