On Sept. 6, 2022, scientists in China announced that they had conducted the first comprehensive study of the technique in early-stage human embryos, and reported that it does not seem to affect their development.

About one in 5,000 children are born with diseases caused by harmful mutations in their mitochondrial DNA. The faulty genes can lead to problems in many organs including the heart and the brain.

By creating a safety study on spindle transfer, the results will provide important evidence to help regulators in countries where the process is not allowed assess its safety and efficacy, which in turn could advance the field. The study was published in Nature.