The UK Government is to support the introduction of mitochondrial replacement therapy. The IVF-based procedure could allow women with mitochondrial disease the opportunity to have healthy children, by replacing their own, faulty mitochondria with healthy mitochondria from a donor.
There are currently two mitochondrial replacement techniques in development, both of which involve transferring the nuclear DNA of the future parents into a donor egg containing healthy mitochondria. 'Pronuclear transfer' involves taking the nucleus of a fertilised egg containing DNA from both the father and mother, and transferring it into a donor egg in which the nucleus has been removed. In the alternative method, 'maternal spindle transfer', the mother's DNA is transferred to the donor egg before it is fertilised. The treatments have been shown to be effective in animals but could not be fully tested in humans without changes made by Parliament.