What’s So Bad About Editing DNA?

We cannot alter a person’s DNA without disrespecting the intentions of the Author and Creator of human life, Matthew Hennessey recently argued. To support this claim, he offered an account of what it means to be an editor: “When I edit, I attempt, to the extent possible, to conform my work to the author’s original intent. I know I must resist the temptation to rewrite every piece to suit my own ear.” For Hennessey, editing is about improving someone else’s writing, not about the editor exerting his or her own preferences. 

This is a reasonable account of editing; however, it does not serve to condemn the practice of genetic “editing” to which Hennessey is opposed. In fact, the distinction he draws between editing (which respects the author’s intention while improving the piece) and rewriting (which violates authorial intent) can be employed to distinguish those genetic changes which constitute rewriting from those that don’t. As in more mainstream medical practices, something is editing if it is designed to heal a pathology and return an individual to health, and it is rewriting if it is designed to change an individual in some way not ordered to the improvement of an individual’s health. (A treatment designed to cure blindness could be an instance of editing, whereas a treatment designed to replace a visually healthy person’s eyes with the eyes of a hawk would constitute rewriting, and thus a disruption of the authorial intent of the Creator.) It does not matter whether the treatment is genetic or non-genetic, at least with respect to the question of whether it is editing or rewriting. 

Hennessey, though, would claim that DNA is more fundamental than other aspects of what it means to be a person:

There was never a time [my daughter] didn’t have Down syndrome just like there was never a time she didn’t have a mother and a father. In so much as our genetic codes define us, my daughter’s Down syndrome is who she is. She never existed without Down syndrome so there can be no separating her from it. That is, there can be no separating her from it without violating the original intent of the Author.

This argument suggests a wrongheaded way of thinking about DNA, namely that the content of my DNA (in terms of the sequence of letters) essentially defines who I am, and that any alteration to it entails a destruction of my identity. 

A person’ s DNA can change without her identity changing. (A zygote can have DNA which mutates before she becomes a two-celled person.) Two people can have the same DNA without being the same person. (These people are called identical twins.) A person can even have multiple sets of DNA and still be one person. (This occurs in genetic mosaicism, where one cell mutates and reproduces, with the result that some of that person’s tissue has one set of DNA while the rest of her tissue has another set.) In other words, having a particular ordering of Gs, Cs, As, and Ts is neither the necessary nor sufficient condition for a person to be the person she is. 

Moreover, recent work in epigenetics has shown that chromosomal factors other than the DNA sequence can lead to differences in how the genes are expressed. In other words, two people might have a section of DNA with the same sequence of letters, but—due to epigenetic differences—in one person this leads to a particular trait whereas in the other person it doesn’t. It appears that epigenetic changes can be caused by environmental factors, and can be inherited: By undergoing a particular experience a parent can affect how the DNA sequence of a subsequently conceived child will be manifested phenotypically. We do not treat these experiences, which involve the changing of gene expression, to involve a problematic change in identity. Because of this, we also have no reason to suppose that undergoing a change in the content of DNA necessarily involves a problematic change in identity, because both sorts of changes can bring about the same effect in the organism. 

I don’t deny that there are dangers in changing DNA willy nilly. Hennessey is right to be concerned that rewriting will probably occur if it’s technologically possible. There are probably some genetic disorders which can be fixed by changing DNA in a variety of ways, and there would be a strong temptation to edit in such a way as to maximize those trait that was considered socially desirable (like being dark-skinned in some time periods and light-skinned in others). This could lead to abuses similar to those which occur with psychoactive drugs like Adderall: what was designed to treat a disorder ends up being used as an ethically problematic performance enhancer. Ultimately, however, it is not clear that the dangers involved in altering DNA are any different from those involved in medication or organ donation.

Audrey Schaengold graduated from Princeton with a BA in Philosophy, and is currently pursuing a BPhil in philosophy at Oxford.