Tuesday , March 2 2021

Change of human gene genome: A concern caused by Chinese scientists, gene-regulated babies



Scientists in Hong Kong warned of the far-reaching effects on people and the consequences that will not be seen over several generations after a Chinese scientist claimed to have created the first baby in the world.

Dr. He Jiankui's experiment to modify the twin baby DNA – also known as germanic genetic regulation – means that the changes in this genome could be transmitted and inherited by the next generation.

"Working on it, He changes the human genetic gene, we may not be able to see the impact of this for up to several generations later," said Dennis Lo Yuk-ming, chairman of the China University of Chemical Pathology.

"Academically, there is no consensus on what we need to do and technology is not yet fully there – how to do it now, it's very irresponsible," Lo said on Thursday, the last day of the Hong Kong International Genome Summit.

It was expected that scientists and experts would make formal statements about the regulation of genes, including what is acceptable and how the trials can be regulated.

He, who had previously launched an international debate after unprecedented disclosure of his trial, defended his research at a summit on Wednesday and discovered that there was another potential pregnancy of gene edibrium.

He used the tool for editing the CRISPR gene, a method that facilitates and accurately alters the genes that have emerged in recent years. He hoped that the modification would make twins, Lulu and Nano, resistant to HIV infection.

However, such technology has not matured, which could result in genes that were not the target of an experiment that is also changing.

"There may be side effects, for example, if it affects other genes that relate to cell reproduction, it can lead to cancer," Lo said.

The late physicist Stephen Hawking, in a series of essays and articles published posthumously, predicted that genetic engineering would lead to the race of "superhuman", by regulating the properties of intelligence and the instincts of aggression. He was worried that this ability would be concentrated in the hands of rich and powerful.

Another expert, Derrick Au Kit-sing, director of the CUHK Center for Bioethics, said the experiment was "too early".

"Even while this research is done on animals, we have no idea what the long-term consequences will have-let alone know if it's safe to do it," Au said.

"The entire scientific and medical community believes that this has happened prematurely, we simply have no idea of ​​future risks," he said.

His research, published on Monday, prompted a swift global condemnation with the Chinese Ministry of Science and Technology to investigate whether it violated the law. Critics say that research is not medically necessary because the risk of HIV can be reduced or prevented by other methods or treatments.

Au also raised the question of whether ethical for the respondent was engaged by the HIV / AIDS Advocacy Group.

"It seems ethically problematic to find those so-called volunteers doing this experiment, because they are people who are more vulnerable, they could easily manipulate and influence them," Au said, adding that he asked if couples really understood the experiment and knew risks.

The Hong Kong Law prohibits work on embryos that allow it to develop for more than 12 days, says the Human Reproduction Technology Council.

Modification of a gene that results in live birth is banned in several countries, including China, for security and ethical issues.

His seven-pair clinical trial was put on hold after the controversy broke, but said he would continue to monitor twins up to 18 years.

What is genetic regulation? Who does it? Is that correct?

Scientific community is heavily threatened by the fortress that a woman in China gave birth to the first genetically-regulated babies earlier this month, born of embryos modified to make twins resist HIV-infection.

The announcement was made by Chinese scientist He Jiankui on Monday, ahead of a second international genomic humanity summit held in Hong Kong, where world leading thinkers on the ground came closer to discuss technology and its ethics.

His claim deepened the sense of urgency about the debate about the morality of editing the gene, the one that has intensified rapidly in technology over the past few years.

These advances are largely the result of the discovery of a powerful tool for editing the genes known as CRISPR-Cas9, whose genetic-genetic applications were first identified by the University of California, Berkeley Biochemist Jennifer Doudn and Emmanuelle Charpentier, director of the Max Planck Institute for Biological Infection Berlin.

Although technologies that allow scientists to regulate DNAs in development since the 1970s, the CRISPR-Cas9 discovery has accelerated scientists' ability to improve crops, control infection, and eliminate hereditary diseases. It also opens the door to radical changes in human DNA – this was the technology allegedly used by He to prevent a newborn baby from inheriting HIV infection.

What is genetic regulation?

