The method of creating "children of three parents" is waiting for permission
Two moms for one child
Embryologists fertilized a human female germ cell with mitochondrial DNA previously replaced in it with donor onesGrigory Kolpakov, "Newspaper.
However, at the same time, each rescued child will have two mothers – mitochondrial and nuclear.
The technology is based on the work of a group of embryologists from the USA, from the University of Oregon Health Care, who in the latest issue of the journal Nature announced the successful fertilization of a human female germ cell with mitochondrial DNA previously replaced in it with donor DNA (Tachibana et al., Towards germline gene therapy of inherited mitochondrial diseases).
The mitochondria is a kind of intracellular structure that supplies the cell with fuel – adenosine triphosphate. She got her DNA from some ancient bacterium, and it's very small DNA. Diseases associated with mtDNA defects are quite rare, they affect only one in four thousand children, but most of them are incurable or even fatal.
Oregon embryologists led by Shukhrat Mitalipov, who is known for cloning a monkey for the first time in 2007, tested their mitochondrial transfer technique on macaques three years ago. The essence of the technique is simple: nuclear DNA is removed from an unfertilized egg with defective mitochondria and placed in a healthy donor egg, from which its own DNA has been previously removed. This cell is then fertilized in vitro and placed in the uterus. As a result, as expected, the scientists received healthy macaque offspring with donor mtDNA.
Now, having made sure that the monkey offspring had no long-term side effects, they performed the same operation with a human egg, making only one exception: they brought the ectopic development of embryos to the stage of a blastocyst – a ball containing about a hundred cells.
It didn't work out so well with human eggs – more than half began to develop incorrectly. Mitalipov believes that the reason for this is "incomplete meiosis" (that is, incomplete cell division), and now he is trying to cope with the problem by modifying the technique. The remaining eggs developed normally and had every chance to develop into a full-fledged healthy embryo. In other words, even this technique, with all its imperfections, can at least now be used to fertilize women with mutant mtDNA.
When it comes to manipulating embryos, expect trouble. For Mitalipov, they began immediately. The US National Institutes of Health (NIH) prohibits funding for research in which human embryos are destroyed, even at the blastocyst level. Therefore, Mitalipov was working with money from private sources, and in the laboratory, where the state grants he received for other work did not reach.
Now, when it comes to transferring the technique to clinics, the main ethical question – about the destruction of embryos – is no longer worth it, healthy eggs will be produced there not at all in order to destroy them later, and therefore the NIH may well finance clinical trials of the method.
However, judging by the way things are going, Mitalipov is not at all sure that the NIH will agree to finance them. In the USA, there is an agency called the US Food and Drug Administration (a kind of depersonalized American Gennady Onishchenko), without whose approval no new medical technique can be put into practice. Mitalipov sent a request there back in January, but still has not received any response. And, perhaps, this answer will not come soon. The point here is not the unreliability or other shortcomings of the method, everything seems to be in order with this; lawyers are confused by something completely different – three parents instead of two. The new method of mitochondrial transfer requires the participation of the father, the mother who provided her DNA, and the donor mother who will provide her mitochondria. If desired, considerable legal problems can be identified in this triple alliance, and all subsequent descendants along this line will carry traces of such a union in their genomes.
Mitalipov claims that, having received the official approval, his technique will quickly spread throughout the country. The most complex equipment that will be required for it, according to him, is a microscope and a laser for manipulating an egg, that is, just what is available in any clinic for the treatment of infertility. "The method is simple," he says. "Clinics will learn quickly."
Portal "Eternal youth" http://vechnayamolodost.ru25.10.2012