Gene therapy
Gene therapy

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Gene therapy

5 Designer babies?

A character under genetic influence where the distinction between treatment and enhancement is hard to draw is height. Treatment of short stature – with human growth hormone made in genetically manipulated bacteria – has already given rise to controversy about how short a child needs to be for treatment to count as meeting a medical need. That is, how tall is tall enough?

As we identify genes that have effects on many other human characters, from appearance to, perhaps, intelligence, developing techniques for germline gene therapy could in principle open the way to wider attempts to influence the phenotype of the next generation. Even if experiments in humans are ethically barred, commercial and medical interests are driving the technology forward in animals (remember those genetically modified sheep).

So far, the vast majority of those working with the technology have rejected the idea of germline gene therapy because of fears about ‘designer babies’, as well as wariness of more immediate hazards such as the ones previously outlined (Section 4). In the last few years, though, arguments in favour of permitting some use of germline therapy have been heard more often.


What do you think the argument in favour might be?


Disease alleles would be eliminated.

Although ‘bad’ genes might be eliminated, might ‘good’ genes be added, such as those that contribute to intelligence, appearance or personality? Might the technique lead to the birth of eugenics – the science of improving the human condition through selective breeding – a belief held in the early decades of the 20th century? You might like to think about whether you would vote to permit doctors to alter germline cells by inserting a new gene or genes. And would you change your views if the gene or genes in question gave the resulting baby immunity to HIV, the virus that causes AIDS (acquired immunodeficiency syndrome)?

In the longer term, the advent of reliable techniques for altering human genes could lead to genuinely new ethical problems that are difficult to outline in conventional terms. Most generally, moral philosophers have nearly always argued about justice in terms of inequalities arising from social differences between individuals – such as wealth, class, education and so on. But if we have the ability to alter or ‘correct’ inherited characters, we might have to try to work out a theory of justice that covered what we have always regarded as natural differences between individuals.

Some of these issues have already been raised by recent developments in in vitro fertilization and reproductive technologies, and thus may indicate the kinds of debates that could take place around germline gene therapy. For example, embryos can be tested for genetic conditions, with only those free of affected alleles being implanted into the uterus. This technique can be used to test for diseases such as cystic fibrosis, which have traditionally been seen as obvious candidates for gene therapy. The end result (the removal of that genetic condition from that family) is the same as that produced by gene therapy. If gene therapy is eugenic, then surely the same can be said of such embryo testing which has the added advantage of avoiding the unpredictability of gene insertion (see Section 4). Yet there seems very little public concern about these current reproductive technologies, which may suggest that germline gene therapy may well be acceptable if, or when, it becomes available.

Activity 1: Application of genetic technologies

Click to read the article on 'Selection of the fit and cancer-free [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] '.

Imagine that a friend has just read 'Selection of the fit and cancer-free', and she is puzzled about the meaning of the term ‘designer babies’ because the technology described in some detail in the article is different from the technology described in the section above on this subject. She asks you to write to her explaining, in about 280–300 words, how these two technologies could be used to produce designer babies in the future. You should answer using your own words.

She is familiar with most biological terms (including gene, screening, gene therapy, embryo), so you don’t have to define them. After having considered her question you may decide that you have to explain the meaning of the term ‘designer babies’ and the similarities and the differences in the two technologies outlined in sections 4 and 5 above.

Bear in mind that you should aim for your explanation to be as concise, cohenrent and clear as possible. When you have completed your explanation compare it with the version that we have written in the comments below.


Below is only one possible explanation. In comparing your answer with ours, ensure that you clearly explain the meaning of the term ‘designer babies’ and that you have noted the similarities and the differences in the two technologies (described in sections 4 and 5 and in the article on selection).

Designer babies is a term used to describe babies that have enhanced, or designed, characters as a result of some kind of manipulation. The characters might be increased height, intelligence or appearance. Both the article and the course book link the use of the term ‘designer babies’ to that of in vitro fertilization (IVF), which allows scientists to bring sperm and eggs together to produce an embryo outside of the prospective mother’s body, making them accessible to manipulation by one of two types of technology.

The first technology is screening of IVF embryos (i.e. pre-implantation genetic diagnosis) for the presence of particular characters. One cell can be removed from an early embryo and analysed to see if it carries harmful genes either for a genetic syndrome or associated with cancer. Such embryos would not be chosen for implantation into the potential mother’s uterus. However, embryos could also be checked for the presence of genes that confer cosmetic or enhanced features, and chosen for implantation to produce designer babies.

The other technology which might be used to produce designer babies, is germline gene therapy. Using this technique, the gene(s) can be inserted in the sperm, egg or early embryo whilst the cells are outside the body. The gene(s) are carried by viruses or liposomes into cells. Once here, the gene(s) can become inserted into a chromosome and transmitted to the progeny cells. The inserted gene(s) might correct mutated genes, which is why the technology is being developed, but it might also be chosen to enhance the characters of the future individual.

There are 260 words in the above answer. Explaining terms or phrases like this is a useful exercise because it forces you to think more probingly about the science, and tests that you have understood it.


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