We now know more than ever before about the relationship between our genetic heritage and disease. In previous centuries humans barely even understood the process of how an embryo was formed, or who a fetus “belonged” to. One of the most popular theories, posited by Aristotle, was that all of the genetic information to create a person was contained within the father’s sperm. The child’s mother was merely a vessel for its gestation, providing the raw physical material but nothing more.

Today we know that we inherit genetic information from both of our parents. This genetic inheritance can be a blessing, such as inheriting a combination of immunities that leave us less vulnerable to a variety of pathogens than either of our parents. It can also be a curse, passing on debilitating diseases that can kill or disable, as is the case with Huntington’s disease.

Scientists have been able to identify over 200 diseases that are passed down from a mother through the mitochondrial DNA in her egg. They have also developed a technology to prevent this DNA, and therefore these diseases, from being inherited. But in order to do that, they need to create something that was not possible in Aristotle’s day. A child with three parents.

All About Eve

Every human being on the planet can trace their mitochondrial DNA back to one woman. Known as “Mitochondrial Eve” this woman, who lived somewhere in eastern Africa, passed on her mitochondrial DNA to her daughters (and sons) who then passed it on to their children. It isn’t really that she was the mother to every future human, as the name Eve might suggest. Rather she is our “most recent common ancestor.” This means that Eve’s children continued to have children–specifically, female children because only females pass on their mitochondrial DNA–while the other ladies had no children or only males–their mitochondrial DNA lines died out. Scientists have been able to use mitochondrial DNA to illuminate the ancient migrations of humans out of Africa and all over the world.

Its use for tracing human migration, and the diseases that damaged mitochondrial DNA can cause, are the main contributions of mitochondrial DNA. It isn’t a very significant percentage of your genetic inheritance, only containing 37 genes, compared to the more than 20,000 genes that humans possess. However, these genes can cause seizure disorders and the disintegration of brain tissue in some of the most serious illnesses that they trigger. Women who have faulty mitochondrial DNA were previously unable to have healthy, genetically related children. But with modern technology that is now possible.

How Do We Get Three-Parent Embryos?

The mother, or “primary mother,” has her egg harvested and the nucleus is removed. The “secondary mother” donates her egg as well, and the nucleus from this egg is removed and replaced by the nucleus from the primary mother. This egg is then fertilized by sperm. The resulting embryo has the genetic information from all three parents. Take a look at this CBS Sunday Morning video which gives a brief explanation of how the process works. It also alludes to the technology’s future implications.

There are several caveats to the use of this technology. The first caveat is that, unfortunately, that it does not guarantee a disease-free child. Up to 4 percent of the mutated DNA in the primary mother’s mitochondria can transfer into the embryo. Meaning that it is still possible for the child to inherit the diseases that the procedure was designed to eliminate. The risk is significantly lowered, but still exists.

What Critics Say

There are also some who suggest that investment into this research is misplaced. Mitochondrial disorders affect a very small percentage of people and keep only a few women, statistically speaking, from having children that are genetically related to them and also free from disease. If a woman knows that her child would inherit her damaged genes and likely develop a disorder she can still have a child, just not one that shares her genetic makeup. Research that helps treat these diseases would be better. Better still would be research that focuses on diseases that affect greater numbers of people where investments would get more value in the reduction of human suffering.

Additionally, our understanding of the relationship between genes and inherited traits is imperfect. We can trace certain diseases back to mitochondrial DNA and we know that the disorders they cause are directly related to the inheritance of those genes. But the interplay between the genes we inherit and the traits that develop is not always clearly understood, and manipulating them may prove to be more art than science. We may have the best of intentions to eliminate these diseases but the technology we use to do it could cause other problems that we cannot foresee.

Some scientists fear not only that we may inadvertently create other disorders with gene manipulation, but that we might be tempted to go beyond the elimination of disorders and start trying to select for “desirable” traits. On PBS News Hour, scientists discussed some of the implications of this technology as it evolves.

