Question
To ask Her Majesty’s Government, further to the Written Answer by Earl Howe on 16 December 2010 (WA 210–11) about the report by the Medical Research Council (MRC) and the California Institute for Regenerative Medicine, whether the MRC or members of the Human Fertilisation and Embryology Authority and its Horizon Scanning Panel are aware of any clear and quantitative means for identifying those oocytes with the potential to develop disease without destroying any oocytes in the process of determining the level of heteroplasmy for mitochondrial mutations.
Answer
The Medical Research Council has advised that, at present, there is no clear and quantitative means for identifying those oocytes with the potential to develop disease without destroying the oocytes. Researchers are exploring the possibility of testing the polar bodies. This method would, however, be limited in its reliability as mitochondria do not segregate equally between oocytes and the polar body and there would be quite a high risk that the polar body was not representative of the whole oocyte. In addition, polar bodies are very small and degenerate very easily so this would be a very difficult technique to develop. While it is conceivable that a test could be developed for heteroplasmicity, this technique would not help women who were homoplasmic. The Human Fertilisation and Embryology Authority (HFEA) has advised that its Scientific and Clinical Advances Advisory Committee keeps under review scientific developments relevant to assisted conception and human embryo research. The Committee considered techniques for the avoidance of mitochondrial disease at its meeting of 13 May 2010. The relevant papers and minutes of that meeting are available on the HFEA's website.