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9 Five to ten per cent of all breast carcinomas are of hereditary origin. Many of them have been associated to 10 mutations in the BRCA1 and BRCA2 susceptibility genes. No ‘‘BRCA3’’ gene has been found to account for 11 the non-BRCA1/BRCA2 breast cancer (BRCAx) families, and BRCAx tumors are increasingly believed to 12 originate from multiple distinct genetic events. Phenotype studies have questioned the existence of specific 13 ‘‘portraits’’ among hereditary breast carcinomas (HBC). They have shown that most BRCA1 tumors have a 14 ‘‘basal (epithelial)-like’’ aspect, while BRCA2 and BRCAx HBC are more heterogeneous. HBC have also 15 been submitted to genetic analyses, notably with the objective of resolving the heterogeneity of BRCAx 16 lesions. The present review aims to summarize recent data on BRCA1, BRCA2, and BRCAx HBC, 17 including hypotheses on the origin of BRCA1 tumors and their paradoxical relations to estrogen-sensitivity.