First-Ever Gene Editing Inside Body Raises Questions About Future of Human Species

By Kevin Hogan

NEW YORK—The genetics revolution has begun as scientists now have the ability to “hack the code of all of life, including our own” by manipulating the DNA that makes up the very foundation of our being, according to genome editing expert Jamie Metzl.

Scientists two weeks ago altered the DNA of a patient inside the body for the first time, which is different from therapies used in the last few years where genes are edited outside the body. The procedure comes after a Chinese scientist, He Jiankui, was imprisoned in December for making gene-edited babies in 2018.

Metzl, who is an adviser to the World Health Organization’s committee on human genome editing and the author of the book “Hacking Darwin,” says there needs to be a society-wide discussion on the use of gene editing technology.

“We have to be part of that conversation, but to be part of it, everybody has to be educated because what we’re talking about is, in many ways, the future of our species,” Metzl told NTD.

Scientists performed the first procedure to edit a patient’s genes inside the body, or “in vivo,” at the Casey Eye Institute in Portland, Oregon, on March 4. They treated a patient, who has a rare form of inherited blindness, with a gene editing tool known as CRISPR in an attempt to restore the patient’s vision.

The tool, CRISPR, is likened to a pair of molecular scissors that are able to cut strands of DNA. The tool was developed by mimicking the natural defense mechanisms of bacteria.

This technology allows for a shift in the way health care is delivered, from a generalized approach to one specific to the individual, according to Metzl.

“Now we’re moving to this world of precision medicine and precision healthcare, where decisions will be made not just based on the fact that you’re a human, but based on the fact that you are you,” said Metzl.

He predicts that billions of people will have their entire genomes sequenced in the future.

“We’ll have these massive genetic databases, and what are called phenotypic information in those databases, which is your life and health records,” Metzl said. “And we put those together, we’re going to use big data analytic tools that will transfer us from this world of precision health care, to predictive health care.”

The paradox is that for these predictive methods to be useful, large genetic databases are needed, but it’s important for individuals to be able to keep their genetic information private, according to Metzl.

“I think people are nervous and should be nervous, and we need more regulation. But we can’t go all the way toward complete privacy,” Metzl said.

Privacy isn’t the only concern surrounding gene editing technology—accidental changes to the DNA may occur and that can be passed down to future generations.

There are two types of gene editing: somatic and germline. Somatic edits are done on cells that are not part of the reproductive system and are not meant to be passed down. While germline edits to eggs, sperm, and embryos lead to heritable genetic changes.

According to bioethicist Barbara Koenig, if a mistake is made in germline editing, “it will be a mistake for all future generations.” There is concern that once the damage is done, it may be irreversible. Koenig also says “that somatic edits could have off target effects on egg or sperm.”

If scientists perform a somatic edit in which unintentional changes occur in the sex cells, then it would be passed on, according to Metzl.

Metzl highlights the benefits to this technology, but recognizes the need for caution if it is used.

“We don’t understand the vast majority of [our genetics], but we will understand more and more and that will give us greater opportunities to intervene in ways that can protect us. But because of the incredible complexity of biology, we need to be very cautious and careful and conservative when doing so,” he said.

Gene editing is not the only way in which human DNA is artificially manipulated. Clinics offer services where multiple eggs are fertilized in a lab and turned into embryos that are then screened for genetic defects. One of the embryos free from genetic diseases is then implanted into the mother to be a future child.

When conception is carried out in a laboratory it is called “in vitro fertilization” or IVF. The procedure for screening the DNA of the embryos for genetic defects is called “pre-implantation genetic diagnosis” or PGD.

Metzl predicts that if stem cells become safe for human use, it will be possible to create 10,000 human embryos and select one of them to implant into the mother. He says we may make a small number of changes to the DNA of the selected embryo to reduce health risks or enhance certain traits.

Within 10 years, this technology may be advanced enough to change a person’s eye color by editing the genes of the embryo, according to Metzl.

The Catholic Church disapproves of in vitro fertilization, and any procedure that comes of it such as PGD or editing the genes of embryos.

“The separation of procreation from a sexual act in any way that that’s done is disapproved,” said Edward Mechmann, who is an attorney with the Roman Catholic Archdiocese in New York. He said conception should be the result of an act of love between a husband and wife, not a scientific act.

“One of the key things is we very much disapprove of a kind of eugenic mentality where they’re using any kind of gene editing to enhance characteristics,” Mechmann said.

Metzl described a scenario in which this technology is developed and falls into the wrong hands.

“You could imagine a kind of a North Korea-like regime that says, well, first we’re going to sort people, we’re going to sequence everybody at birth, and we’re going to sort them based on our sense of what’s their capacity. So who gets to be in the military and who goes to the Olympic programs and who goes to physics school,” Metzl said. “I think that will certainly be doable.”

“You could imagine those kinds of selections being made for docility in some kind of totalitarian state,” he added.

A potential problem with this type of artificial gene selection is that if parents choose similar traits for their children “we could inadvertently reduce the genetic diversity of our species,” Metzl said. “That genetic diversity—it’s not a nice to have, it’s a need to have. It’s the foundation of our survival. It translates into our resilience.”

Metzl said that everyone needs to talk to their elected officials and ask them to focus on this important issue. He said one must ask if officials have a plan in place and ask how they will maximize the benefits and minimize the harms of this technology.

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