Question to the Department of Health and Social Care:

To ask Her Majesty’s Government, further to the Written Answer by Earl Howe on 22 January (HL4043), why researchers "believe that being able to undertake the techniques in treatment would provide a greater understanding of the way in which mitochondrial DNA mutations are passed down from mother to child" if they are already confident that the risks of mitochondrial disease in the next generation will be low; which researchers have suggested such investigations, as described in paragraph 1.11 of their February 2014 consultation document entitled "Mitochondrial Donation"; how they propose to investigate how mutations vary in each of the different cells of the resulting children; and what additional information the proposed investigations would be expected to provide that was not previously described in <i>Fertility and Sterility</i> in 2003 (Volume 80, Supplement 3, p56).

Mitochondrial DNA is passed down from mother to child but normal embryonic development can affect how mitochondria are distributed in the different cells and tissues of the body. We are advised that developing mitochondrial donation techniques will help our understanding of this normal phenomenon.

Paragraph 1.11 of the consultation document on the draft mitochondrial donation regulations was informed by researchers who provided evidence to the Human Fertilisation and Embryology Authority convened Expert Panel that conducted three scientific reviews of the safety and efficacy of methods to avoid mitochondrial disease through assisted conception.

We are also advised that the techniques used to investigate how mutations vary in each of the different cells of the resulting children would be identical to those already used to evaluate mitochondrial DNA.

The research abstract in Fertility and Sterility in 2003 (Volume 80, Supplement 3, p56) does not present experimental details.