No to genetic engineering of humans!

David King

From GenEthics News issue 9

One of the recurrent horror scenarios of genetic engineering is the creation of armies of engineered blond 'super-soldiers'. As geneticists are often at pains to point out, we are very far from realising such a scenario. It does not seem necessary to explain why the attempt to create 'super races' is undesirable, but there are already many people arguing that genetic engineering of humans could be used for medical benefit. At present the technology does exists to introduce genes into human cells, and a massive industry is being created around the still very experimental technology of gene therapy. So far, only somatic cells (body cells other than the 'germ line' - the cells that give rise to sperm and eggs) have been manipulated in this way in humans. But in animals, engineering of the germ line, to create transgenic animals, particularly mice, is commonplace (see GEN5, p5). In Britain, the Human Fertilisation and Embryology Act prohibits genetic engineering of human embryos, after fertilisation, but is silent on attempts to engineer eggs and sperm.

With some exceptions, the current consensus in the medical and scientific world seems to be that germ line engineering (GLE) should not be permitted at present, for reasons of safety. It is impossible to guarantee that such manipulation would not itself have harmful effects on the child. The primary danger arises from the fact that new DNA integrates randomly into chromosomes: in doing so it may 'land' in the middle of vital genes, causing mutations which may be harmful or lethal. There is a large catalogue of such unexpected and sometimes horrific mutations in transgenic mice. Until some way is found of controlling the integration of DNA into chromosomes, it is unlikely that human germ line engineering will be officially sanctioned. Nonetheless, there seems to be a widespread expectation that it will be technically and ethically possible to create a reliable GLE system. The objection on the grounds of safety is entirely different from a principled objection to GLE as such.

What for?

One of the flaws in the argument of those who support the possibility of GLE for medical purposes is that there seem to be very few good examples where it is the only solution to the medical problem of genetic disease. The main advantage of GLE is said to be the elimination of disease genes from a family. This must surely refer to 'dominant' disease genes where even if only one copy is present disease will occur. There is no medical benefit to a family from eliminating 'recessive' genes like the cystic fibrosis (CF) gene which do not cause disease when only one of the two copies is harmful. In this case, existing technologies of prenatal and preimplantation testing allow the avoidance of actual disease, so the benefit of eliminating the CF gene would be purely psychological: not having to worry about CF anymore. Such psychological benefits surely do not justify GLE. In fact, even in the case of dominant genes, prenatal screening is only inadequate to guarantee the birth of an unaffected child in the very rare case where one partner has two copies of the dominant, disease causing gene. Other proposed candidates for GLE are likewise extremely rare.

Furthermore, there is always another solution for those couples who are certain to produce a genetically disabled child and cannot, or do not want to deal with this possibility. They can choose not to have children, or to adopt a child. Parenthood is not the only way to create fulfilment through close, intimate and long lasting relationships with children. Although this may be an inferior solution for some, the question we have to ask is whether this rather minor and rare consideration justifies developing the technology for GLE, with all the incalculable consequences that may flow from it. We have become too used to the assumption that people's desires for a child, come before the needs of society's at large.

Given the lack of good candidates for GLE on medical grounds, one is tempted to question the insistence on the part of many doctors and geneticists that GLE should not be banned indefinitely. Assuming that such individuals are not using purported medical benefits as a cover for an urge to indulge in cosmetic or 'enhancement' engineering, it seems most likely that the driving force is blind technophilia, or the desire to wield the awesome power that GLE would bring.

Can we control it?

Germ line manipulation opens up, for the first time in human history, the possibility of consciously designing human beings, in a myriad of different ways. I am not generally happy about using the concept of playing God, but it is difficult to avoid in this case. The advocates of genetic engineering point out that humans constantly 'play God', in a sense, by interfering with nature. Yet the environmental crisis has forced us to realise that many of the ways we already do this are not wise, destroy the environment and cannot be sustained.

Once it was available, how would it be possible to ensure that GLE was used for purely medical purposes? The same problem applies to prenatal genetic screening and to somatic gene therapy, and not only are there no accepted criteria for deciding what constitutes a medical condition, but in a free market society there seems to be no convincing mechanism for arriving at such decision. The best answer that conventional medical ethics seems to have is to 'leave it up to the parents'.

As a result of the free market, sophisticated medical technology and medical personnel are employed in increasingly fashionable cosmetic surgery; and at the same time, due to aggressive marketing by its makers, genetically engineered human growth hormone, developed to remedy the medical condition of growth hormone deficiency, is routinely prescribed in the USA to normal short children with no hormone deficiency. If these pressures already exist, how much stronger will they be for a technology with as great a power to manipulate human life as GLE? And of course, once the technology was described in the scientific literature, it would be possible for, for example, dictators to abuse it, with horrific consequences.

In short, the world is not a safe enough place to let this particular genie out of its bottle and it would be irresponsible in the extreme to do so. This does not imply an absolutist opposition to genetic engineering. It should be clear from many articles in GenEthics News that I am not opposed to genetic engineering per se. However, there are some aspects of genetic engineering, the comsequences of which are far too dangerous to contemplate. This is one of them.