Question to the Department of Health and Social Care:

To ask the Secretary of State for Health, what his Department's policy is on categorising modification to genomic DNA in mitochondria through pronuclear transfer or maternal spindle transfer as genetic modification.

The Department decided that, because there is no existing universally agreed definition of genetic modification in humans, it would adopt a working definition. The definition that has been adopted is that genetic modification involves the germ-line modification of nuclear DNA (in the chromosomes) that can be passed on to future generations. We will keep this working definition under review.

The proposed mitochondrial donation techniques do not constitute genetic modification.