Three Biological Parents

A British ethics board recently approved an experimental treatment that results in babies with genetic material from two women and one man. Annalee Newitz explains the need for "three-person IVF":

This procedure is designed to help women who suffer from heritable diseases that are passed on via small pieces of genetic material in the main body of the cell. Most genetic material in your cells is packed into the tiny nucleus at the very center of the cell, but a few pieces of it reside in cell organs called mitochondria that float around in the cell outside the nucleus. The problem is that the child inherits all its mitochondrial DNA from its mother, which means that mitochondrial diseases are hard to shake from one generation to the next. In this procedure, doctors would take healthy donor egg cells, scrape out the genetic material inside the nucleus, and replace it with the mother's DNA. Presto — a baby will be born with the donor mother's mitochondrial DNA, plus nuclear DNA from mom and dad.