We detected nine pathogenic variants in 8 (10.66%) out of 75 selected breast cancer patients from families with hereditary breast and ovarian cancer syndrome, whose genetic tests for five BRCA1 mutations (c.5266dupC, c.181T>G, c.4035delA, c.68_69delAG, c.3700_3704delGTAAA) were negative. Here, BRCA1 is linked to breast cancer.