The news out of the U.K. last year that eight healthy children had been born to mothers carrying disease-causing mutations in their mitochondria showed the promise of a pioneering reproductive technique known as “three-parent IVF.” The long-anticipated results seemingly showed the procedure, formally called mitochondrial replacement techniques, or MRT, could reduce the risk of babies inheriting sometimes fatal diseases, and raised hopes that other countries, such as the U.S. where MRT is banned, might soon permit it.
But even as regulators and researchers in Australia, the second country to explicitly legalize the specialized technique, prepare to launch their own national experiment with MRT, some scientists and ethicists are rethinking the potential risks and benefits of the technology, which combines genes from a mother and father with mutation-free DNA in the mitochondria of a donor egg. Emerging data from the U.K. as well as several small pilot studies from fertility clinics in other parts of the world are raising questions about whether trying to prevent mitochondrial disease is really the best first use of MRT.
