Scientists in Oregon Create Embryos With Three Genetic Parents

Bioethics   |   Rebecca Taylor   |   Oct 25, 2012   |   10:14AM   |   Washington, DC

Over the last year there have been many headlines about the debate in the United Kingdom on whether to create embryos with three genetic parents. Now the debate has come to America where scientists in Oregon have created embryos that have genetic material from two women and one man.

Why would scientists want to engineer an embryo with the genetic material from three people? Because they say it will “prevent” the inheritance of mitochondrial disease. Not all of our DNA that we inherit is in the nuclei of the egg and sperm that join at fertilization. In the cytoplasm of our mother’s egg are mitochondria. Mitochondria have their own DNA called mtDNA. We inherit our mtDNA only from our mother because sperm’s mitochondria are dumped at conception. There are genetic mutations that cause very serious disease found in mtDNA and a woman with a such a mutation cannot help but pass this mutation on to her children.

Oregon scientists created a dozen human embryos using a technique called “maternal spindle transfer” which removes the nucleus of an egg from a woman with mitochondrial disease and places it into a donor egg with normal mtDNA. That genetically modified egg is then fertilized with the father’s sperm and a genetically modified embryo is the result. An embryo with the genetic material from two women and one man.

This modification has implications not only for the embryo but for future generations that cannot help but inherit the modification making this what is called germ-line genetic engineering.

From the AP story:

Scientists in Oregon have created embryos with genes from one man and two women, using a provocative technique that could someday be used to prevent babies from inheriting certain rare incurable diseases.

The researchers at Oregon Health & Sciences University said they are not using the embryos to produce children, and it is not clear when or even if this technique will be put to use. But it has already stirred a debate over its risks and ethics in Britain, where scientists did similar work a few years ago….

In June, an influential British bioethics group concluded that the technology would be ethical to use if proven safe and effective. An expert panel in Britain said in 2011 that there was no evidence the technology was unsafe but urged further study.

Laurie Zoloth, a bioethicist at Northwestern University in Evanston, Ill., said in an interview that safety problems might not show up for several generations. She said she hopes the United States will follow Britain’s lead in having a wide-ranging discussion of the technology.

While the kind of diseases it seeks to fight can be terrible, “this might not be the best way to address it,” Zoloth said.

I agree with Dr. Zoloth. Yes. Let us find a way to treat mitochondrial disease but not by using children and their descendants as unwitting experiments. We have no idea what the possible effects of having such a modification to an egg before fertilization may do the health and well-being of any children that result or to their children or children’s children.

In the wake of yet another study that found that IVF is linked to a greater risk of birth defects, is it really ethical to take the manipulation of human life in the lab even further? And will this technique open the door to more germ-line genetic engineering of our children?

Other countries like the UK have laws against such germ-line genetic modification in humans. Those laws would have to be amended to allow this technique to move forward. The United States does not have such laws. We only have the Food and Drug Administration (FDA) which has claimed authority over the manipulation of embryos in fertility treatments.



In fact, this is not the first time embryos with three genetic parents have been created in the United States. In the 1990s, embryologist Jacques Cohen used a similar technique called “cytoplasmic transfer” to make 17 children with the mtDNA of two different women making them the first genetically modified children to be born. Since then, one of the children has been diagnosed with “pervasive developmental disorder” and in a story from the Washington Monthly back in 2002, Jim Cummins, a molecular biologist at Murdoch University in Western Australia, said, “To deliberately create individuals with multiple mitochondrial genotypes without knowing the consequences is really a step into the dark.”

The FDA put a stop to Cohen and other fertility clinics performing cytoplasmic transfer. The Oregon group is looking to the FDA for approval to transfer genetically modified embryos like these into women. I hope the FDA again puts a stop to the whole process. What would be better are federal laws on the books prohibiting genetic modification of human embryos for any reason.