Chinese scientists from the Sun Yat-sen University in Guangzhou have confirmed to the world that they are the first to genetically engineer human embryos. They say that they modified the responsible gene that leads to thalassemia, a fatal blood disorder.
Fears of designer babies
Knowing the medical community at large would raise alarms of eugenics, the research team leader Junjiu Huang assured that all the embryos used were “non-viable” and would never become living babies.
Critics are not reassured however, and have called for a worldwide ban on the practice of genetic engineering as they fear it is a first step towards designer children. Europe already has a ban in place on the practice of DNA editing in human embryos.
The science journals Nature and Science refused to publish the research study on ethical grounds, yet it was eventually published in the journal Protein and Cell.
Many scientists agree it should be banned
“This news emphasizes the need for an immediate global ban on the creation of GM designer babies,” stated Human Genetics Alert Director, Dr. David King. “It is critical that we avoid a eugenic future in which the rich can buy themselves a baby with built-in genetic advantages.”
On the recent research aimed at thalassemia, King said, “It is entirely unnecessary since there are already many ethical ways to avoid thalassemia. This research is a classic example of scientific careerism – assuring one’s place in the history books even though the research is unnecessary and unethical.”
CRISPR/Cas9 technique
The genetic engineering technique employed by the Chinese team is known as CRISPR/Cas9, which was originally discovered by MIT scientists.
CRISPR works by duplicating the way a virus is attacked by bacteria that snip away at its genetic code. Likewise, the CRISPR method uses a protein derived from bacteria to snip away a specific gene. The missing gene is replaced by a different molecule simultaneously. Previously, the technique has only been used on animal models and adult cells, never in the cells of human embryos.
An ethical line in the sand
While some advocate that genetic engineering might be valuable in eliminating devastating diseases, others fear that it would be misused. It could easily cross the ethical line into genetic engineering of designer children.
Because genetic changes would happen to living embryos, those changes would also be passed down to following generations and have long lasting effects. There are many ways in which this research could lead to devastating results scientists are not fully aware of yet.
Unexpected results including mutations
The Chinese team used 86 embryos from fertility clinics that had an extra set of chromosomes and had been fertilized by two sperm. This is what prevents them from ever ending up as a live birth.
The embryos were injected with the Cas9 protein and then remained untouched for two days during the process of the gene-editing. Afterward, 71 embryos survived, and genetic testing was done on 54 of them. Of those tested, 28 embryos had been successfully spliced; however, only a small portion of those were shown to contain the genetic material replacement.
As further proof of the unpredictable nature of genetic engineering, a number of surprising mutations were found in genes that were not expected to be affected by the CRISPR technique.
Outspoken opposition
Meanwhile, the medical community at large is voicing its concerns over this controversial research.
“I think that this is a significant departure from currently accepted research practice. Can we be certain that the embryos that the researchers were working on were indeed non-viable?” asked Shirley Hodgson, professor of cancer genetics at St. George’s, University of London. “Any proposal to do germline genetic manipulation should be very carefully considered by international regulatory bodies before it should be considered as a serious research prospect.”
“This story underlines the urgent necessity for international dialogue over the ethics of germline editing in human embryos, well in advance of any progression towards theoretical, clinical application,” stated Dr. Philippa Brice, of the health policy think-tank the PHG Foundation. “Recent calls for a moratorium on any such research to allow time for expert and public consideration of what is and is not ethically, socially and indeed legally acceptable with respect to human germline genetic modification should definitely be heeded.”
“The study is a landmark, as well as a cautionary tale,” said stem-cell biologist George Daley, with the Harvard Medical School in Boston. “Their study should be a stern warning to any practitioner who thinks the technology is ready for testing to eradicate disease genes.”
Continuing despite opposition
Huang claims he has abandoned the controversial research and returned to the study of surprising mutations in animals and adult cells. At this time, it is believed that four other groups of researchers in China are working on human embryo genetic modification.
—Alternative Daily
Sources:
http://time.com/3832908/crispr-embryos
http://www.nbcnews.com/health/health-news/chinese-gene-editing-experiment-creeps-out-scientists-n346916
http://www.telegraph.co.uk/news/science/11558305/China-shocks-world-by-genetically-engineering-human-embryos.html
