What we know about gene-editing experiments in Britain

Britain has given a group of scientists the OK to conduct gene-editing experiments on human embryos. Here’s what we know:

— Scientists say deleting, repairing or replacing faulty DNA at the embryonic stage could someday be used to treat or prevent certain diseases.

— Some ethicists warn that such experiments are a step toward “designer babies,” created by their parents to be smarter, stronger or better-looking. Some critics also warn that tinkering could have unfortunate consequences generations from now.

— The scientists who won approval say they will not try to create babies — the modified embryos will be destroyed after seven days. The goal, they say, is to understand human embryonic development better so as to improve fertility treatments.

— This marks the first time that a country’s national regulator has approved such research. The U.S. has no ban on gene-editing of embryos but does not allow the use of federal funds for such work.