Apparently we could soon have three-person IVF. At first I thought this had something to do with the three-person civil union which has been recognised in Brazil. But no, this is an entirely differnt kettle of ethical fish (dophin-friendly tuna, perhaps?). Genetic manipulation could result in babies with DNA from 3 different adults. Leaving aside the issue of IVF itself, the suppoosed medical benefits would theoretically be the elimination of genetic mitochondrial disorders.
The Nuffield Council on Bioethics highlight a number of ethical concerns but have given this proceduce the ethical OK - so long as it is medically safe - but Human Genetics Alert (a secular, independent public interest watchdog group) is concerned about the procedure leading to demand for genetic designer babies. They argue in favour of abortion on the basis that "the foetus is part of the mother's body" (a topic for another time methinks) but are against sex-selection because it smacks of discrimination and eugenics.
Frankly, I think they are right to be concerned. Despite being illegal, it has been demonstrated the sex-selective abortions are taking place for purposes of "family balancing" throughout the UK, (ie 'I can only afford to have two children and I've already got a girl so I need a boy this time'). Talking about the slippery slope may be a cliche but it should be obvious by now that if it is possible to abuse a technique in some way, then people will find a way of doing it whether within or without the law. With sex-selective abortion we have seen a step towards designer babies; with the ability to add the DNA of a third person into the mix, how long will it be before parents decide that they need their child to be taller, thinner, smarter, faster or better looking than all the others in their classroom.