Today, MPs will vote on whether to allow a technique known as mitochondrial transfer. Critics have unhelpfully taken to calling it the ‘three-parent baby’ technique, since defective mitochondrial DNA from a mother’s egg is replaced with healthy mitochondria from a donor. Less than 0.001 per cent of the resulting child’s DNA is replaced in the process and it does not affect characteristics such as physical attributes, intelligence or personality.
Mitochondria are structures that create the energy to run a cell and have their own genome. Harmful mutations in mitochondrial DNA can result in a number of serious, potentially life-threatening diseases such as cardiac impairment, muscle-wasting conditions and diabetes. Children inherit defective mitochondrial DNA from their mothers and can be carriers of the condition without experiencing ill-effects themselves. Mitochondrial transfer prevents these harmful mutations being passed on to future generations.
Critics maintain that mitochondria structures may have more of an impact on personal traits than has been envisaged. Some find it unethical that the technique involves the destruction of an egg (the nucleus is removed from both eggs, the donor nucleus is destroyed and the mother’s nucleus is inserted into the donor egg). Others are concerned that it might lead to a market in ‘designer’ babies.
Should the technique be allowed?