Chinese scientist says twin baby girls were genetically edited

A Chinese researcher claims he helped make the world’s first genetically edited babies – twin girls whose DNA he said he altered with a powerful new tool capable of rewriting the very blueprint of life.

There is no independent confirmation of the claim, and the research has not been published in a journal, where it would be vetted by other experts.

A US scientist said he took part in the work in China, but this kind of gene editing is banned in the United States because the DNA changes can pass to future generations and it risks harming other genes.

Many mainstream scientists think it is too unsafe to try, and some denounced the report as human experimentation.

The researcher, He Jiankui of Shenzhen, said he altered embryos for seven couples during fertility treatments, with one pregnancy resulting thus far.

He said his goal was not to cure or prevent an inherited disease, but to try to bestow a trait that few people naturally have – an ability to resist possible future infection with HIV, the virus which leads to Aids.

He said the parents involved declined to be identified or interviewed, and he would not say where they live or where the work was done.

Mr He revealed the news yesterday in Hong Kong to one of the organisers of an international conference on gene editing that is set to begin today.

“I feel a strong responsibility that it’s not just to make a first, but also make it an example,” Mr He said.

“Society will decide what to do next” in terms of allowing or forbidding such science, he added.

Some scientists were astounded to hear of the claim and strongly condemned it.

Dr Kiran Musunuru, a University of Pennsylvania gene editing expert and editor of a genetics journal, said it was “unconscionable … an experiment on human beings that is not morally or ethically defensible”.

“This is far too premature,” said Dr Eric Topol, who heads the Scripps Research Translational Institute in California. “We’re dealing with the operating instructions of a human being. It’s a big deal.”

However, one famed geneticist, Harvard University’s George Church, defended attempting gene editing for HIV, which he called “a major and growing public health threat”.

In recent years, scientists have discovered a relatively easy way to edit genes, the strands of DNA that govern the body.

The tool, called CRISPRCAS9, makes it possible to operate on DNA to supply a needed gene or disable one that is causing problems.

It has only recently been tried in adults to treat deadly diseases, and the changes are confined to that person.