Selecting "healthy" embryos by preimplantation genetic diagnosis

I almost missed Good Morning America's piece about the couple who selected which embryos to implant so they could  "guarantee" that their child would not have breast cancer. So many, many misconceptions arise from this event, as well as challenges to individual personal values. Let me talk a bit about the misconceptions, since I'm not intending to challenge anyone's deeply held values. 

First, a great kudo for Robin, who carefully chose each word she spoke about the event and its implications.  Her introduction was clear and accurate, with just the right amount of interest and no hype. 

I was concerned about some of the comments and implications that we heard during the discussion with the physician who managed the in vitro fertilization and implantation.

The couple wished to avoid their child having breast cancer and knew that several women in the husband's family had died of breast cancer. He had genetic testing and was found to have BRCA gene(s). People who harbor one or both genes (in their "bad" form) are many times more likely to have breast cancer than those with the "good" form of one or both genes.

Read that last sentence again and note that I said people, not women.  No one in the interview mentioned whether the husband has taken any action to detect breast cancer in his own body. Men can have breast cancer, too. Nothing was said about whether the two embryos they selected for implantationwere male or female. Were they intentionally looking for a female without the BRCA problem?

I believe Robin mentioned that the BRCA genes account for only a small portion of genes known to be involved in breast cancer and that the great majority of breast cancers have not been found, so far, to be due to inherited genes. We don't know yet whether mutations after birth may also be responsible for breast cancer. These points should always be clearly made in discussing inherited breast cancer.

Robin kept emphasizing that the action of these parents meant that their child would not have "inherited" breast cancer. She was referring only to BRCA-connected cancers. There are many more breast cancer genes. 

The physician kept reminding the audience that he has been doing these type of genetic analyses since 1992 and none of his patients have ever abused the ability to diagnose genes before an embryo implants in the uterus. None of the parents undergoing the in vitro fertilization procedure made the decision "frivolously" or for reasons that were not "appropriate". This, to me, sounds much like the arguments many make for something they think can be used only for good. I will not judge whether many "good" decisions outweigh one "bad" decision. 

I read another couple of articles after I saw the piece on television and learned that the couple was fertile, but no one mentioned whether they had other children. I believe 12 embryos were tested and 5 were "good" and 7 "bad"; two of the 5 embryos without the BRCA gene problem were used for implantation. A fetus is developing. No one mentioned how many eggs were harvested from the mother, nor what trauma both parents had to endure to "ensure" that their child would be cancer-free. The piece on t.v. did say that the embryos not chosen for implantation were to be used to develop stem cells. 

Well, enough for the moment. Must return to house cleaning--yuck! Genetics is so much more fun!

Marie Godfrey, PhD







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