Question to the Department of Health and Social Care:

To ask the Secretary of State for Health, with reference to page 15 of Mitochondrial Donation: Government response to the consultation on draft regulations to permit the use of new treatment techniques to prevent the transmission of a serious mitochondrial disease from mother to child, published in July 2014, what the evidential basis is for the statement that donated mitochondrial DNA will not affect personal characteristics.

Physical characteristics and personality traits are inherited from parents’ nuclear DNA. Whole mitochondrial DNA genome sequencing has revealed no evidence of nuclear genomic DNA inside mitochondria and data on the human genome available in the ENSEMBL and OMIM databases confirms that there is no nuclear genomic DNA in the mitochondria. The Revised Cambridge Reference Sequence of the Human Mitochondrial DNA, which can be found at:

http://www.mitomap.org/MITOMAP/HumanMitoSeq

details the whole mitochondrial DNA genome sequence, the codons, the proteins and the genes encoded for. All genes encoded for by mitochondrial DNA are involved in energy production, rather than governing personal characteristics and traits.

Any child born as a result of the use of mitochondrial donation techniques will be genetically unique and will have a natural combination of nuclear genes from both parents but not the mitochondrial donor. As mentioned by the Chief Medical Officer, mitochondrial DNA only encodes genes responsible for energy production and will not affect the child’s appearance, personality or any other personal characteristics.