Core transfer against infertility

The creator of the first "child from three parents" launched a medical startup

Ekaterina Rusakova, N+1

Last year, for the first time in the world, a "child from three parents" was born in Mexico. It was born as a result of the transfer of the nucleus from one egg to another containing healthy mitochondrial DNA. The procedure was performed by researchers under the guidance of endocrinologist John Zhang. Later, Tsang founded a startup Darwin Life, which offers to cure infertility of women over 40 years of age with the help of the core transfer procedure. The new startup is reported by MIT Technology Review (The Fertility Doctor Trying to Commercialize Three-Parent Babies).

Mitochondria are organelles that provide eukaryotic cells with energy. They have their own small DNA molecule (there are only 16569 base pairs in human mitochondrial DNA), which in most organisms is inherited through the maternal line. Mutations often occur in mitochondrial DNA, which, unlike DNA in chromosomes, are not corrected by sexual recombination. As a result, there is a significant number of hereditary diseases. Their transmission can be excluded if the mitochondria in the maternal egg are replaced with mitochondria from the egg of a healthy female donor, or the maternal nuclear DNA is transferred from an egg with "sick" mitochondria to a donor egg with a removed nucleus and healthy mitochondria.

Initially, the procedure for transferring the nucleus from one unfertilized egg to another (maternal spindle transfer) was developed in order to replace the mitochondria of the mother, whose DNA has harmful mutations, with healthy mitochondria of the donor woman. With the help of this procedure, doctors led by John Tsang helped a woman carrying Ley syndrome (a hereditary neurological disease) to give birth to a healthy "child from three parents" for the first time. In addition to the paternal and maternal nuclear DNA, the child has the mitochondrial DNA of a female donor.

Now Tsang suggests using the maternal spindle transfer technology for women over 40 years old who have not been able to get pregnant for a long time. As it is written on the Darwin Life website, "the transfer of the nucleus not only reduces the risk of becoming a carrier of genetic diseases transmitted through the maternal line, but due to the transfer to the egg of a younger donor woman, it increases the chances of a successful pregnancy." The creators of the startup do not provide experimental data that would allow evaluating the effectiveness of such a procedure. According to Tsang, 8,700 in vitro fertilization operations were performed in the United States in 2014 and less than four percent of them ended successfully.

Since the use of technology is prohibited in the United States, Tsang plans to create embryos in his clinic in New York, but to carry out all medical procedures already in Mexico or in other countries where there are no strict prohibitions. Artificial insemination with the new technology will cost from 80 to 120 thousand dollars.

At the beginning of 2017, Ukrainian doctors reported the birth of a second "child from three parents." Unlike Tsang's team, for the first time in history, Ukrainian reproductologists used a different method – pronuclear transfer - when transferring a nucleus to a donor egg.

Doctors first fertilized both eggs with paternal sperm, both maternal and donor, and then transferred the nucleus from the mother to the donor cell.

Portal "Eternal youth" http://vechnayamolodost.ru  15.06.2017