The Human Fertilisation and Embryology Authority decided on 15 December 2016 to allow the use mitochondrial donation for risk reduction treatments in certain cases where alternative treatments would be of little or no benefit to mothers at risk of passing mitochondrial disease onto their children. This decision was taken after considering the independent Expert Panel’s fourth report on the latest evidence of safety and efficacy and following a comprehensive and rigorous process of assessment and review of the scientific evidence over the last six years. Before any treatment is offered to affected families, there are still two more licencing processes to be completed. The first to ensure that the clinic meets the required suitability standards and the second a case by case assessment of each individual as required by the Human Fertilisation and Embryology (Mitochondrial Donation) Regulations 2015. NHS England is the designated commissioner of the National Health Service service for mitochondrial donation and will fund the treatment costs of the service, alongside an evaluative research project funded by the Wellcome Trust, which will assess and monitor follow-up and outcomes. Mitochondrial donation does not fit within the definition in law of a clinical trial for the purpose of compliance with the EU Clinical Trial Directive 2001/20/EC. The Directive relates to clinical trials of medicinal products governed by the medicines licensing regime set out in the Medicinal Products Directive and is part of a suite of European measures which set out common rules across the European Union to ensure the free movement of safe medicines. The Government does not agree with the characterisation of mitochondrial donation as a form of genetic modification. The mitochondrial donation techniques do not involve the germ-line modification of nuclear DNA in the chromosomes that can be passed on to future generations, which is the Chief Medical Officer’s working definition of genetic modification in humans. NHS England nationally commissions the rare mitochondrial disease service for adults and children, which provides a comprehensive diagnostic service for patients suffering from mitochondrial disease.