The scientist's colleagues from China criticized the experimenter's actions and demand an investigation of his activities.
Late last year, Chinese scientist He Jiankui, a professor at the Southern University of Science and Technology in Shenzhen, announced the birth of the first genetically modified twins. According to the scientist, as a result of the experiment, Nana and Lulu, twins born from an HIV-infected father, became immune to infection. After the results of the experiment were announced, scientists, politicians and philosophers around the world attacked Jiankui with criticism, accusing him of violating laws and moral standards. Shortly thereafter, the scientist mysteriously disappeared, and information appeared in the media about his placement under house arrest. According to some reports, he could face the death penalty.
Leading scientists in the field of DNA modification, the Chinese Haoi Wang and Hui Yang, decomposed the inconsistencies of the controversial experiment in the journal Plos Biology.
Experts believe that there was no need to edit the genes of the embryos in order to prevent HIV transmission from an infected parent. Currently, assisted reproductive technologies can protect the embryo from transmitting the virus to an infected parent.
He Jiankui edited the CCR5 gene, with the participation of which HIV is transmitted. But the fact is that the mutant version of this gene, which the scientist introduced into the twins' DNA, is found only in the European population. According to scientists, the presence of this mutant gene in the gene pool of the Chinese can lead to unpredictable consequences.
Hye Jiankui's experiments on editing the CCR5 gene in mice have also been questioned. As a result of these experiments, it was planned to understand whether editing would lead to any undesirable changes in the physiological functions or behavior of the mice. According to experts, the quality of scientific work leaves much to be desired. The effects of gene editing cannot be judged from mouse tissue samples and just two behavioral tests alone. More extensive and in-depth research is required to understand how possible violations at the molecular level are. After all, data from a number of studies have indicated that mice lacking the CCR5 gene are more susceptible to various viral infections.
Moreover, it became known that the scandalous scientist was trying to modify DNA by completely removing the CCR5 gene from it, and not replacing it with a mutant one. This approach also allows the body to become immune to HIV infection, but it is more dangerous and can lead to unpredictable consequences.
But the biggest problem is that He Jiankuyu failed to avoid gene mosaicism in experiments on monkey embryos. Gene mosaicism - this means that some of the body's cells had DNA with the replacement of the CCR5 gene, and some remained unchanged.
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However, according to He Jiankui, taking blood from the twins' umbilical vein did not reveal any difference in cell DNA. Wang and Yang believe that this is almost impossible. At least the mother's cells with normal DNA must have been present in the blood. Why is mosaicism so dangerous? The risk of dangerous mutations in cells with mosaicism is much higher than in normal cells. Rare congenital anomalies and diseases are associated with mosaicism, which are practically incurable.
Experts believe that He Jiankui is withholding some information about the course of his experiment - that is, he may be an ordinary charlatan.
KARINA GYAMJYAN, K. M. N, DOCTOR-CARDIOLOGIST