Jessica Hamzelou writes for New Scientist:
A review of technologies that create three-parent embryos to avoid mitochondrial disease has found no evidence that the methods are unsafe, calling for further research. Medical charities have followed up the report with a call to the UK’s health secretary to prepare to regulate the technology in clinics.
A fertilised egg has 98 per cent of its DNA held in its nucleus. Half of this will be from the mother and half from the father. The remaining 2 per cent is what’s known as mitochondrial DNA – DNA in the cells’ “powerhouses” that are found outside of the egg’s nucleus, and are inherited solely from the mother.
Gene mutations in a woman’s mitochondrial DNA can cause mitochondrial disease in her children. The effects can range from mild, almost symptomless disease to serious and often fatal conditions. Researchers are aiming to avoid these serious conditions using donor eggs with mutation-free mitochondria.