HONG KONG: A scientist in China claims to have created the world's first genetically-edited babies, in a potentially ground-breaking and controversial medical first.
Chinese university professor He Jiankui posted a video on YouTube saying that the twin girls, born a few weeks ago, had had their DNA altered to prevent them from contracting HIV.
The professor, who was educated at Stanford in the US and works from a lab in the southern Chinese city of Shenzhen, said their DNA was modified using CRISPR, a technique which allows scientists to remove and replace a strand with pinpoint precision.
The development emerged Sunday in an article published by industry journal the MIT Technology Review, which referenced medical documents posted online by He's research team at the Southern University of Science and Technology to recruit couples for the experiments.
He's video then went online, prompting a heated debate among the scientific community, including from experts who cast doubt over the claimed breakthrough, and others who decried it as a modern form of eugenics.
He said the babies, known as "Lulu" and "Nana" although they are not their real names, were born through regular IVF but using an egg which was specially modified before being inserted into the womb.
"Right after sending her husband's sperm into her egg, an embryologist also sent in CRISPR/Cas9 protein and instructions to perform a gene surgery intended to protect the girls from future HIV infection," he said.
The claims come ahead of a conference of world experts in Hong Kong on Tuesday, where He is expected to reveal more details.
But there is as yet no independent verification of his claims, which have not been published in a peer-reviewed journal -- an omission that the scientist's critics have seized on.
"Highly problematic"
The MIT Technology Review warns that "the technology is ethically charged because changes to an embryo would be inherited by future generations and could eventually affect the entire gene pool."
Other scientists have also sounded caution.
Nicholas Evans, assistant professor of philosophy at the University of Massachusetts Lowell, said on Twitter that the claims were "wild".