In a two-day-long public hearing, the advisory committee, led by Dr Evan Snyder of Sanford-Burnham Medical Research Institute in La Jolla, California, heard medical evidence from scientists on the technique's safety in humans. Issues discussed included risks posed to the mother and child, results of similar studies in animals, and further research required.
Supporters argued that the technique, if allowed, could be used to prevent mitochondrial diseases. Some critics, however, said this would lead to 'designer babies'. Regardless, scientists were asked to advise only on the scientific implications of the technique, not its legal or ethical implications.
The hearing was prompted when Dr Shoukhrat Mitalipov, researcher from the Oregon Health and Science University in Portland, USA, sought the FDA's approval to begin testing the technique on women with mitochondrial disease. Dr Mitalipov told the committee that his research team had successfully performed the technique on monkeys, and that it is now ready to be tried on humans.
Mitochondrial replacement involves replacing an egg's faulty mitochondria with healthy mitochondria from a donor's egg, either before or after fertilisation. The egg will retain DNA from the nucleus of the mother-to-be and the healthy mitochondrial DNA from the donor. The resulting child will not inherit the genetic disease, but will inherit traits like eye colour and height from the parents.
More than 4,000 children are born with inherited mitochondrial diseases every year. Mitochondrial diseases can be impossible to diagnose prenatally and are incurable. If successful, mitochondrial replacement could potentially prevent such diseases from being passed down to a child.
Dr Snyder noted that some committee members expressed concern over the safety of the trial on humans.
'There was probably not enough data in animals… to move on to human trials without answering a few additional questions [about safety]', he said at the end of the hearing.
Jennifer Rodriguez, an FDA press officer, told Reuters: 'We have heard the concerns expressed at the advisory committee meeting, and will take the information back to consider whether we need to facilitate a public discussion and, if so, how best to do this'.