NO MORE KIDDING AROUND
With advances in genetic manipulation leading to three-parent children, it’s not just kids asking, ‘Where do babies come from?’
In science fiction, designer babies never end well.
From Frankenstein to Brave New World, Gattaca and Blade Runner, attempts to genetically engineer humans result in disastrous social and political consequences, if not outright bloodshed. Perhaps the only thing worse than genetically engineering humans is genetically engineering velociraptors. The moral of the story is always the same: It’s best not to mess with the facts of life.
And so it’s understandable why so many people might be a little wary, if not downright terrified, of attempts to alter human DNA. Visions of perfectly symmetrical children with Kylie Jenner lips, Gisele Bundchen hair and Mark Zuckerberg brains ruling over an underclass of genetically unedited plebs dance in our heads.
Enter the latest development in reproductive technology: three-parent children. Three-person IVF, also referred to as mitochondrial replacement therapy (MRT), is a procedure that replaces a future baby’s mitochondrial DNA with that of a third party.
Humans have two types of DNA in their cells. The majority reside in a cell’s nucleus, but a small amount is found in the mitochondria. Mitochondrial DNA is only passed on by mothers because it’s transmitted through the egg. MRT takes the nuclear DNA from one woman’s egg and transplants into another woman’s un-nucleated egg. This can happen before or after fertilization.
Since the procedure replaces DNA outside of the nucleus, mitochondrial replacement isn’t considered gene editing, but rather genetic manipulation. The resulting child still contains over 99 per cent of the traditional mother’s and father’s DNA, with a teensy-tiny amount of a third woman’s DNA.
This is a potential game- changer for mothers at risk of passing on mitochondrial DNA mutations that can cause severe genetic diseases. We’re not talking about minor health problems; these conditions are devastating for both sufferers and their families and are estimated to affect one out of every 5,000 births.
One such disease is Leigh syndrome, a neurological disorder characterized by the loss of mental and movement abilities that typically results in death within two to three years. Another, myoclonic epilepsy with ragged- red fibres (MERRF), affects the muscles and nervous system and can cause recurrent seizures, difficulty coordinating movements, loss of sensation and dementia.
In a more recent development, MRT has also been heralded as a way for lesbian couples to have a child sharing both parents’ DNA. While their genetic contributions would not be equal, they would both be present.
However, MRT is a hotbed for biological, ethical and legal debate. Scientists and doctors are still unsure how safe it is or what the long- term side effects may be. There are issues surrounding consent, and of course there’s also the fear this will open the floodgates for more gene manipulation and editing, paving the path for true designer babies. When a three-parent child has children of his or her own, their DNA will be passed on affecting generations to come.
“What kind of impact will this have on the child? What types of questions is this child going to have? How are we going to provide the child with those answers? Is it safe?” asks Sherry Levitan, a Toronto-based fertility lawyer who sits on the board of directors of the Canadian Fertility and Andrology Society (CFAS).
MRT is not the only way parents with mitochondrial disease can have children without passing on the risk. “There are easier ways,” says Levitan. “You could use donor eggs. You could use another embryo. But this is the only way the child could be related to both of the intended parents.”
Going even further, the procedure prompts us to ask how important genetic kinship actually is: Does it outweigh medical, ethical and legal concerns? And if we decide it overrides health and ethical concerns, what does that say about families who don’t share DNA among all their members? Are they de facto “lesser-than” in the eyes of society?
Currently, MRT is illegal in Canada under the 2004 federal Assisted Human Reproduction Act, which bans altering the genome of a cell of a human being in a way that the alteration is capable of being transmitted to descendants.
In 2016, the first three- parent child was born in Mexico under the care of Dr. John Zhang and his team at the New Hope Fertility Center in New York City. The child’s mother carried mitochondria with mutations that can cause Leigh syndrome, which resulted in the deaths of her first two children. The procedure and birth took place in Mexico because MRT is also illegal in the U.S.
“Interestingly, it isn’t banned in the U. S. for medical, legal or ethical reasons. The FDA banned MRT because of funding limits put on it by congress,” says Levitan. In 2016, after a two-year study, the National Academy of Medicine (NAM) decided MRT was ethically permissible and granted approval for human research on MRT to move forward. However, in their decision, NAM referred to MRT as a “heritable genetic modification.” This put it in violation of congressional funding restrictions, and the FDA subsequently banned it. The research can’t be legally conducted in the U. S. because it can’t be legally funded.
In the U.K., the therapy was legalized in 2015, but medical facilities must be granted a licence to perform the treatment and can only be used by people with severe mitochondrial disease to avoid passing the condition onto their offspring. MRT is unregulated in Ukraine, where fertility researcher Valery Zukin continues to experiment with using three- parent IVF to solve infertility.
“There haven’t been any documented side effects so far, but because this is a new technology, we can’t be certain,” explains Stacey Hume, a molecular geneticist and associate professor in medical genetics at the University of Alberta. “We won’t really know until these children grow up and have undergone studies years later to find out if they’re still healthy.”
Many experts, including Hume, feel it’s time for Canada to re-examine the Assisted Human Reproduction Act. “Does it make sense in an area that’s developing and changing so quickly that we be reliant on a 15-year-old piece of legislation? No. There should be some mechanism for change and updating,” agrees Levitan. “We have some wonderful scientists in this country, and if they were to make some pleas to the powers that be, I think the government would be open to it.”
In terms of fears surrounding designer babies, Hume calls them unfounded. “The technique is very different than what would be considered a designer baby. As far as we know, the mitochondria doesn’t encode for any genes related to intelligence or outward appearance,” she tells me. “However, people worry that it’s just a slippery slope and if we allow mitochondrial replacement then will we allow replacement of other genes.”
If the Assisted Human Reproduction Act is updated to allow MRT, the next big question is who will have access to it? “We’re not at a point where it should be offered to any couple,” says Hume. “I think when there’s a documented disorder, that we’ll allow therapeutic intervention in limited instances and it’ll be carefully regulated.”
“Sex selection situations are going to be dealt with in a very different way,” says Levitan. With so many questions lingering about long-term medical effects and ethical concerns, she says it’s much harder to justify the risk for lesbian couples than for parents facing “catastrophic diseases.”
Ideally, the federal government would act sooner rather than later. Stalling on the issue could have unintended consequences. Desperate couples are likely to seek treatment in less-regulated environments, such as the couple who gave birth in Mexico. “We see this across the world with abortions. Where they’re restricted, people go off into other countries or to unlicensed clinics,” says Hume. “With a publicly funded healthcare system, these people still come back into that system, then we have to take care of those people.”
Biotechnology is advancing at a rapid pace and isn’t disappearing anytime soon. It seems infinitely more preferable to regulate its use early on rather than allow some sort of genetic engineering black market to fester. According to Hume, “if we don’t license it and there is a demand for it, couples will find a way to have it done.”
Now that sounds like the start of a dystopian sci-fi story.