Breast cancer is the most common malignancy in women around the world. About one in 12 women in the Westdevelop breast cancer at some point in life. It is estimated that 5%-10% of all breast cancer cases in women arelinked to hereditary susceptibility due to mutations in autosomal dominant genes. The two key players associatedwith high breast cancer risk are mutations in BRCA 1 and BRCA 2. Another highly important mutation canoccur in TP53 resulting in a triple negative breast cancer. However, the great majority of breast cancer casesare not related to a mutated gene of high penetrance, but to genes of low penetrance such as CHEK2, CDH1,NBS1, RAD50, BRIP1 and PALB2, which are frequently mutated in the general population. In this review, wediscuss the entire spectrum of mutations which are associated with breast cancer.