I was delighted to read about Katie Dowdy, a Colorado woman who used preimplantation genetic diagnosis (PGD) to make sure her two daughters wouldn’t carry an abnormal BRCA1 gene as Dowdy herself does. People with BRCA1 and BRCA2 mutations have a higher risk of certain cancers, including breast and ovarian cancers.
Dowdy’s story was featured in a recent article in The Wall Street Journal about couples choosing PGD, a procedure that helps identify genetic defects in embryos so a healthy embryo can be used for in vitro fertilization (IVF). I’m pleased that Dowdy has two healthy daughters who can grow up without concern over having a greatly increased risk for breast and ovarian cancer.
Through my work with FORCE (Facing Our Risk of Cancer Empowered) I have met many women and men whose lives have been touched by a hereditary risk for breast, ovarian and pancreatic cancers. Many members of FORCE have been diagnosed with cancer themselves or have lost family members to cancer. When you’ve had this experience, it is natural to want to protect yourself from cancer and to do everything within your means to protect your children and family members.
The Wall Street Journal article raises many of the issues that I bring up with patients when discussing the option of PGD. As a Licensed Certified Genetic Counselor, I always discuss PGD when I meet with young cancer patients who have not yet started planning a family or who are interested in having additional children.
It is important to understand that PGD is an invasive procedure and very expensive. Dowdy already was undergoing fertility treatment, so she and her husband only had to pay extra for PGD. Couples who do not have fertility issues must undergo IVF, which can cost at least $10,000, to produce and harvest the eggs, fertilize the embryos before they are tested by PGD, and then implanted. PGD adds another $6,000 to the cost. Every pregnancy conceived in this way must be screened by amniocentesis or CVS to ensure that the fetus does not carry a mutation. Amniocentesis and CVS are also invasive procedures that have a small risk for miscarriage.
When I think about reasons to have PGD, I think about genetic diseases that impact infants and children, such as cystic fibrosis. Parents who are carriers of a cystic fibrosis mutation have a 25 percent chance of having a child with cystic fibrosis. These parents may choose PGD to implant only those embryos that would not be affected with the disorder, which affects the lungs and digestive system. Other parents may choose to have a prenatal diagnosis to determine whether the fetus might be affected so that they can begin treatment at birth.
It is important to remember that BRCA mutations are associated with adult-onset diseases—cancers that affect adults. A female child conceived today, even if she does carry a BRCA mutation, will not be at risk for breast cancer until she is 25 years old and even then her risk will be minimal. I am hopeful that current methods of cancer detection, prevention and treatment will be so much more advanced 25 years from now that these children will not be at risk for cancer.