The diagnostic yield is increased to 93/112 (83.0%) if four additional high-penetrance breast cancer genes are included in the test panel (CDH1, PALB2, PTEN, TP53), and 100/112 (89.3%) if a broader panel of 15 moderate-penetrance breast-ovarian cancer genes listed in the National Comprehensive Cancer Network guidelines (including ATM, BARD1, BRIP1, CHEK2, NBN, NF1, RAD51C/51D, STK11) was used (p<0.01). This evidence concerns the gene RAD51C and Hereditary breast and ovarian cancer syndrome.