Of course, this special process is not applied just for the fun of it. It’s a recent technique, developed by British scientists, which can serve to eliminate specific diseases that are caused by the mitochondria, tiny structures that supply power to cells, which are inherited solely from the maternal side. You might wonder why these diseases can’t be solved with PGD only. I’ll tell you why:
99.8 percent of our DNA is located inside our cells and is inherited evenly from our parents. The remaining 0.2 percent, however, comes from our mitochondria, the parts of the cells that function as the power supplies, and passes directly from our mother to us. Now, disorders in the mitochondria can cause very serious medical conditions, such as muscular dystrophy, heart failures, sight loss and brain damage. About one in 6,500 babies is born carrying some sort of mitochondrial diseases. And because this 0.2 percent comes straight from the maternal side, there is no chance to replace it with DNA from the father. So what can be done for these babies? Just add a third, female parent’s DNA to the mix. For this, a specialized type of IVF is used wherein the genetic material from the mother’s egg is transferred into the donor egg that has its own genetic material removed beforehand. This donor egg containing the mother’s genetic material is then fertilized with the father’s sperm. The baby still receives its physical traits completely from its biological parents, but that 0.2 percent of mitochondrial DNA that would cause so much trouble is provided from the female person who donated the donor egg. The result: a mitochondrial disease-free baby thanks to healthy mitochondrial DNA from an extra parent.
Sounds great? Well, this procedure has not become legal yet because it is considered, once again, extremely controversial and rather experimental. The main reason why this procedure hasn’t been legalized yet is because it is considered germ line gene therapy, since the replaced DNA is passed on from generation to the next. Where is the harm in that if this procedure can eliminate mitochondria related diseases within the family? The problem is that other diseases or defects could be unknowingly passed on as this technique hasn’t been tested for that long. Several people have also expressed moral and ethical concerns, arguing that this technique could truly pave the way for Designer Babies and eugenics (=the prospect of creating a perfect human population by breeding for certain genes). It is also argued that traditional IVF combined with PGD could be used instead to prevent mitochondrial defects by using only a donor egg. This would mean that the baby wouldn’t be biologically related to the mother since there would be only the father’s sperm and the donor’s egg. To put a baby through the unknown risks and consequences of this technique over safe egg donation so that a mother can be biologically related to her child is believed to be even more unethical.
The UK government, however, is set to end the debate and legalize this inheritable human genomes modification. Ministers had decided that the health risks of mitochondrial diseases outweigh all concerns and that regulations will most certainly be drafted by the end of 2014. It is predicted that by early 2015, the UK is going to become the first country worldwide to perform this “three-parent babies” procedure. While many scientists and doctors welcome this new era in genetics, others claim that it will result in more harm than good as the technique is too experimental and hasn't passed enough of the safety texts.
What do you think? Great solution to eradicate severe mitochondrial diseases in the first place, or just another way for scientists to “play god”?
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