Maternal and paternal lineage double heterozygosity alteration in familial breast cancer: a first case report

Hereditary breast cancer syndrome was firstly associated with BRCA1 and BRCA2 genes the mutations of which confer high risk to develop breast and/or ovarian cancer. Double heterozygosity is a rare condition in which both BRCA1 and BRCA2 mutations are present in a family at the same time. In the current study, a family with double heterozygosity has been reported. Furthermore, for the first time a molecular analysis in both proband lineages, maternal and paternal, has been reported to understand the provenience of both germinal mutations.The case regards a woman who developed breast and ovarian cancer with liver metastasis which presented two mutations, each in the two genes, transmitted from her mother and her father, respectively. In this family all available members have been investigated. The concomitant presence of these peculiar mutations was never reported before suggesting a link with Caucasian population from Southern Italy.