Since the first moment that “Covid-19” came out of China, in January 2020, the eyes of the whole world have turned to the death rates and categories, although the disease in the vast majority of cases passes without symptoms or like a cold that is more severe than usual For, about a fifth of the cases require hospitalization, and a quarter of these cases face critical problems that may ultimately lead to death.
Our first information about the risk was related to (1) age and disease category, as it became clear during the first weeks of spread in China and around the world that people over the age of fifty are more likely to develop serious symptoms of the disease, with rates of severity that increase with age, especially if it is of advanced age. Concurrent with chronic diseases such as diabetes, high blood pressure, or heart, kidney and liver diseases in general, people with these diseases, even if they are in lower age groups, are exposed to a greater rate of serious symptoms of the disease, up to death.
Then appeared a correlation of the dangerous symptoms of “Covid-19” with other diseases (2), including of course most categories of lung diseases from asthma to cancer, and those who suffer from weak immunity for one reason or another (usually they receive immunosuppressive drugs due to disease Immunological), and in spite of all the relationships that are not yet understood, for example, it has become clear that the disease is more severe in obese people of all ages, and it has also been shown that the serious symptoms of the disease affect men slightly greater than women.
But despite all these results, it represented about 95% of all critical cases and deaths due to “Covid-19 ″”, and the rest were for people without the main risk groups, people belonging to small age groups, completely healthy and perhaps they were athletes, and did not suffer From any chronic disease, yet the disease was able to kill them, at that specific point geneticists intervened to answer the new question: Can genes play a role in determining the severity of “Covid-19” cases?
Well, DNA is simply the code of life, and it consists of a very long line of complex chemical letters present in all the cells of your body, let’s imagine that it is a long tape of one of the old videos, along the line of this brown tape various scenes are recorded, here, for example, he meets the hero With the heroine for the first time, and there he leaves her to travel in search of money, in another piece of the tape he returns to her in great regret.
DNA also consists of codes or codes that you inherited from your parents, here is a code that determines your height, there is another code that determines the color of your eyes, and a third code determines the nature of your hair. In biology, these codes have a well-known name: genes, which translate into the components of your body and its mechanism of action, so any possible tampering with genes is tampering with your body and its mechanisms of action.
One of the first to be interested in the hypothesis of the relationship between genes and “Covid-19” was John Laurent Casanova, a professor at the American Rockefeller University, who examined, over several decades, a strange link that no one expected to exist, for we know that there are diseases, such as hemophilia or anemia falciparum, a person inherits it from his parents, but no one would have thought that infectious diseases might have a genetic or hereditary aspect.
According to Casanova, there are a number of defects in the genes responsible for the human immune system (which number two thousand of about 25 thousand genes in a person), which can prevent it from dealing with a number of viral infections effectively, which pushes the disease to penetrate more heavily in the patient’s body. And here, serious symptoms of disease appear, as well as death, some of these species Casanova calls “Mendelian Infections” (3).
In a research paper published in September 2020 in the prestigious journal “Science”, Casanova, along with a large team of researchers, conducted (4) genetic analysis of blood samples of more than 650 patients who were hospitalized due to severe pneumonia associated with “Covid-” 19 “(14% of them died later), with samples from another group of more than 530 people infected with asymptomatic” Covid-19 “.
The team (5) looked for differences between the two groups across 13 genes that play a role in the body’s defense against the influenza virus, and they found a clear difference in a number of genes that are actually responsible for producing a system made up of 17 proteins called “type I interferons”. They play an important, very early, role in defending against viruses attacking the body and stimulating other immune factors. In some patients, interferons are not produced at all.
This was followed by a research focus on that point that a few months ago was neglected due to the chaos of the disease spreading in an accelerated pattern, as a research team (6) examined the last larger sample, consisting of about 1900 people with severe cases infected with the emerging corona virus in Spanish and Italian hospitals, the study approved According to previous analyzes, there is a preference for people with type O blood compared to people with type A, which raises the risk by 50%.
This study showed that there are several genes, on a site in the third human chromosome (and chromosomes are – to simplify – the forms that genes take when they are stored in cells) that are related to the risk of “Covid-19 ″”, which are the same genes responsible for blood types, which means That there may indeed be a direct relationship between the genes in our DNA and degrees of risk of varying severity, up to death, in cases of “Covid-19”.
Recently, a team from the Genomic Consortium (GenOMICC) – a global collaboration to study the relationship between genetics and serious diseases – reached specifically five genes (7) that are directly related to serious injuries, and it has been shown to them that the problem is related to two aspects of the physical response, the first related to Immunity and its capabilities to repel aggression (the virus) in an appropriate manner, are not more or less than normal, and the second is related to the inflammatory response to the disease when it occurs in the body.
So far, this sample is considered the largest in this range, as the team examined 2,700 patients in 208 intensive care units in the United Kingdom, and compared their genetic tests with a number of healthy subjects, showing that defects in the genes called “IFNAR2 ″, TYK2 ″ and OAS1” And “DPP9” and “CCR2” may be related to severe and critical symptoms of “Covid-19”.
This group of genes was really remarkable (8), one of which, for example, is “TYK2”, responsible for the amount of the immune response to the virus, but in terms of ferocity, if this gene is defective, the immune response will not be limited to resistance to the virus attacking the body, But it will extend to attacking and damaging the body itself, which causes severe infections associated with the disease in the lung, heart and kidneys, called “cytokine storm”, and it is now known that it is the main cause of death for patients in severe cases of the disease.
On the other hand, the gene called “DPP9” plays a role in determining the amount of inflammation that is produced during the battle between our immune system on the one hand and the virus on the other hand, and the group of genes called “OAS”, whose greater representation produces mechanisms that help prevent The virus copies itself inside the body, and the “IFNAR2” gene comes to confirm the Casanova study that we talked about a while ago, as it helps to produce interferon early, which in turn helps activate the immune system as soon as the infection is detected.
Of course, we cannot make a definitive and definitive link between genes and those cases in which “Covid-19” kills families while it passes peacefully on other families, due to the complexity of risk criteria for the disease, which include social and demographic factors, and reach gender and race. Income and access to quality health care, all of which play major roles in determining how this epidemic affects people.
In addition, even after reaching these results, direct assertions, that is, linking a specific gene to its specific effect on the course of the disease and its severity, are still absent, but day after day the researchers collect results that tend towards the presence of genetic factors associated with more symptoms Dangerousness of “Covid-19” and the death rates due to it.
But in the end, the importance of this type of discoveries of genetics does not stop only when explaining why some genetic factors may be related to the severity of the infection, but it may also one day be a reason for the production of new drugs that treat the disease, or directing drugs that were It already exists and is used in the treatment of other diseases in terms of “Covid-19”.
At that point, a drug (9) is already being used in conditions such as rheumatoid arthritis, called baricitinib, that can help as an anti-inflammatory that is caused by defects by the TYK2 gene, and interferon therapy may prevent the defects. In the gene “IFNAR2”. Currently, the “Genomic” team is working to direct a group of drugs already used in other diseases towards “Covid-19” because of their effects that help against defects in these genes.
Although we now have vaccines capable of resisting, obtained by more than a billion people around the world, they will not be the only line of defense against a disease that seems to continue with us for many years as a heavy guest that knocks our lives from time to time, and perhaps even after that pandemic ends. That continues to hit our world hard, and relentlessly.