BRCA1, BRCA2 and breast cancer: a concise clinical review.

Less than 5% of breast cancers are hereditary, but over 90% of hereditary breast cancers are caused by a mutation of either BRCA1 or BRCA2. The mutation may be inherited from either the maternal or the paternal side of the family. Clinicians should consider specific criteria in the family history to determine when a patient may benefit from counselling and appropriate testing. Testing is generally offered only to patients who are at high risk …