Interview questions from the French Weekly Le Point
In your opinion, when Germline engineering will be a realistic option?
Gregory Stock: Several technologies have to mature before human germline engineering will be feasible, but we will be getting close within two decades. At present, there is neither a safe method of doing such manipulations in humans, nor anything worth doing. As to the first, current techniques used in human somatic therapy or germline manipulations of animals are unlikely ever to be safe or reliable enough for human germline use, but artificial chromosome technology looks promosing and could easily mature within a decade or so. As to the second, we simply do not yet know enough about how various constellations of genes influence human traits and predispositions to have compelling targets for germline interventions at present. The progress that will flow from the Human Genome Project over the next decade, however, is likely to change that.
Therapies for single-gene disorders are unlikely ever to be targets for germline manipulation, not because they won't be feasible, but because preimplantation genetic diagnosis and embryo selection will let us avoid these conditions so much more easily. Germline likely will have to wait for polygenic manipulations that bring therapeutic enhancements -- increased lifespan, for instance.
Some scientists think that our genome is too complex ever to modify meaningfully in this way. It think they are deceiving themselves. Some interventions will be far too complex to achieve, others will be just plain hard, and still others are likely to be surprisingly easy. The next decade will give us a good indication of which human interventions fall into which categories.
How far the technology might advance within two decades?
G
regory Stock: Within two decades, four foundational developments will probably have occurred. Human artificial chromosomes will likely be adequately developed to carry into human cells modules of genes and the control sequences to manage their expression. IVF will likely have improved sufficiently to be a relatively straightforward process as opposed to the miserable procedure it is today. PGD will be very sophisticated and will allow embryos to be checked for many genetic vulnerabilities and predispositions. And the work emerging from the Human Genome Project will likely have unravelled aspects of human phsyiology and behavior that will provide interesting targets for germline enhancement. Some say these developments will take longer, but this is quibbling. It does not change the big picture, which is an amazing one. In a few decades -- a mere instant in the larger scheme of our evolution -- human reproduction will begin to shift significantly and we will begin to control our own evolutionary future.
Some people think that germline intervention violates the sanctity of the
human gene pool and our"right" to an unaltered genetic inheritance. What do
you think about?
Gregory Stock: This "sanctity" is essentially a religious view, and as such, it is not something that people look at with a very open mind. It is also closely tied to the idea of "genetic patrimony," the concept that the gene pool is somehow a collective asset of humanity that is worthy of social protection. This all sounds responsible and caring, but it makes no sense. First, the gene pool is not a thing. It is the totality of all of our genes, and we change it all the time. Every time we use antibiotics to save some child and let him or her grow up and have children, we are changing the gene pool. Every time we improve public health and reduce deaths from disease we change our gene pool. Everytime we use contraceptives we change it. Every time we send relief to a country in need, we change the gene pool.
Moreover, for genetic selection and genetic manipulation to have any meaningful impact on the constitution of the gene pool as a whole, these technologies would have to be so widely embraced by the world's population, that it is not worth worrying about. If this occurs, it will be because there are benefits so compelling that no one can resist them. If you want to protect the human gene pool, you would be far better off to try to outlaw contraceptives, war, and modern medicine then worry about germline technology.
As to the "right," to an unaltered genetic heritage, who makes up these "rights," anyway? Genetics and evolution can be downright cruel. Of course, we want to protect our future children from diseases and genetic vulnerabilities. It is incomprehensible to me that parents would really decide to let their children have diabetes or Tay Sachs and then tell them that we easily could have prevented it but didn't want to interfere with their right to an unaltered genetic constitution.
What is your opinion on the ethics and medical risks of the germline
approaches ?
Gregory Stock: I think that the ethical choice we face today is not whether we should let this happen or not? It is going to happen. The real question is how it will happen, who will have access to these technologies, and how much this development will divide us one from another. These are the questions we should be looking at, and many approaches would likely lead to much better outcomes than today's attempts to ban these future technologies. The French and German approach is short-sighted. It essentially passes off the development of these potent technologies to those in other regions of the world, so that Europe will have no voice in their development. And should these restrictions remain when the technologies finally arrive, such policies will simply drive the procedures underground and reserve them for the affluent, who will circumvent any such laws if the technologies seem useful. Embryo testing, for example, is illegal in Germany, so any German who wants it and can afford it just goes to London.
Is it true that when you posed a question to the 750 attendees at our
symposium in Los Angeles: "Imagine you're conceiving a child by in-vitro
fertilization, and your obstetrician says that the embryo of that
child-to-be could without additional risk be given an artificial chromosome
to increase his or her life expectancy by a decade. Would you use the
procedure?" Nine out of ten said yes ?
Gregory Stock: Yes, I posed the question, but somewhat less than two-thirds said yes. This is in line with international polls on the issue. The ethicist Daryl Macer polled people in 8 countries (none European) about whether they would use a safe genetic intervention to enhance the physical or intellectual attributes of their children-to-be. The percentage who said they would do so ranged from 22 % in Israel to over 80 % in India and Thailand. The US was at 44%. This broad support is one of the reasons that germline technology eventually will arrive. Another is that no one needs to work on the technology; it will be a mere spinoff of mainstream biomedical research that we all support. Moreover, such technology will one day be feasible in thousands of laboratories throughout the world. Borders are too permeable in the modern world for it ever to be effectively policed without nightmarish totalitarian methods.