The patient’s genome harbours three heterozygous non-silent germline polymorphisms affecting the mitotic checkpoint proteins Aurora kinase A, BUB1 mitotic checkpoint kinase B, and succinate dehydrogenase subunit B, a germline polymorphism in the breast cancer 2 tumour suppressor and a polymorphism in the methylenetetrahydrofolate reductase protein. Here, BUB1 is linked to breast cancer.