Professor Stephen Hawking has pleaded with world leaders to keep technology under control before it destroys humanity.
venerdì 20 marzo 2015
Stop Genetically Altered Children
Nobel Prize winners raise alarm over genetic engineering of humans
A group of senior American scientists and ethics experts is calling for debate on the gene-engineering of humans, warning that technology able to change the DNA of future generations is now “imminent”.
In policy recommendations published today in the journalScience, eighteen researchers, including two Nobel Prize winners, say scientists should accept a self-imposed moratorium on any attempt to create genetically altered children until the safety and medical reasons for such a step can be better understood.
The concern is over a rapidly advancing gene-editing technology, called CRISPR-Cas9, which is giving scientists the ability to easily alter the genome of living cells and animals (see “Genome Surgery”). The same technology could let scientists correct DNA letters in a human embryo or egg cell, for instance to create children free of certain disease-causing genes, or perhaps with improved genetics.
“What we are trying to do is to alert people to the fact that this is now easy,” says David Baltimore, a Nobel Prize winner and former president of Caltech, and an author of the letter. “We can’t use the cover we did previously, which is that it was so difficult that no one was going to do it.”
Many countries already ban “germ line” engineering—or changing genes in a way that would be heritable from one generation to the next—on ethical or safety grounds. Others, like the U.S., have strict regulations that would delay the creation of gene-edited children for years, if not decades. But some countries have weak rules, or none at all, and Baltimore said a reason scientists were speaking publicly now was to “keep people from doing anything crazy.”
The advent of CRISPR is raising social questions of a kind not confronted since the 1970s, when the ability to change DNA in microӧrganisms was first developed. In a now famous meeting in 1975, in Asilomar, California, researchers agreed to avoid certain kinds of experiments that were then deemed dangerous. Baltimore, who was one of the organizers of the Asilomar meeting, says the scientists behind the letter want to offer similar guidance for gene-engineered babies.
Since then, several teams of researchers in China, the U.S., and the U.K. have begun using CRISPR to change the DNA of human embryos, eggs, and sperm cells, with an eye toward applying the technology at in vitro fertility (IVF) clinics. That laboratory research was described by MIT Technology Review earlier this month (see “Engineering the Perfect Baby”).
But that position was rejected by the authors of the current Science editorial. Instead, they said basic research on germ line engineering should move forward, including efforts to determine “what clinical applications, if any, might in the future be deemed permissible.”
Today’s statement was organized by Jennifer Doudna, a University of California, Berkeley, biologist who codiscovered the CRISPR technology. She confirmed that the group supports using it to edit the DNA of early-stage human embryos if it’s for scientific research.
That recommendation could come as a bombshell to critics of germ line engineering, as well as religious groups. Some believe an ethical “bright line” should separate humanity from the kind of gene-tinkering used on plants, microbes, and animals. If so, what is the point of testing the technology in human embryos?
But some authors of the Science editorial believe basic research must be given a free hand. “Science should not be impeded in its earliest stages by concerns that improvements in, and validations of, certain parts of the technology are opening the door to eugenics,” says Paul Berg, a professor emeritus at Stanford’s medical school, who also signed the letter. Berg said he supported research aimed at “perfecting the technology in preparation for the time when society could sanction germ line modification in medicine.”
A growing industry has already sprung up around gene editing, which is being applied to lab animals and farm species, and is being contemplated as a way to treat adults with diseases like muscular dystrophy or HIV infection. Such treatments of sick individuals are known as somatic gene therapy, and were not the subject the current editorial, or the call for a moratorium.
Theoretically, germ line editing could correct genes that lead to lethal diseases before birth. For instance, if a person had Huntington’s disease, caused by a single faulty gene, CRISPR could be used to eliminate the mutation from that person’s children.
One biotechnology company,OvaScienceof Cambridge, Massachusetts, has invested more than $2 million dollars investigating whether gene-editing could be used in IVF procedures. OvaScience did not respond to a request for comment.
While correcting inherited disease genes could prove medically useful, the authors of the Science editorial said much remained unknown. “Even this seemingly straightforward scenario raises serious concerns,” they said of editing disease genes back to their healthy form. That is because scientists are unable to predict all the consequences of changing DNA letters in a person, especially if multiple genes were corrected at once.
“You would be making changes in generations to come, in ways that are very hard to predict,” says Baltimore.
In their editorial, the researchers call for high-level technical forums to discuss CRISPR, as well as convening a “globally representative” group of government agencies, ethics experts, and scientists to recommend policies. In the meantime, they say, scientists must refrain from actually producing genetically engineered babies, even though the opportunity to do so now exists.
“Scientists should avoid even attempting, in lax jurisdictions, germline genome modification for clinical applications in humans,” they write.
The world’s first genetically modified humans have been created.
The disclosure that 30 healthy babies were born after a series of experiments in the United States provoked another furious debate about ethics.
So far, two of the babies have been tested and have been found to contain genes from three ‘parents’.
Fifteen of the children were born in the past three years as a result of one experimental programme at the Institute for Reproductive Medicine and Science of St Barnabas in New Jersey.
The babies were born to women who had problems conceiving. Extra genes from a female donor were inserted into their eggs before they were fertilised in an attempt to enable them to conceive.
Genetic fingerprint tests on two one-year-old children confirm that they have inherited DNA from three adults –two women and one man.
The fact that the children have inherited the extra genes and incorporated them into their ‘germline’ means that they will, in turn, be able to pass them on to their own offspring.
Altering the human germline – in effect tinkering with the very make-up of our species – is a technique shunned by the vast majority of the world’s scientists.
Geneticists fear that one day this method could be used to create new races of humans with extra, desired characteristics such as strength or high intelligence.
Writing in the journal Human Reproduction, the researchers, led by fertility pioneer Professor Jacques Cohen, say that this ‘is the first case of human germline genetic modification resulting in normal healthy children’.
Some experts severely criticised the experiments. Lord Winston, of the Hammersmith Hospital in West London, told the BBC yesterday: ‘Regarding the treat-ment of the infertile, there is no evidence that this technique is worth doing . . . I am very surprised that it was even carried out at this stage. It would certainly not be allowed in Britain.’
John Smeaton, national director of the Society for the Protection of Unborn Children, said: ‘One has tremendous sympathy for couples who suffer infertility problems. But this seems to be a further illustration of the fact that the whole process of in vitro fertilisation as a means of conceiving babies leads to babies being regarded as objects on a production line.
‘It is a further and very worrying step down the wrong road for humanity.’ Professor Cohen and his colleagues diagnosed that the women were infertile because they had defects in tiny structures in their egg cells, called mitochondria.
They took eggs from donors and, using a fine needle, sucked some of the internal material – containing ‘healthy’ mitochondria – and injected it into eggs from the women wanting to conceive.
Because mitochondria contain genes, the babies resulting from the treatment have inherited DNA from both women. These genes can now be passed down the germline along the maternal line.
Jacques Cohen is regarded as a brilliant but controversial scientist who has pushed the boundaries of assisted reproduction technologies.
He developed a technique which allows infertile men to have their own children, by injecting sperm DNA straight into the egg in the lab.
Prior to this, only infertile women were able to conceive using IVF. Last year, Professor Cohen said that his expertise would allow him to clone children –a prospect treated with horror by the mainstream scientific community.
‘It would be an afternoon’s work for one of my students,’ he said, adding that he had been approached by ‘at least three’ individuals wishing to create a cloned child, but had turned down their requests.