Dramatic developments in genetic technology have enormous potential for human health, but the heated debate this technology causes goes beyond safety and into moral arguments, writes Russell Blackford.

CRISPR-Cas9 is a dramatic development in genetic technology. It is a powerful, relatively simple, and increasingly precise technique for editing the DNA of living organisms. Its potential application to human beings was highlighted in April 2015, when researchers in China reported their experiments on non-viable human zygotes.

The paper by Puping Liang and others was published in the scientific journal Protein & Cell. It describes the difficulties encountered, and draws a plainly reasonable conclusion: more research is needed before attempting clinical applications of CRISPR-Cas9. That noted, the precision of gene-editing techniques is now advancing rapidly.

At some point, treatments employing CRISPR-Cas9 modifications to ordinary human cells will become available to adults and children with genetic problems. In principle, however, modifying the DNA of early embryos or germ cells is a more straightforward and powerful application of the technology. Should we go so far?

We currently use pre-implantation genetic diagnosis (PGD) during in-vitro fertilisation for a range of cases where parents are at risk of producing a child with the potential for serious disease. That is, we can select embryos lacking the culprit genetic variant. In some situations, however, this is not an adequate solution. In an article recently published in Nature, George Church, a professor of genetics at Harvard Medical School, observes that PGD “does not offer a solution for someone who has two copies of a deleterious, dominant version of a gene nor for potential parents who both have two copies of a harmful, recessive version of a gene.”

Some of the debate over gene-editing technology – like the older debate over human cloning sparked by the creation of Dolly the sheep nearly two decades ago – involves issues of efficacy and safety. In both cases, however, the dominant voices are often those pushing quasi-religious moral theories (about playing God, violating nature or human dignity, and so on) or engaged in dystopian fear-mongering.

The fear-mongers predict the emergence of a genetic caste society, and surely that would be a bad outcome. However, it’s a remote and speculative possibility that we can largely set aside in current policy deliberations.

Realistically, we have no foreseeable prospect of enhancing beneficial traits such as intelligence through genetic science. Indeed, human gene interactions are so complex and daunting that the level of technology required for such innovations as cognitive enhancement may lie indefinitely beyond our grasp. As far as we can predict, the genetic editing of human germ cells and embryos, even for experimental purposes, is likely to concentrate on attempting to restore a single gene, or perhaps a very small combination of genes, from a diseased state to what is considered normal.

Nonetheless, concerns about possible uses for CRISPR-Cas9 prompted a high-level conference, the International Summit on Human Gene Editing, in Washington DC during the first week of December. On 3 December 2015, the conference’s organising committee released its International Summit Statement on gene editing research and practice.

Considering the heat surrounding the issue, this statement is commendably measured and cautious. It gives a green light to further research, but warns against using techniques such as CRISPR-Cas9 to bring genetically modified babies into the world. Researchers should draw the line at creating pregnancies until we have a much better guarantee of safety, together with “appropriate regulatory oversight.” No serious commentator should disagree with that.

More worryingly, however, the statement claims that it would be irresponsible to proceed with clinical use of germline editing until “there is broad societal consensus about the appropriateness of the proposed application.”

This is far too conservative.

There are political and social risks whenever governments, institutions, or individuals act in opposition to public opinion. All the same, we’re not required to gain a societal consensus for everything we propose to do. For example, there is no such consensus on the acceptability of abortion, but that’s not a reason to ban it or to label medical practitioners who conduct abortions as irresponsible. At the level of government action, any ban would need to be justified by compelling arguments. It might need to be shown that fetuses and even early embryos have rights that ought to be protected by the state.

More generally, democracy is valuable in providing a peaceful means to replace corrupt, incompetent, or oppressive governments. It does not mean, however, that we must always bow to the opinion of the majority, let alone to the veto of an influential minority whose viewpoint prevents societal consensus.

Much as we might worry about ruthless, Frankensteinian medical researchers, there is also a problem of bioethical overregulation with the potential to delay vital therapies. Overall, the Washington summit statement strikes a fair balance, but we should beware of the tyranny of mere public opinion.