In a world first, Chinese scientists have successfully edited human DNA in an embryo by using a cutting edge technology, causing uproar among some in the scientific community.
Huang Junjiu, associate professor of biology at Sun Yat-sen University in Guangzhou, and colleagues used the technology to "cleave" a gene responsible for beta thalassemia.
Researchers used problematic embryos discarded by hospitals, or eggs each fertilised by multiple sperms, which had been used by scientists around the world in lab for decades because they would never lead to a live birth.
Writing in the journal Protein and Cell, researchers said they were aware of the ethical controversy surrounding such studies, 'South China Morning Post' reported.
"We need to pause this research and make sure we have a broad based discussion about which direction we are going here," British biologist Edward Lanphier told Nature.
However, Chen Guoqiang, professor of biology with Tsinghua University, said the critics' demand was arbitrary.
"The breakthroughs in this field of research will eventually benefit every one of us. The editing of human DNA holds the key to cure many diseases, maintain health, retain youth, live long. These will all be possible in the future and free many families from pain and sufferings," said Chen.
Zhao Shimin, biologist with Fudan University in Shanghai, said the study by Huang's team had "absolutely no ethical problem."
"They are only experimenting with non-viable embryos. The research is far, far away from clinical application or commercial use," he said.
Huang's team experimented with 86 discarded embryos and found that the editing was only successful in 28, or around 30 per cent of embryos.
The new editing technology, known as CRISPR, frequently missed the targeted gene, and some mutations were detected in the embryos following treatment.
The results "present obvious obstacles to gene therapy strategies" while many issues "should be investigated thoroughly before any clinical application," the team wrote.
