Published in the journal Nature, the scientists reported an in-depth analysis of human embryos created using the new technique designed to reduce the risk of mothers passing on mitochondrial disease to their children, which is debilitating and often life-limiting.
Mitochondrial disease is a chronic, genetic disorder that occurs when the mitochondria of the cell fail to produce enough energy for cell or organ function, according to MitoAction, a US-based organisation working to improve quality of life for adults and children affected by the disease.
The new technique, called “early pronuclear transfer,” involves transplanting the nuclear DNA from a fertilised egg into a donated egg, which contains healthy mitochondria, on the day of fertilisation.
Results of the study involving over 500 eggs from 64 donor women indicate that the new procedure does not adversely affect human development and will greatly reduce the level of faulty mitochondria in the embryo.
The results suggest that the technique will lead to normal pregnancies whilst also reducing the risk of babies having mitochondrial disease. “This study using normal human eggs is a major advance in our work towards preventing transmission of mitochondrial DNA disease,” said co-author of the paper, Professor Doug Turnbull, Director, Wellcome Trust Centre for Mitochondrial Research in Britain. “The key message is that we have found no evidence of the technique being unsafe. Embryos created by this technique have all the characteristics to lead to a pregnancy,” Turnbull noted.
Once licensed, the new technique would allow couples affected by mitochondrial disease to have the choice of whether to use pronuclear transfer to try and have healthy children.
“Having overcome significant technical and biological challenges, we are optimistic that the technique we have developed will offer affected women the possibility of reducing the risk of transmitting mitochondrial DNA disease to their children,” said senior author of the study Mary Herbert from Newcastle University in England.