When should genetic testing be performed?

Only approximately 10-12% of all breast cancers are related to a genetic mutation.  This genetic mutation is suspected if there are multiple blood relatives with a breast and/or ovarian cancer history, there is early onset of breast cancer (<40 years of age), breast and ovarian cancer occur in the same individual, and if there is a family history of being of Ashkenazi Jewish decent with a family history of breast cancer of ovarian cancer.  If we suspect a genetic mutation may be present, we sent the individual for genetic counseling and testing.