Researchers report that eight healthy babies were born with the help of an experimental technique that uses DNA from three people to help mothers avoid passing rare diseases to their children. Dangerous mutations in the cell’s mitochondria can cause a range of diseases, some causing major organ failure and death.  Researchers have been developing a technique that takes genetic material from the mother’s egg or embryo, which is then transferred into a donor egg or embryo that has healthy mitochondria but the rest of its key DNA removed. Scientists described their findings in the New England Journal of Medicine on Wednesday.