Three-parent baby technique could create babies at risk of severe disease

When the first baby born using a controversial procedure that meant he had three genetic parents was born back in 2016, it made headlines. The baby boy inherited most of his DNA from his mother and father, but he also had a tiny amount from a third person.

The idea was to avoid having the baby inherit a fatal illness. His mother carried genes for a disease in her mitochondria. Swapping these with genes from a donor—a third genetic parent—could prevent the baby from developing it. The strategy seemed to work. Now clinics in other countries, including the UK, Greece, and Ukraine, are offering the same treatment. It was made legal in Australia last year.