The ability to create a child with three parents (although since the genetic inheritance from the “secondary mother” is so small that may not be a fair characterization) would have seemed like science fiction 20 or even 10 years ago. Just as the technology to implant an embryo from one woman into the womb of another was unimaginable… right up until the moment it became reality. Scientists who are advocating restraint–those who fear that we may be tempted to use this technology to manipulate traits so that children can be custom designed by wealthy parents–are speaking about an outcome that is not possible. Yet. And while they may sound paranoid, the time to worry about the ethical implications of a new medical breakthrough is, ideally, before it becomes a reality. Not when the genie is already out of the bottle.

Molecular Scissors

The technology that scientists are worried about is “gene editing.” It sounds even more like science fiction than a three-parent embryo, but is quickly becoming scientific fact. In April, Chinese researchers were able to alter a gene in non-viable human embryos that dealt with human resistance to HIV.

Instead of replacing one of the cell’s pieces, as is done in mitochondrial DNA replacement therapy, gene editing actually manipulates the genes that are inherited. Mitochondrial DNA replacement therapy is kind of like getting a donated organ. Your liver is malfunctioning and so a donor gives you their liver. Or, in the case of a live donor, a lobe. The science is not changing the essential character of a human liver and it is a classic caveat emptor situation. You’re getting the liver you’re getting, with any of the attendant issues the new liver may possess, and no guarantees. But gene editing is more like a scientist looking at your malfunctioning liver, saying ‘we can do better,’ and using science to modify how the human liver functions. It is much more exciting, much less predictable, and much more like “playing God.”

The danger in the three-parent embryo technology is not so much the abuse of this technology. Other than the transfer of the nucleus into the donor egg the process is not “designing” a child any more than in-vitro fertilization does without a mitochondrial donor. Not that the process of in-vitro fertilization is without ethical quandaries, for there are many who think that this technology is immoral. But the debates on the ethics of in-vitro fertilization center on the creation of embryos that may never be implanted and the alleged selfishness of investing so much in being able to have a biological child when adoption remains an alternative. However, the ethical debate over mitochondrial DNA replacement is focused not on the danger in this technology but in the next technology that it will enable. This could be a situation where we are not merely trying to keep embryos from inheriting a disease but actively trying to modify how the human body responds to its environment.

Conclusion

Here in the United States, the use of mitochondrial replacement therapy was recently deemed ethical, at least for the creation of male embryos, but the therapy is unlikely to be experimented on soon. This is because male embryos will never be able to pass on mitochondrial DNA to their offspring. As a result, any inadvertently created errors won’t affect the next generation, which is a reasonable precaution which gives one pause about what “errors” we could create that affect the current embryo. The FDA has not approved it for clinical trials, but last year the technology was approved for clinical trials in the U.K. for embryos of either gender. Whether these trials–and the possibility for women with mitochondrial mutations to have healthy, genetically related children–are worth the Pandora’s box they open remains to be seen.

Resources

Goodreads: The Gene: An Intimate History

NBC News: Three-Parent Babies Are OK, Experts Say

PBS: NOVA: Neanderthals On Trial

NPR: Babies With Genes From 3 People Could Be Ethical, Panel Says

The Washington Post: To Prevent Disease Ethicists Approve Creation of Embryos With Three Genetic Parents 

The Telegraph: Three-Parent Baby Technique Could Still Pass On Mutated DNA

Genetics and Society: About Human Germline Gene Editing

Smithsonian Magazine: U.S. Panel Deems Three-Parent Babies Ethical

The United Mitochondrial Disease Foundation: Mitochondrial Replacement Therapy

Mary Kate Leahy

Mary Kate Leahy (@marykate_leahy) has a J.D. from William and Mary and a Bachelor’s in Political Science from Manhattanville College. She is also a proud graduate of Woodlands Academy of the Sacred Heart. She enjoys spending her time with her kuvasz, Finn, and tackling a never-ending list of projects. Contact Mary Kate at staff@LawStreetMedia.com

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It’s like the “X-Files,” but in real life! Researchers at the University of California, Davis want to create part-human, part-animal embryos, also known as chimeras, for the purpose of medical research.

