BRCA1 and BRCA2 proteins: roles in health and disease.

Between 5% and 10% of all breast cancer is hereditary, with patients having a strong family history of the disease. The remaining 90-95% of cases are classed as sporadic. Within the inherited group, 80-90% of cases are the result of germline mutations affecting two recently identified genes: BRCA1 and BRCA2. Since the sequencing of these genes, considerable research on the genetics of the mutation carriers has been performed, with less attention having been focused on the BRCA1 and BRCA2 proteins themselves. The structure and function of the protein products thus continues to hold mystery and might be the key to the full understanding of this complex disease.