Breast and ovarian cancers are some of the most common tumors in females, and the genetic predisposition is emerging as one of the key risk factors in the development of these two malignancies. BRCA1 and BRCA2 are the best-known genes associated with hereditary breast and ovarian cancer. However, recent advances in molecular techniques, Next-Generation Sequencing in particular, have led to the identification of many new genes involved in the predisposition to breast and/or ovarian cancer, with different penetrance estimates. TP53, PTEN, STK11, and CDH1 have been identified as high penetrance genes for the risk of breast/ovarian cancers. Besides them, PALB2, BRIP1, ATM, CHEK2, BARD1, NBN, NF1, RAD51C, RAD51D and mismatch repair genes have been recognized as moderate and low penetrance genes, along with other genes encoding proteins involved in the same pathways, possibly associated with breast/ovarian cancer risk. In this review, we summarize the past and more recent findings in the field of cancer predisposition genes, with insights into the role of the encoded proteins and the associated genetic disorders. Furthermore, we discuss the possible clinical utility of genetic testing in terms of prevention protocols and therapeutic approaches. the recruitment of the recombinase RAD51 to the DNA double-strand breaks (DSBs) through the formation of a BRCA1-PALB2-BRCA2 complex. The BRCA2 protein contains a helical domain, three oligonucleotide binding domains, and a tower domain, which allow BRCA2 binding to both single-stranded DNA and double-stranded DNA [39,48,49].Germline PV/LPVs in the BRCA2 gene are associated with a 45-55% and 11-18% risk of developing BC and OC by the age of 70, respectively [20][21][22]. BRCA2 PV/LPVs have also been associated with an increased risk of BC in males, which is estimated at 6.8% by the age of 70 [43]. In addition, BRCA2 PV/LPVs have been associated with an increased risk of prostate cancer [50], pancreatic cancer [47,51], and uveal melanoma [52,53].According to the National Comprehensive Cancer Network (NCCN) guidelines, women with BRCA1/2 PV/LPVs should undergo a surveillance protocol, including clinical breast examination every 6-12 months and annual breast magnetic resonance imaging (MRI), starting at the age of 25, annual mammography with consideration of tomosynthesis, starting at the age of 30, and annual transvaginal ultrasound and serum CA-125 concentration, although of uncertain benefit, beginning at age 30-35 years [54]. Moreover, they should evaluate the opportunity of a bilateral risk-reducing mastectomy (RRM) and of a bilateral risk-reducing salpingo-oophorectomy (RRSO), typically at between 35 and 40 years and upon completion of childbearing [54]. Men with BRCA1/2 PV/LPVs should undergo clinical breast examination every 6-12 months, starting at the age of 35, and annual prostate cancer screening, starting at the age of 40 (in particular in BRCA2 PV/LPV carriers) [55]. In both sexes, screening for melanoma and pancreatic cancer should be evaluated on the basis of family...