The concept is that having access to an animal with certain human cells would allow for more accurate results when researching how different illnesses progress. The term “chimera” comes from Greek mythology–it’s a monster made up of several animals, for example a goat with a lion’s head and a snake’s tail. But actually creating chimeras in real life raises some important ethical questions. For example, the National Institutes of Health (NIH) has refused to fund the project, due to its controversial nature.

One of the possible end results would be to breed farm animals with human organs so that they could be donated to terminally ill people. But New York Medical School professor Stuart Newman thinks this is taking it a step too far: “You’re getting into unsettling ground that I think is damaging to our sense of humanity,” he told Boise State Public Radio.

Rob Stein, a Boise State Public Radio reporter, actually got a firsthand look at how the chimeras would be produced, by accompanying biologist Pablo Ross to his lab in California. They discussed a procedure that involved creating a human pancreas in a pig that could be eventually transplanted into a diabetes patient; it involves inserting human stem cells into pig embryos, and then implanting them in the pig.

These kinds of processes are where chimera critics worry things could go awry. Newman points out that if something were to go wrong, it could actually result in a pig with a human-like brain and some sort of human consciousness. Or an even weirder result–a pig giving birth to a part-human baby! As chimeras become a more likely reality, the question is if we really are willing to take that risk and cross those ethical lines.

Emma Von Zeipel

Emma Von Zeipel is a staff writer at Law Street Media. She is originally from one of the islands of Stockholm, Sweden. After working for Democratic Voice of Burma in Thailand, she ended up in New York City. She has a BA in journalism from Stockholm University and is passionate about human rights, good books, horses, and European chocolate. Contact Emma at EVonZeipel@LawStreetMedia.com.

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Sofia Vergara’s ex fiancé, Nick Loeb, is suing her for the rights to their frozen embryos.

Before the actress and Loeb separated they went through the process of medically creating and freezing embryos with the intention of using a surrogate to bring one or more of those embryos to term.

During this process, the couple decided to split up and a biological child was never brought into the world.

Vergara has since moved on and is now engaged to actor Joe Manganiello. Loeb, on the other hand, has publicly lobbied to regain ownership of the frozen embryos that were created while he was in a relationship with Vergara. He intends on using a surrogate to bring the embryo to term; however, Vergara does not want the embryo to result in a child. According to Loeb:

We signed a form stating that any embryos created through the process could be brought to term only with both parties’ consent. The form did not specify–as California law requires–what would happen if we separated. I am asking to have it voided.”

Loeb, creator of the Crunchy Condiment Company, has used his ex-fiance’s notoriety to catapult his own case into the pop-culture stratosphere. His main argument for why he should be allowed the rights to the embryos he made with his ex? Women have the power to bring a pregnancy to term even if the man objects, so he should be allowed to bring his unborn child into the world and raise it as he sees fit.*

(*Probably a flawed argument, considering most natural pregnancies are not preceded by legally binding contracts.)

But what happens if a couple warring over embryonic rights does not have any star power?

The topic of frozen embryo ownership isn’t just a celebrity issue. In the United States alone, 600,000 eggs are frozen every year. If freezing eggs is such a common practice, shouldn’t contracts regarding legal rights to frozen eggs be pretty standard? In America…not exactly.

Consider our British brothers and sisters who have fairly concrete laws regarding the process of freezing eggs:

In the U.K. for a couple to go through such treatment, they’d have to sign all the consent forms. If the couple split up, if one party withdraws the consent, the other party can’t use it at all.

In other words, if Vergara and Loeb were having this squabble in England, chances are that Loeb’s request to void the contracts would not be granted. Perhaps the realm of embryonic rights would become less of a gray area if the United States were to adopt the U.K.’s policy wherein consent must unequivocally come from both parties.

Corinne Fitamant

Corinne Fitamant is a graduate of Fordham College at Lincoln Center where she received a Bachelors degree in Communications and a minor in Theatre Arts. When she isn’t pondering issues of social justice and/or celebrity culture, she can be found playing the guitar and eating chocolate. Contact Corinne at staff@LawStreetMedia.com.

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