Experts weigh medical advances in gene-editing with ethical dilemmas

Hundreds of scientists, doctors, bioethicists, patients, and others started gathering in London Monday for the Third International Summit on Human Genome Editing. The summit this week will debate and possibly issue recommendations about the thorny issues raised by powerful new gene-editing technologies.

The last time the world's scientists gathered to debate the pros and cons of gene-editing — in Hong Kong in late 2018 — He Jiankui, a biophysicist and researcher at Southern University of Science and Technology in Shenzhen, China, shocked his audience with a bombshell announcement. He had created the first gene-edited babies, he told the crowd — twin girls born from embryos he had modified using the gene-editing technique CRISPR.

He, who had trained at Rice University and Stanford, said he did it in hopes of protecting the girls from getting infected with the virus that causes AIDS. (The girls' father was HIV-positive.) But his announcement was immediately condemned as irresponsible human experimentation. Far too little research had been done, critics said, to know if altering the genetics of embryos in this...