About a year ago we had some discussions on the three-parent baby, involving the use of healthy mitochondria from a donor. And today we see creeping into the press a new word to us: CRISPR (clustered regularly interspaced short palindromic repeats). This is proving to be an efficient method of editing genes. It may knock three-parent babies into a cocked hat. And we ought to be aware of it. Although gene editing is already possible, it has been a slow and tricky process. By contrast, the CRISPR methodology is speedy and cheap; in effect, the process has been automated. Consequently many research laboratories across the world are racing to refine its use and to discover further applications. We do not know where they will get by the end of this year, let alone over the next decade.
In summary, the method involves the use of a (RNA) guided protein to search out specific sequences of DNA, and snip them out with molecular blades. Repair proteins automatically fill the gap and, if required, insert new genetic sequences programmed by the experimenter. The theory is simple but much research is being done to achieve greater levels of accuracy. If you need a more detailed description, hasten to the internet where you may decide that my basic description is enough for the time being.
The ability to identify and prune genes so speedily brings an immediate advantage. Geneticists work hard to link specific genes to a specific characteristic. CRISPR is a huge step in this direction. It will enable us to study the human organism in its causes and effects comprehensively and in an altogether shorter timescale. About 60,000 diseases are caused by genetic mutations, as yet we can treat only about five percent. The facility to locate and replace genes and so cure many damaging disabilities is one which, in principle, we should see as a blessing. However there is a shadow. Although much experimental work is done on the lower animals it is ultimately necessary to use human cells, including non-viable embryos, and the rejected products of in vitro fertilisation.
Deeper still is the tricky area of germline editing – that is, altering DNA which will be inherited by progeny. Humans have proved exceedingly complex, and some influential scientists argue that there should be a moratorium in this field until the necessary knowledge has been achieved. But this is an international race and it is well-nigh impossible to exercise effective control. Apart from the personal values of experimenters, the financial and reputational rewards of developing methodologies are potentially huge. We must be pessimistic. The slippery slope is not in prospect, we are already sliding down it. This month our own authority (HFEA) has provisionally approved gene editing with CRISPR for an embryo under seven days, prior to destruction.
At the end of 2015 an international conference of scientists debated the question. It did not recommend that experimental research should cease, but that we should “refrain from research and applications that use modified human embryos to establish a pregnancy” until the issues of ethics and safety had been resolved. They were much moved by the mother of a child, dead from genetic disease, who said “If you have the skills and the knowledge to fix these diseases, then frickin’ do it.”
And we agree. Prescinding from the research methodology, we are naturally in favour of correcting faulty genes which would lead, say, to avoiding sickle celled anaemia or Down’s syndrome, providing that this can be achieved safely, and with no unacceptable side effects. But we do not know, for example, what the ultimate effect on the germline will be. It is one thing to experiment with animals, and another to experiment with human beings and their post factum progeny.
We distinguish between an action taken to heal damage and an action, however well intended, taken to alter the personality or characteristics of the embryo. The picture of a parent producing a shopping list for high intelligence, longevity, personality, blonde hair and the rest is grotesque. Yet, in principle all this could be achieved with the help of CRISPR, even though the dividing line between damage correction and improvement is problematic. If human beings can be tailor-made, they will be. I wonder whether we will do a better job than the Almighty.
You think that’s all? Work currently being done on primordial germ cells, which can be developed into sperm and eggs, suggests that the whole process of conception, starting from a skin cell, could one day be completed in a dish, and the result, equipped with custom DNA, implanted in a womb. Though, by then, the womb, which leaves so much to chance, may already be old technology. If that doesn’t remind you of Brave New World, I don’t know what will.