As chief executive of the UK Human Fertilisation and Embryology Authority (HFEA), I take issue with Marcy Darnovsky's criticisms of our public consultation on mitochondria replacement in reproductive therapy (Nature 499, 127; 2013).

Darnovsky queries the statistic used by the HFEA: “one in 200 children is born each year with a form of mitochondrial disease.” This comes from a study of mitochondrial mutations in the general population (H. R. Elliot et al. Am. J. Hum. Genet. 83, 254–260; 2008) and includes children with mild or no symptoms. Other UK organizations use the same figure, notably the National Health Service (see go.nature.com/dcocm2) and the Nuffield Council on Bioethics (see go.nature.com/s6z8gk).

Darnovsky also questions parts of the HFEA's methodology and conclusions. The consultation was designed with external experts, and enabled public participation in various 'strands' that used qualitative and quantitative analysis. Our aim was to go beyond 'yes' or 'no' responses. In all but one of five strands, most people supported mitochondria-replacement techniques. Our publicly open questionnaire drew more opposition from its self-selected respondents, with some arguing that any in vitro manipulation of embryos is inappropriate or unethical.

All the consultation material is available at our website (www.hfea.gov.uk/7784.html). I suggest that people judge for themselves.