Question to the Department of Health and Social Care:

To ask the Secretary of State for Health, pursuant to the Written Statement WS132 of 17 December 2014 on mitochondrial donation, whether the expert panel convened by the Human Fertilisation and Embryology Authority regarding mitochondrial transfer found that no females born following spindle-chromosomal complex transfer or pronuclear transfer would ever transmit the disease to subsequent generations.

The principle behind the treatment is that the mitochondrial DNA that the child will inherit will be the disease-free mitochondrial DNA of the donor, not the faulty mitochondrial DNA of their mother. Although there is a small possibility that a low level of unhealthy mitochondria may be carried over when the patient’s nuclear DNA is moved from her egg or embryo to the donor’s, evidence continues to be reassuring that carry-over after mitochondrial replacement is very low and unlikely to be problematic. Therefore, the risks of mitochondrial disease being present in the subsequent generation will be low.