As the science behind genetic engineering and gene therapy has evolved in recent years scientists, ethicists and legislators have worked to set limits to the research. One critical line in the sand has been a consensus, endorsed by ethics councils and even a legally binding Council of Europe convention signed by 40 states (though not Ireland), that interference with, or “editing”, of human eggs, sperm or embryos to create genetic traits that can be inherited by future generations, so-called germ line engineering, has been strictly taboo.
The idea of human intervention in our own evolution rang alarm bells, conjuring up dystopian fears of scientists in their labs breeding a super-race or cosmetically engineering traits like strength, beauty and intelligence. The commercial opportunities are mind-boggling... but the technology simply did not allow it and so the line in the sand was largely academic.
Not so anymore. Recent advances, notably a powerful gene-editing tool called Crispr, have made snipping out tageted parts of the DNA of germline and non-germline, “somatic”, genes a relatively simple process. And the ethical debate has reopened. A report this week from two high level US scientific bodies US argues that germline editing should be allowed in very limited circumstances under strict supervision – only alterations designed to prevent babies from acquiring genes known to cause “serious diseases and disability”, and only when there is no “reasonable alternative.”
If , for example, it were to become possible to “edit” the genes of someone with Huntington’s, a dreadful, incurable, inherited brain disease, so that the condition could not be passed on to successive generations, why not? How would that be qualitatively different ethically from the somatic gene therapy already widely practised?
In theory, that is. However there will be a particularly tough onus on researchers to show that the techniques when applied to the germline can be perfected to the point where such “snipping” does not involve “off-target” parts of the DNA or produce other consequences unrelated to this pupose in subsequent generations. We must hasten slowly.