Community Commentary: Knowing your genetic risk can save your life

An Ashkenazi Jewish woman in her 50s, Rachel, is diagnosed with breast cancer. Her mother, Sadie, age 80, has a history of melanoma, which was treated successfully. Sadie's younger sister, Zelda, died of breast cancer in her early 40s many years ago. Zelda had two daughters who live far away, with whom they have lost contact. Rachel's father and his family have no history of cancer.

An astute clinician recommends genetic counseling for Rachel and Sadie to estimate their risk of carrying the hereditary ovarian and breast cancer gene mutations for BRCA1 and BRCA2. While Sadie has no interest in being tested, Rachel is found to have the harmful BRCA2 gene change. She informs her immediate family, her parents and her two brothers, of this finding. Her brothers, who have daughters in their 20s, are entirely disinterested, having no knowledge of the ramifications of this information and no personal history of cancer.

Rachel finds her long-lost cousins, Zelda's daughters, who are in their 40s with no history of cancer. She urges them to get genetic counseling, as there is a high probability that their mother had a BRCA gene mutation.

After soul searching and multiple medical and psychological consultations, Rachel undergoes double mastectomies, a hysterectomy and removal of both tubes and ovaries.

While recovering from surgery and starting chemotherapy for her breast cancer, she summons the strength to explain to her brother's daughters, her nieces, their risk of carrying a BRCA gene mutation. Meanwhile her cousins, Zelda's daughters, have happily reentered her life, grateful for the family genetic information. One cousin is positive for the BRCA gene mutation as well, and opts for the same prophylactic surgery as Rachel.

Eventually, with pressure from a doctor friend and Rachel's nieces, her brothers undergo genetic counseling and gene testing. One is positive for the BRCA2 gene mutation and one is negative. This is consistent with the 50% chance that any child can inherit a BRCA gene mutation from a parent who carries it.