The main altered genes were: BRCA1, BRCA2, associated with high penetrance and increased risk of Hereditary Breast and Ovarian Cancer syndrome (HBOC); ATM, PALB2, CHECK2, RAD5C, BRIP1 with moderate or low penetrance and other less common ones such as MLH1, MSH6, MSH2, PMS2, TSC2, ERCC5, FANCL. This evidence concerns the gene MLH1 and Hereditary breast and ovarian cancer syndrome.