The real reason that we’ve never cloned a human, according to George Annas, a bioethicist at Boston University, is that there’s no point.
In most countries there are laws or agreements against artificially creating a genetic duplicate of another person, both because of ethical concerns and technical difficulties. Cloning is still far from a perfect science, and creating an imperfect clone would likely mean making a person with potentially devastating genetic abnormalities.
But even if we knew that we could successfully copy the exact genetic code of another person, Annas asks: “Why would you want to duplicate a human?”
“Nobody’s got a perfect genome,” he explains, and there’s no reason to make a copy of all of someone’s imperfections and disorders.
Making a genetically modified human — not a clone of an existing one — could be a different story. But the questions of how and why raise tricky ethical issues we’ve only begun to grapple with. It’s long past time to face those questions head on — and figure out where we really stand.
New genetic editing technologies that are becoming more refined every day could allow us to make edits to the genome of a human embryo, potentially fixing problems. Some argue that we should allow this, that it’s in fact inevitable — but Annas thinks we should be cautious.
When talking about editing embryos, people often make the argument that we can and should use genetic editing technology to remove genetic defects from human embryos. If you have an embryo that’s going to be born with a genetic disorder, especially one caused by a single mutation, you could remove that mutation from the embryo. When a research team from Sun Yat-sen University in China (imperfectly) edited non-viable human embryos, they were doing exactly that sort of thing — trying to make an edit that would remove a rare blood disorder.
But while it’s hard to argue against modifying an embryo to remove a devastating illness, Annas says that this — just like a cloning a human — is unnecessary.
In the scenario where you have an embryo that you can edit, you’re already planning on doing in vitro fertilization. And when doctors do IVF, they generally create a number of embryos and then choose one to implant. Since we can already test those embryos for genetic disorders, in most cases we can choose one without a particular genetic illness — eliminating any need to edit DNA.
Even in the case of rare dominant genetic disorders like Huntington’s disease, where a single chromosome carrying the genetic defect is enough to cause the disorder, a parent will only pass on the genetic code for that disease in 50% of cases. The only exception would be if a person carried that disorder in both chromosomes, which is exceedingly unlikely, since it would mean that two people with that rare disorder would have to have had a child together.
Those exceedingly rare cases aside, “no one’s come up with a good reason” to edit embryos, Annas says, “unless you want to make a better baby.”
If we’re really going to talk about editing human embryos, he argues that we should be honest about what we’re talking about: trying to improve the human genetic code. While many use the term “designer baby” for this, Annas prefers “better,” as the simplicity gets across the real — and potentially disturbing — implications of this discussion.
When we talk about about “better,” we’re making very real value judgments about our genetic code and its worth.
“I hate to say we’ll never know what [an ideal genome] is, but we’re nowhere near that,” Annas says. “I think we need an international discussion” to determine how we approach editing DNA in human embryos.
After all, he says, we’ve tried to define “better” human characteristics before. That turned out to be the eugenics movement, which, as an article in the journal Nature Education notes, “ultimately went horribly wrong.” It’s dangerous territory we’re wading into.
If we’re not ready to decide what the genetic code for a “better” human looks like, he says, then parents are not ready to make that decision for their children.
“Humans have more flaws than we know what to do with,” says Annas. “One of them is that we don’t know what it would mean to make a better baby.”