Human Fertilisation and Embryology

This is a difficult issue for everybody. I have a real difficulty with this, which is that I cannot see the difference between modifying mitochondrial DNA and nuclear DNA. Both are inherited, and both can prevent inherited diseases. If we agree to this as a process, we are, in essence, potentially agreeing to swapping a pair of chromosomes—[Interruption.] I know that we are not agreeing to it in law, but in practice the same arguments can be used to justify—