Genes are sequences encoded in DNA cells; they determine the characteristics of the organism, the development, and in some cases, and which diseases they will receive. Scientists have the ability to change the DNA sequence or gene within the living cell, "edit" the gene and change how it is expressed in the body. With genes editing, scientists can replace DNA building blocks of genes for the production of a disease for a new non-pathogenic genetic code.

"Genome" is a broader term that refers to the entire DNA sequence of the organism or the entire map of the pathway for the organism. Using techniques such as CRISPR-Cas9, scientists now have the power not only to engineer the expression of a particular gene, but to target more genes on DNA days, thereby creating a greater impact on the genome.

What is CRISPR-Cas9?

CRISPR-Cas9 is a molecular system that acts as a pair of very precise scissors, setting the right place at the bottom of the DNA to cut the gene and insert its replacement. It is a tool that is borrowed from the immune system found in bacteria, where CRISPR molecules have kept the genetic code from past infections to defend against them. When scientists learned, CRISPR molecules can match and find DNA sequences, while Cas9, its accompanying enzyme, binds and reduces DNA.

Other DNA repair enzyme techniques existed before 2012 and are still used, such as zinc-ring nuclei (ZFNs) and effector nucleases such as transcription (TALENs), but they are considered less precise and expensive for laboratories to be used in comparison with CRISPR-Cas9.

How advanced is the technology for genome editing today?

The CRISPR technique is already used to change plants and animals. Earlier this year, researchers at Imperial College London used this technology to find a key that could wipe out the world's mosquito population, while they were producing virus-resistant viruses at the University of Edinburgh. There are numerous farming applications from non-brown mushrooms, created by Professor State University in Pennsylvania in 2016, to paradise plants with less gigantic branches, developed by scientists from the Cold Spring Harbor Laboratory in New York. The products of these advances at this time are limited to laboratories.

The use of CRISPR and similar technologies in the fight against human diseases is one of the most unlikely potential applications that fund research and the attention of scientists. The widespread use of CRISPR means that laboratories around the world are using it to see how genetic regulation can remove the disease from haemophilia to HIV. Chinese scientists were the first to experiment with injection of cells with the CRISPR-modified genome directly into humans. They used a gene removal technique that stops the immune system of the body that attacks the cancer cells in a clinical trial in 2016 with a lung cancer patient at Sichuan University in Chengdu. Last year, a California-based private company made the first attempt to allow proteins to regulate genes directly inside the body, instead of modifying cells and then injecting them in an attempt to stop the genes that produce Hunter syndrome. This procedure did not rely on CRISPR, but on the ZFN.

At the very top of the genome editing technology is the modification of the human embryo. Although this technology causes fears from "designer babies" with DNA altered to improve their appearance or intelligence, the Scientific Council has focused on embryonic experiments on the prevention of hereditary disease. The first known experiments on edible embryos were published by Chinese researchers at Sun Yat-sen University in Guangzhou in 2015, only three years after the discovery of CRISPR-Cas9 technology. The first embryos were edited last year by CRISPR in the United States researcher at the University of Oregon Health and Science University, who successfully removed genes associated with inherited diseases.

These exercises were purely experimental until it was claimed to have implanted a gene-modified embryo for twins in a woman.

Why is gene control controversial?

When scientists regulate the human embryo, they create changes that have the potential to affect the genetic makeup of future generations. Unlike changes made to developed human cells, which will affect only the person being treated with these cells, changes in sperm, egg cells or embryos can be inherited. Scientific bodies globally said that such heavy impact was carefully considered and discussed with the public before it was used.

When it comes to the current controversy surrounding He, the second is ethical consideration of health. Since technology is so new, the effects that a change process may have on the DNA and resulting human life are not known. Scientists around the world ask if he has carefully considered the future baby's health before using this new technology.

The birth of twins strikes at the heart of the problem of "baby designers" who often express themselves about genome regulation. However, the physical and personality attributes are usually associated with multiple genes, so that while the human genome can be edited, choosing for such effects will be complicated to withdraw. For now, science has focused its experiments on the elimination of the disease, rather than on the choice of desirable features.

– South China Morning Post


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