Q&A On Scientist's Bombshell Claim Of Gene- Edited Babies

Designer babies might be here sooner than anyone reckoned. A Chinese researcher who says he created gene-edited babies crossed what most scientists consider a forbidden line.

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It’s not clear if the claim is true and if so, how the twin girls whose DNA reportedly was altered will fare as they grow.

There is wide scientific agreement that rewriting DNA before birth — to prevent an inherited disease or to give a baby some “designer” trait — isn’t yet safe to try outside laboratory experiments that do not lead to human births.

“Grossly premature and deeply unethical,” is how noted U.S. bioethicist Henry Greely of Stanford University characterized the claim.

The researcher, He Jiankui of Shenzhen, said he altered embryos when parents were undergoing fertility treatments to change a gene so that it might provide the resulting babies with a trait few people naturally have — protection against future infection with the AIDS virus.

“This is probably the worst gene you would choose” to test in pregnancy because it doesn’t fix a disease the children were destined to get, said Shoukhrat Mitalipov of the Oregon Health & Science University, who in laboratory-only experiments studies how to repair gene defects in embryos.

“Where is the assurance this mutation now will result in resistance to HIV?” Mitalipov added. “He’s testing his hypothesis on babies.”

Here are questions and answers about Monday’s claim and the state of gene editing:

WHAT IS GENE EDITING?

It’s a technology that lets scientists alter the DNA of living cells — from plants, animals, even humans — more precisely than ever before. It’s like a biological cut-and-paste program: An enzyme that acts like molecular scissors snips a section of a gene, allowing scientists to delete, repair or replace it.