The Conservative MP for North East Somerset, Jacob Rees-Mogg, has said that mitochondrial donation will produce 'genetically modified children' with 'three parents', and was 'effectively cloning'. He also described mitochondrial donation as a 'multi-generational experiment' that 'tampered with human souls'.
Rees-Mogg made the comments in a Parliamentary debate on Wednesday, during which some MPs expressed concern over the safety and ethics of using mitochondrial donation to enable women with defective mitochondria to have healthy children.
In her response, the Parliamentary Under-Secretary of State for Health, Jane Ellison, asserted that mitochondrial donation'did not constitute a form of human cloning' since 'any children resulting from the use of the technique would have arisen from fertilisation and be genetically unique'. This contrasts with cloning, where the offspring produced are genetically identical to the 'parent'.
Ellison also referenced an ethical review of mitochondrial donation by the Nuffield Council on Bioethics, which rejected the idea that mitochondrial donation represented a 'third parent' (reported in BioNews 661). This is in agreement with the findings of a public consultation on mitochondrial donation by the Human Fertilisation and Embryology Authority, which considered that mitochondrial donors are best thought of as similar to organ or tissue donors.
Mitochondrial DNA constitutes less than one percent of a person's genome, and is separate from nuclear DNA. Mitochondrial replacement involves removing the nuclear genetic material from an egg or embryo with unhealthy mitochondria and transferring it to a donor egg or embryo with healthy mitochondria. The technique, Ellison explained, gives 'women the choice to have genetically related children without the risk of serious disease', which could initially help ten to 20 families a year.
In her statement, Ellison highlighted the nature and impact of mitochondrial diseases. 'Some affected children live short and painful lives', she said; adding that 'the quality of life for them and their families is seriously diminished'. Clinical features of mitochondrial disease include muscle weakness, learning difficulties, heart disease and blindness, with one in 6,500 babies so severely affected they die in early infancy.
In additional to ethical reservations, Rees-Mogg also raised concerns over safety, citing a study in Nature that reported chromosomal abnormalities in 52 percent of embryos created following one method of mitochondrial transfer. This interpretation contrasted with that of the study's lead researcher, Dr Shoukhrat Mitalipov, who stated that the process was, in his view, 'safe enough at this stage to proceed to clinical trials [in humans]' (reported in BioNews 679).
Ellison confirmed that a full Parliamentary debate on the issue would take place.She also revealed she was 'sure' that a Parliamentary ruling on mitochondrial donation would be 'decided by votes of conscience'.