The breakthrough opens up the possibility of avoiding a range of disorders which can lead to early childhood death. Around one in 6,500 children in the UK is severely affected by the disorders, which can cause muscle weakness, blindness, heart and liver failure, diabetes and learning disabilities. The diseases are all linked to genetic deformities in mitochondria - a component of cells that act like batteries to generate energy Mitochondria DNA is separate from that of the cell nucleus and contains far fewer genes. It is only passed from mothers to their children. There are no treatments available which can...