[ad_1]
Breaking News Emails
Receive last minute alerts and special reports. News and stories that matter, delivered the mornings of the week.
/ Source: Associated press
By Marilynn Marchione, Associated Press
HONG KONG – A Chinese researcher claims to have helped create the world's first genetically modified baby – twin babies born this month, whose DNA he modified with a powerful new tool that can rewrite the model of life.
If this is true, it would be a giant leap forward in science and ethics.
An American scientist said that he had taken part in the work in China, but this type of genetic modification is banned in the United States because DNA changes can be passed on to future generations and could harm other genes.
Many mainstream scientists think it is too dangerous to try, and some have called the Chinese report human experimentation.
The researcher, He Jiankui of Shenzhen, said he has modified embryos for seven couples during fertility treatments, with a pregnancy up to now. He stated that his goal was not to cure or prevent an inherited disease, but to try to confer a trait that few people naturally have: the ability to withstand a possible future HIV infection , the AIDS virus.
He added that the parents concerned did not want to be identified or interviewed and that he would not tell them where they lived or where the work was done.
There is no independent confirmation of his request, and it has not been published in a journal where it would be verified by other experts. He revealed it Monday in Hong Kong at one of the organizers of an international conference on gene editing that should open Tuesday, and earlier in exclusive interviews with The Associated Press.
"I feel a strong responsibility that it's not enough to make a first, but also to make an example," he told the AP. "Society will decide what to do next" to allow or prohibit such science.
Some scientists were stunned to learn this statement and strongly condemned it.
This is "unacceptable … an experiment on human beings that is morally and ethically untenable," said Dr. Kiran Musunuru, Gene Publishing Expert at the University of Pennsylvania and editor-in-chief of the University of Pennsylvania. a journal of genetics.
"It's way too early," said Eric Topol, director of the Scripps Research Translational Institute in California. "We are talking about a user's manual. It's a big problem. "
However, a prominent geneticist, George Church of Harvard University, defended any attempt to modify the gene for HIV, which he described as "a major and growing threat to public health."
"I think it's justifiable," said Church about this goal.
In recent years, scientists have discovered a relatively easy way to edit genes, the DNA strands that govern the body. This tool, called CRISPR-cas9, allows you to operate on the DNA to provide the necessary gene or to disable one that causes problems.
It is only recently that attempts have been made to treat life-threatening diseases in adults, and the changes are limited to that person. The edition of spermatozoa, oocytes or embryos is different – the changes can be inherited. In the United States, it is not allowed except for laboratory research. China prohibits human cloning, but not specifically gene editing.
He Jiankui, who goes through "JK", studied at the American Rice and Stanford Universities before returning to his home country to open a laboratory at the China University of Science and Technology in Shenzhen, where he owns also two genetics companies.
The American scientist who worked with him on this project after returning to China was Michael Deem, professor of physics and bioengineering, who was his adviser at Rice in Houston. Deem also holds what he called "a small stake" and is part of the scientific advisory boards of his two companies.
The Chinese researcher said that he was practicing the editing of mice, monkey embryos and human embryos in the laboratory for several years and had filed patent applications for his methods.
He said he chose the edition of embryo genes for HIV because these infections are a serious problem in China. He sought to disable a gene called CCR5 that forms a protein gateway allowing HIV, the virus at the origin of AIDS, to enter a cell.
All the men involved in the project were HIV-positive and not all women, but the gene editing was not intended to prevent the low risk of transmission, he said. Conventional HIV medications have profoundly inhibited fathers' infections and there are simple ways to prevent them from infecting offspring without altering genes.
Instead, the call was to offer couples affected by HIV a chance to have a child who could be protected from a similar fate.
He recruited couples through an AIDS advocacy group, Baihualin, based in Beijing. Its leader, known as "Bai Hua," told the AP that it is not uncommon for HIV-positive people to lose their jobs or find it difficult to get medical attention if their infection is revealed.
Here's how he described the work:
Gene editing occurred during IVF or laboratory fertilization. First, sperm has been "washed" to separate it from sperm, the fluid where HIV can hide. A single sperm was placed in a single egg to create an embryo. Then, the gene editing tool was added.
When the embryos were 3 to 5 days old, some cells were picked and checked for editing. Couples can choose to use published or unedited embryos for their pregnancy attempts. In total, 16 of the 22 embryos were published and 11 embryos were used in six implant attempts prior to twin pregnancy, he said.
The tests suggest that one of the twins has modified both copies of the desired gene and that the other twin has only one, with no evidence of damage to others. genes, he said. Individuals with a copy of the gene can still contract HIV, although very limited research suggests that their health may degrade more slowly once it has occurred.
Several scientists reviewed the documents he had provided to the PA and stated that the tests carried out so far were insufficient to say that editing had worked or to rule out any risk of harm.
They also found evidence that the check was incomplete and that at least one of the twins appeared to be a patchwork of cells with various changes.
"It's almost like not publishing at all" if only some of some cells were changed, because HIV infection could still occur, Church said.
Church and Musunuru have questioned the decision to allow the use of one of the embryos during an attempted pregnancy because Chinese researchers have stated that they knew of That both copies of the desired gene had not been altered.
"In this child, there was virtually nothing to gain in terms of protection against HIV and yet you expose this child to all unknown security risks," said Musunuru.
The use of this embryo suggests that the researchers "have focused primarily on assembly testing rather than on avoiding this disease," Church said.
Even if the editing worked perfectly, people without normal CCR5 genes are at a higher risk of contracting some other viruses, such as West Nile, and dying of the flu. As there are many ways to prevent HIV infection and it is very easy to treat if it occurs, these other medical risks are a concern, said Musunuru.
There are also questions about how he said that he proceeded. He officially announced his work long after declaring it started – on Nov. 8, on a Chinese clinical trial registry.
It is unclear whether the participants understood the purpose, as well as the risks and potential benefits. For example, the consent forms called the project an "AIDS Vaccine Development" program.
The scientist Rice, Deem, said that he was present in China when potential participants gave their consent and that he thought "absolutely" that they were able to understand the risks.
Deem said that he had worked with He on finding a vaccine at Rice and that gene editing was similar to a vaccine.
"It may be a simple way to describe the layman," he said.
Both men are experts in physics with no experience in conducting human clinical trials.
The Chinese scientist, He, said that he had personally stated his goals and told participants that embryo gene editing had never been tried before and that it was entailed risks. He added that he would also provide insurance coverage to all children conceived under the project and plan a medical follow up until the children are 18 years old and older. they agree to become adults.
Other pregnancy attempts are pending until the safety of the pregnancy is analyzed and experts from the field intervene, but the participants were not notified in advance. that they might not have the opportunity to try what they had signed for the first time. , He acknowledged. Free fertility treatment was part of the offer.
He sought and obtained approval for his project from Shenzhen Harmonicare Hospital for Women and Children, which is not one of four hospitals that he said provided embryos for his research. or her pregnancy attempts.
Some staff from other hospitals were kept informed of the nature of the research. According to him, Deem and himself were made to prevent disclosure of HIV infection by some participants.
"We think it is ethical," said Lin Zhitong, a director of Harmonicare who heads the ethics committee.
All the medical staff who handled samples that might contain HIV knew about it, he said. Qin Jinzhou, an embryologist from He's lab, confirmed to the PA that he had washed the semen and injected the genetic modification tool during some pregnancy attempts.
The study participants are not ethicists, he said, but "are so much authority over what is right and wrong, because it is their life at stake".
"I think it will help families and their children," he said. If this causes unwanted side effects or damage, "I would feel the same pain as them and that would be my own responsibility".
Source link
