ѻý

Edit Embryo Genome? Ethics Experts Weigh In

<ѻý class="mpt-content-deck">— You voted, now see the results and expert discussion
MedpageToday

Welcome to Ethics Consult -- an opportunity to discuss, debate (respectfully), and learn together. We select an ethical dilemma in patient care, you vote, and then we present an expert's judgment.

will also be hosting a Twitter Chat with Alyssa Burgart () and Josephine Johnston () on this case on Wednesday, February 19 at 4:00 p.m. ET. To join, follow on Twitter and join the discussion . Use the hashtag #EthicsMPT on all of your tweets; we encourage you to comment, answer questions, ask questions, and react during the chat. Here are the questions we will be discussing:

We've seen a scientist jailed in China for germline editing. With all the hype, what are the most pressing ethical concerns about this technology?

Are some reasons for germline editing more acceptable than others? What reasons for editing are hard to accept?

Would it be acceptable to germline edit embryos if it prevents transmission of a terrible disease?

Would it be acceptable to germline edit embryos if it means not discarding any embryos?

If bans on germline editing were lifted, what could governments, professional societies, and clinicians do to support prospective parents considering using this technology?

Last week, you voted on if it was OK to edit embryo genomes to prevent disease. Here are the results from more than 300 votes:

1. Right now, federal law prevents the FDA from approving any use of germline gene editing, but that law could change. Should it be permissible to edit the DNA of embryos to prevent transmission of a fatal, painful, or burdensome disease?

Yes: 235

No: 87

2. Should the possibility that germline editing could be used for less severe conditions, or even for cosmetic purposes, be a factor in weighing the ethics in cases like the one described here?

Yes: 146

No: 176

And now bioethics experts Alyssa Burgart, MD, MA, and Josephine Johnston weigh in:

Germline editing is one possible application of exciting new genome editing technologies that have the potential to treat and even cure genetic diseases. However, this particular application is also fraught with ethical concerns from uncertainty about its risks and benefits, to debate about its use to alter the future of our species. Germline editing involves editing genes in sperm, eggs, or embryos so that the genetic changes are integrated into every cell in that person's body and can be passed onto future generations.

When evaluating new therapies, it's important to consider the benefits and burdens to individuals, communities, and society. Scientists would presumably use the best science available when selecting gene targets before permanently editing the germline, but it may not be clear whether any such edits have been successful until years later. For adult-onset conditions, the person with the edited genome may pass the edited gene to their own children before being certain it has worked in their own body. Understandably, there is fear that even with the best of intentions, those genome edits will lead to off-target or unanticipated effects in the genome. Germline editing may be the way we find out that a single gene is more powerful than we realized, leading to significant downstream implications. Will edits to the genome lead to previously before unseen cancers or susceptibility to infectious diseases? While these kinds of problems could be terrible if confined to one person, they would be even worse if passed from generation to generation.

When considering germline editing to prevent serious, painful conditions that lead to poor quality of life, it's hard to argue against. Such changes would overall lead to better quality lives for those spared from difficult illnesses. However, many fear that even if genome editing is used early on to prevent disease, that once the techniques are perfected, they will be used to hijack evolution. Powerful, wealthy individuals could use the technology to ensure their offspring have highly desirable traits to get ahead in the world, compared to the population of humans born out of natural pregnancies.

Detractors fear a society like the one depicted in the 1997 film "," where children not created through a eugenics program are unlikely to flourish, and admission to the upper echelons of society pushes families to choose genomic editing. Another set of concerns focus on decision-making processes: When we can potentially change future humans, who gets to decide? What is an equitable, fair approach to that decision? These are important questions to ensure the future human society is one that is better overall, not just better for a few.

At least one population that may push for germline editing are those opposed to the destruction of human embryos. Critics of genome editing for serious illnesses argue that preimplantation genetic diagnosis already solves the issue. However, because it usually involves discarding embryos that have the disease-related gene, PGD may not be a morally permissible option for everyone. For some families, there may be no embryos without the disease gene, meaning that all embryos would be affected. By repairing existing embryos, germline editing could satisfy the moral priorities of patients like the one in our case.

A federal budget rider, first passed in 2015, prohibits the FDA from approving clinical use of germline editing. In addition, the NIH Recombinant DNA Advisory Committee (now retitled NExTRAC) has stated that they will not review germline editing proposals. Recently, international and national organizations have called for stringent criteria to evaluate germline editing but have not recommended banning the technology. Use of germline editing could be permissible if there are no reasonable alternatives, the gene target is clearly implicated in the disease, there is credible data about the risks and benefits, there is a plan for long-term, multigenerational follow up, and continual review of the impact on society. These criteria will present significant challenges to scientists, advocates, and policymakers. Massive commitment to research on early embryonic development and gene editing will only be the beginning of what is required. If scientists and policymakers take up the charge, we may one day have a path towards meaningful, reasoned edits to the human genome.

For more on the ethics of genome editing, check out Josephine Johnston's extensive work on genomic ethics, including her two books: and .

, is assistant professor of anesthesia at the Stanford University School of Medicine and core faculty in the . She is a bioethicist at Stanford Healthcare and Lucile Packard Children's Hospital. is director of research and a research scholar at , an independent bioethics research institute in Garrison, New York. She is a New Zealand-trained lawyer and bioethicist and co-editor of .

And check out some of our past Ethics Consult cases: OK to Give Babies Experimental Drug Not in Trial?, Deaf Couple Only Wants Deaf Baby, and Critical Patient With DNR Tattoo.