Is Silence Consent?

On August 13, 2018, Molecular Therapy published a report (Open Access) that explicitly “suggests the efficiency and genetic safety of correcting a Marfan syndrome (MFS) pathogenic mutation in embryos by base editing.” That is, another step toward the plausible possibility of germline intervention: heritable human genetic modification.

You’d think this would be a big deal. After all, the Nuffield Council in the UK just published a 200-page evaluation of possible germline intervention, treating it as a future possibility that demands ethical consideration now. In November, in Hong Kong, the Academy of Sciences of Hong Kong, the U.S. National Academies and the British Royal Society will host the Second International Summit on Human Genome Editing: “Of particular concern is the possibility of heritable genome editing, which would alter the human germline, and applications for purposes other than to treat disease or disability.”

But there has been very little reaction to this paper. Perhaps it’s hard to keep up: Advances in embryo editing in recent years have indeed been incremental — but also rapid. In 2015 a report was published about the attempted use of CRISPR/Cas9 on non-viable embryos, targeting β-thalassaemia; the authors stressed “the pressing need to further improve the fidelity and specificity of the CRISPR/Cas9 platform, a prerequisite for any clinical applications of CRISPR/Cas9-mediated editing.”

Further publications in 2016 and 2017 (1, 2, 3, 4) from Chinese, American and British teams advanced research into embryo editing; a 2017 paper by Li et al, published online in August, has a summary. Then in September 2017, Liang et al. published a paper about base editing of β-thalessemia in cloned human embryos, which concluded:

Collectively, this study demonstrated the feasibility of curing genetic disease in human somatic cells and embryos by base editor system.

The latest report is a significant further step in this direction. But when it came out, there seems to have been no reaction for a week, until on August 20 Sharon Begley wrote it up in STAT:

Newest form of CRISPR corrects genetic disease in viable human embryos, with few errors

Science then added a brief note that cited STAT, as did Wired, which published a substantial report the next day, by Megan Molteni. And that was about it. BioNews and Singularity Hub had reports a week later. CRISPR News tweeted on the 24th (138 retweets, 186 likes from 15.9K followers), picked up by Noah Smith on the 31st (25 retweets, 95 likes from 110K followers).

A series of searches on September 2 turned up no mention of the publication (or of course its implications) in: The New York Times, Washington Post, San Francisco Chronicle, Guardian, Independent, AP, Reuters, Nature, Scientific American or even the Marfan Foundation!

Nor, therefore, were there publicized caveats and critiques, even in STAT and Wired, and despite the fact that the authors open their paper with an explicit endorsement of using germline editing in human reproduction. (Previous authors have generally not been explicit about their goals.)

Aside from general objections to heritable human genetic interventions, this particular paper calls for several specific comments. For example:

• An existing embryo screening technique called Preimplantation Genetic Diagnosis (PGD) can effectively prevent the transmission of the allele involved in Marfan Syndrome; 50% of embryos will be unaffected.
• Nowadays, people with Marfan Syndrome can be treated and “have a life expectancy similar to that of the average person.”
• Moreover, some patients only have mild symptoms.
• And even if this technique were to be put into practice, it would presumably come at enormous expense.

Even the journal article admits that PGD “is useful to prevent the generational transmission of the mutant allele to embryos,” but suggests there is a “potential risk for diagnostic errors” while the process described “potentially provides an active approach for correcting the genetic diseases.” Actually, their experiments had an 89% success rate, which is good but hardly perfect; that implies its own potential risk for diagnostic errors.

Technically, the scientists seem to be competent. And there is no value in “blaming China” for lack of regulation (as some on Twitter already have): The Ethics Committee of the Third Affiliated Hospital of Guangzhou Medical University approved the study. The eggs used were left over from fertility treatment and knowingly donated, as were the sperm and blood samples (apparently only one male patient was involved). And no attempt was made to induce a pregnancy.

But where is the ethical discussion about what they are trying to do? Sharon Begley, in STAT, at least mentioned the question:

Such “germline editing” used to be an ethical red line, but in recent months more and more ethicists and scientists have concluded that it would be an acceptable use of reproductive technologies if it can prevent or alleviate human suffering.

This seems inaccurate to me. The debate about germline intervention has always been two-sided. Those who have publicly “concluded” that it would be “acceptable” are mostly, if not entirely, those who always thought that. Shouting louder than your opponent does not mean you win a debate. But you may intimidate people into keeping quiet.

If something happens and no one talks about it, does that mean it is accepted? Has germline gene editing been normalized before it even exists? What will November’s Summit really be about? Will the only “legitimate” discussion be about the distinction between medical treatments and enhancement technologies?

And is silence consent?