Nearly anything you can measure for humans, he says, can be studied through genetics, and analysing the statistics for huge numbers of people often reveals some genetic component. If the genetic basis of attributes like intelligence and musicality is too thinly spread and unclear to make selection practical, then tweaking by genetic manipulation certainly seems off the menu too. Greely suspects, even if it is used at first only to avoid serious genetic diseases, we need to start thinking hard about the options we might be faced with.
Others doubt that there will be any great demand for embryo selection, especially if genetic forecasts remain sketchy about the most desirable traits. All the same, societies are going to face tough choices about how to regulate an industry that offers PGD with an ever-widening scope.
One of the easiest things to screen for is sex. Gender-specific abortion is formally forbidden in most countries, although it still happens in places such as China and India where there has been a strong cultural preference for boys.
But prohibiting selection by gender is another matter. How could it even be implemented and policed? By creating some kind of quota system? And what would selection against genetic disabilities do to those people who have them? Once selection beyond avoidance of genetic disease becomes an option — and it does seem likely — the ethical and legal aspects are a minefield.
When is it proper for governments to coerce people into, or prohibit them from, particular choices, such as not selecting for a disability? How can one balance individual freedoms and social consequences?
But one must ground government action in a stronger set of concerns about promoting the wellbeing of all individuals while permitting the widest range of personal liberty of conscience and choice. Two technological advances are needed for this to happen, says bioethicist Henry Greely of Stanford University in California.
The production of embryos for IVF must become easier, more abundant and less unpleasant. And gene sequencing must be fast and cheap enough to reveal the traits an embryo will have.
It sounds drastic, but would not be much worse than current egg-extraction and embryo-implantation methods. And it could give access to thousands of eggs for future use. An even more dramatic approach would be to grow eggs from stem cells — the cells from which all other tissue types can be derived. Even mature cells that have advanced beyond the stem-cell stage and become specific tissue types can be returned to a stem-cell-like state by treating them with biological molecules called growth factors.
Last October, a team in Japan reported that they had made mouse eggs this way from skin cells, and fertilised them to create apparently healthy and fertile mouse pups.
Designer babies represent an area within embryology that has not yet become a practical reality, but nonetheless draws out ethical concerns about whether or not it will become necessary to implement limitations regarding designer babies in the future. The prospect of engineering a child with specific traits is not far-fetched.
IVF has become an increasingly common procedure to help couples with infertility problems conceive children, and the practice of IVF confers the ability to pre-select embryos before implantation.
For example, preimplantation genetic diagnosis PGD allows viable embryos to be screened for various genetic traits, such as sex-linked diseases, before implanting them in the mother. Through PGD, physicians can select embryos that are not predisposed to certain genetic conditions. For this reason, PGD is commonly used in medicine when parents carry genes that place their children at risk for serious diseases such as cystic fibrosis or sickle cell anemia.
Present technological capabilities point to PGD as the likely method for selecting traits, since scientists have not established a reliable means of in vivo embryonic gene selection. Some ethical concerns held by opponents of designer babies are related to the social implications of creating children with preferred traits.
The social argument against designer babies is that if this technology becomes a realistic and accessible medical practice, then it would create a division between those that can afford the service and those that cannot.
Therefore, the wealthy would be able to afford the selection of desirable traits in their offspring, while those of lower socioeconomic standing would not be able to access the same options. As a result, economic divisions may grow into genetic divisions, with social distinctions delineating enhanced individuals from unenhanced individuals. However, data submitted as part of the trial listing shows that genetic tests have been carried out on fetuses as late as 24 weeks, or six months.
He also released a promotional video about his project. The birth of the first genetically tailored humans would be a stunning medical achievement, for both He and China. But it will prove controversial, too. Where some see a new form of medicine that eliminates genetic disease, others see a slippery slope to enhancements, designer babies, and a new form of eugenics.
The step toward genetically tailored humans was undertaken in secrecy and with the clear ambition of a stunning medical first. The purpose of the international meeting is to help determine whether humans should begin to genetically modify themselves, and if so, how. The technology is ethically charged because changes to an embryo would be inherited by future generations and could eventually affect the entire gene pool.
The genetic editing of a speck-size human embryo carries significant risks, including the risks of introducing unwanted mutations or yielding a baby whose body is composed of some edited and some unedited cells.
In a scientific presentation in at Cold Spring Harbor Laboratory, which is posted to YouTube , He described a very large series of preliminary experiments on mice, monkeys, and more than human embryos. But He claimed he found few or no unwanted changes in the test embryos. A new breed of biotech companies could ultimately reap a windfall should the new methods of conferring health benefits on children be widely employed. According to the clinical trial plan, genetic measurements would be carried out on embryos and would continue during pregnancy to check on the status of the fetuses.
A listing describing the study was posted in November, but other trial documents are dated as early as March of That was only a month after the National Academy of Sciences in the US gave guarded support for gene-edited babies, although only if they could be created safely and under strict oversight.
Currently, using a genetically engineered embryo to establish a pregnancy would be illegal in much of Europe and prohibited in the United States. It is also prohibited in China under a ministerial guidance to IVF clinics. It is not clear if He got special permission or disregarded the guidance, which may not have the force of law. In recent weeks, He has begun an active outreach campaign, speaking to ethics advisors, commissioning an opinion poll in China, and hiring an American public-relations professional, Ryan Ferrell.
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