Artificially inseminated babies created from the genes of three people could be a reality as early as 2014, with the UK the first to approve so-called mitochondria replacement to prevent inheritable diseases. The controversial procedure involves transferring the genetic material from two parents into an egg from another woman; by removing the donor egg's nucleus, and replacing it with the parents' nucleus, the risk of inherited defects that could have otherwise been passed down to the baby is removed. However, the fact that the child will have DNA from three parents, not two - albeit only around 0.1-percent from the woman who donated the egg - has some genetic modification opponents angry, given IVF embryos are destroyed in the process.
Mitochondria replacement is promising, because it opens the door to stripping away mitochondrial disorders, which affect around one in 6,500 people, and include heart conditions and muscular dystrophy. The mitochondria are the sources of chemical power in the cells, but if not functioning correctly can leave developing babies short-changed for energy, and as a result health issues.
Where the replacement therapy steps in is in switching out the faulty mitochondria for fully-functioning alternatives. The donor egg's mitochondria has its own genetic material, and so while the bulk of the baby's DNA is that of its parents, from the transplanted nucleus, the all-important "cellular power packs" lack those flaws found in the parents' versions.
For the moment, the procedure is still at the research stage, and has only been shown to work in animals by scientists at Newcastle University in the UK. Nonetheless, the results have been seized upon by the Human Fertilization and Embryology Authority, and the chief medical officer for England, Dame Sally Davies, said on Thursday that "it's only right that we look to introduce this life-saving treatment as soon as we can."
Public attitudes towards mitochondrial replacement have, in the UK at least, been generally positive. Research earlier this year indicated the bulk of people questioned supported it, in fact, and was seen as sufficiently strong for the government to begin working up draft regulations. They're expected to be ready by the fall of 2013.
However, it will require parliamentary approval before it can be deployed to human subjects, and that's not expected to be debated until 2014. Among the concerns are the fact that the baby's DNA is permanently changed by the technique, since it will carry a combination of material from three people, rather than the usual two.
Mitachondria Replacement Therapy overview:
That extra source has some worried that genetic issues around health could arise in later life, and indeed the guidance from Dame Davies is that there would need to be ongoing monitoring of the offspring to ensure that any issues were quickly spotted and, if possible, addressed.
Meanwhile, the same arguments that arose around stem-cell research, still incredibly controversial, have clustered to mitochondrial replacement. The fact that an embryo is in effect dismantled as part of the process has activists unhappy, with complaints that it treats the fertilized egg as "spare parts".
If the UK government approves the regulations, access to mitochondria replacement therapy could be available on the National Health Service (NHS) from as soon as the end of 2014.