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U.S. Panel OKs Three-Parent Embryos with Sex Selection

scientistLast week a committee of scientists and ethicists have recommended to the Food and Drug Administration (FDA) that they approve three-parent embryo techniques for use in IVF in the United States. The committee calls it mitochondrial replacement

techniques (MRT) because the goal is too “replace” defective mitochondria in woman with mitochondrial disease so they do not pass their genetic mutation onto their children.

We all have genetic material outside our nucleus in our mitochondria called mtDNA. We inherit our mtDNA solely from our mother. The mitochondria we inherit are in our mother’s egg.

There are two MRT procedures that the committee endorsed. One takes a donor egg and removes its nucleus, replacing it with the nucleus of the egg of a woman with defective mtDNA. This creates a hybrid egg with the genetic material from two women. That genetically modified egg is then fertilized with sperm.

The second technique is a step further, manipulating not eggs but embryos after fertilization. It requires two embryos. One embryo with defective mitochondria and one “donor” embryo with healthy mitochondria. The nucleus of the healthy embryo is removed, and it is replaced with the nucleus of embryo with defective mtDNA. Two embryos are taken apart and destroyed to make a hybrid third embryo.

Both techniques are genetic engineering. Both techniques create embryos with genetic material from three people. Both are germ-line modifications, meaning they will be passed on to future generations by any female children made with these procedures.

In fact “mitochondrial replacement” is a misnomer. Actually all MRT procedures are “nuclear replacements.” In other words, the mitochondria are staying put. It is the nucleus that is being transferred. So in reality these techniques are practically similar to cloning or somatic cell nuclear transfer (SCNT) where the nucleus of an egg is replaced with a nucleus of a somatic cell and a cloned embryo is produced. It is well known that SCNT causes major birth defects and maternal mortality in animal models. Because of the invasive nature of nuclear transfer, MRT carries many of the same risks as cloning.

Last year the U.K. changed the definition of “genetically-modified” to circumvent the law and then approved MRT for use in fertility clinics. This committee agrees that the U.S. should also bring MRT to the IVF clinic but has some recommendations for restrictions that U.K. does not have. These restrictions are particularly telling.

The report is clear that MRT is to satisfy the “desires” – not “needs” – of a woman to have a genetically related child. This is an important point I will refer to later.

The committee recommends that MRT only be used for woman with serious, life-threatening mitochondrial disease. They are aware that there are other applications for MRT, including treatment of infertility in older women. The panel recognizes that there is a very slippery slope here that can quickly turn from procedures where the intent is to help the child, into procedures where it is the parents that benefit and the child carries all the risk.

They also recommend that the FDA require long-term follow up with these children to make sure they are healthy and do not suffer from long-term negative effects. This means that the committee is aware that there is serious potential for negative health affects, but they are willing to disregard those concerns for the “desires” of the mother to have a genetically related child. This also means that the child is the experiment. This is not mouse or primate models. This will be tried on real children, and they will be guinea pigs their entire lives.

The most telling and most insidious recommendation is that only male embryos be transferred to their mother’s uterus. The committee is concerned about negative effects not just for the children produced but for their children and grandchildren. They want the modification to stop with the child modified. Since mtDNA is passed from mother to child, transferring only male embryos ensures that the modification isn’t passed on. But the committee doesn’t mention what should happen to the female embryos. Make no mistake – female embryos will be made. They may be tossed out. More likely they will be frozen for future research. They certainly won’t get to finish out their lives.

Where are the feminists? Not only does MRT require donor eggs, which puts young women’s fertility and healthy at risk in the donation process, but the implied recommendation is to cull the girl embryos or sacrifice them to research.

The fact that the committee recommends only transferring male embryos sends a clear message that they are worried about unforeseen negative consequences, consequences that might be passed down to future generations. My question is, if you are so concerned about such risks why even allow it for male embryos? Are they not people as well? Do we not care about their well-being over the “desires” of a mother to have a genetically-related child?

This inherent sex-selection is simply a “feel-good” measure that is an attempt to mitigate serious concerns. Concerns that should put a stop to the whole thing.

The committee held a briefing and the video is on YouTube. At the end they took questions. The questions were excellent. One man pointed out that MRT is similar to cloning and another questioned the recommendation of sex selection. The committee dismissed both concerns; rather ineffectively in my opinion. And in the opinion of the interrogator, I think.

The bad news is that a powerful committee has recommended that the FDA approve germ-line genetic engineering of children in the United States.

The good news is that, as of now, the FDA cannot approve MRT. Just this year Congress passed language as part of the latest funding bill that prevents the FDA from approving “research in which a human embryo is intentionally created or modified to include a heritable genetic modification.” Dr. David Prentice at TownHall.com, calls this only a “pause” and not a permanent solution.

That restriction can be removed in the next funding bill, so it is imperative the U.S. enact some kind of legislation regulating germ-line genetic engineering in humans. The U.K. has moved forward with MRT and has now approved gene-editing of the nuclear DNA of embryos.

This genetic engineering slope is more slippery than a greased watermelon. It is time to get control of it before it is too late.


Rebecca Taylor is a clinical laboratory specialist in molecular biology, and a practicing pro-life Catholic who writes at the bioethics blog Mary Meets Dolly. She has been writing and speaking about Catholicism and biotechnology for six years and is a regular on Catholic radio.