Could DNA testing help the most seriously affected Covid-19 patients?

April 28, 2020 – Coronavirus disease 2019 (Covid-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The disease was first identified in December 2019 in Wuhan, the capital of China’s Hubei province, and has since spread globally, resulting in the ongoing 2019–20 coronavirus pandemicCommon symptoms of Covid-19 include fever, cough, fatigue, shortness of breath and loss of smell. While the majority of cases result in mild symptoms, some progress to viral pneumonia, multi-organ failure, or cytokine storm. These more concerning symptoms include difficulty breathing, persistent chest pain, confusion, difficulty waking, and bluish skin. The time from exposure to onset of symptoms is typically around five days but may range from two to fourteen days.

DNA testing could help in COVID-19 patient care

Testing, testing.

Strikingly, it seems that male individuals are much more affected by Covid-19 than female individuals and that the course of the disease is often much much serious, if not fatal in males. This observation is independent from the seeming bias towards the elderly for very serious disease. In this context, the question has arisen whether, besides different physiological. live style (e.g., fuming), and environmental risk factors that may predispose male to Covid-19, underlying genetic factors might play a role. This was the key hypothesis put forth in preliminary research published this month in bioRxiv that highlights the potential benefits of testing Covid-19 patients for genetic variants of the ACE2 gene, that codes for the ACE2 protein (i.e., the angiotensin converting  enzyme 2). ACE2 is already known to be the key point of entry for SARS-CoV-2 into human cells.

What makes the ACE2 gene very interesting in the observation of the startling differences in the Covid-19 death rates between men and women such as noted In the United Kingdom and the United States where men with Covid-19 are dying at twice the rate as women is the that the gene for ACE2 lies on the X chromosome, meaning men and boys only have a single version of the gene, while women and girls have two copies of this gene since they carry two copies of the X-chromosome in contrast to men and boys who carry only one copy of the X-chromosome. Thus, males who carry a rare ACE2 coding variants will express those variants (i.e., ACE2 allelic variants) in all ACE2-expressing cells, whereas females will typically express those variants in a mosaic distribution determined by early X-inactivation events. Recently, rare structural variants of the ACE2 gene have been described in the literature whose expressed proteins show some variations in their binding properties towards the SARS-CoV-2 spike protein. It is possible that in some individuals, if not all, the positive prognosis of the Covid‐19 may be due to the existence of ACE2 variants such as these described variants rs73635825 (S19P) and rs143936283 (E329G). Therefore, the findings of this investigation provide clues to screen frequencies of the candidate alleles in different populations to predict the prognosis of Covid‐19.

Of course, much more research needs still to be done in order to establish the genetics behind Covid-19. Typically, human geneticists would prefer to study the whole genomes of huge number of people infected with SARS-CoV-2 without choosing a preferred (i.e., a candidate  gene such as the ACE2 gene in the present case) gene at the beginning of their studies. That’s the best genetic way to identify factors that might influence why and how sick a patient might get. But during the present Covid-19 pandemic, there may not be enough time or resources to do this. In this situation, relaying on a candidate gene such as the ACE2 gene appears justified and might yield valuable information soon enough to help clinicians and patients alike in prospective disease risk evaluation and in taking treatment decisions. Around the world physicians are already making difficult decisions about who to treat and how; a genetic test around a candidate gene such as ACE2 could arm clinicians with the knowledge they need to intervene earlier in certain cases and thereby save more lives.

The quickest way to find these variants would be to examine the ACE2 gene in unusual cases of Covid-19, taking the so called “extreme phenotypes” approach. For example, children are less likely to come down with severe disease after being exposed to Covid-19, so any child with unusually severe Covid-19 (requiring ICU care, for example), could, in principle, have this gene sequenced where resources allow. Adding up the data from many, many children and adults would then reveal how these rare ACE2 variants truly affect disease severity.

Follow here this short illustrative sequence on SARS-CoV-2:

Print Friendly, PDF & Email

Tags: , , , , , , , , , , , , , ,
About the Author
Joseph Gut - thasso Ph.D.; Professor in Pharmacology and Toxicology. Senior expert in theragenomic and personalized medicine and individualized drug safety. Senior expert in pharmaco- and toxicogenetics. Senior expert in human safety of drugs, chemicals, environmental pollutants, and dietary ingredients.

Your opinion


No comments yet

thasso: conditions

thasso: newest tweets

thasso: recent comments

View my Flipboard Magazine.

thasso: categories

thasso: archives

thasso: simple chat

You must be a registered user to participate in this chat.

  • New COVID-19 related genes—helpful and harmful—found in massive screen October 26, 2020
    Researchers at Yale University and the Broad Institute of MIT and Harvard screened hundreds of millions of cells exposed to the COVID-19 and MERS viruses and identified dozens of genes that both enable the viruses to replicate in cells and also those that seem to slam the door on the virus.
  • Genetic predisposition to increased weight is protective for breast and prostate cancer October 26, 2020
    Although a recent campaign by Cancer Research UK emphasized obesity as a risk factor for cancer on par with smoking, the scientific literature on the relationship between increased weight and cancer risk is not so clear. In a new analysis, researchers from Brunel University London found that increasing weight is causally protective for breast and […]
  • Insights into the genetic architecture of penicillin allergy October 26, 2020
    Researchers announce the first robust evidence for the role of the major histocompatibility complex gene HLA-B in penicillin allergy. To identify genetic risk factors for penicillin allergy, the international team of researchers harnessed self-reported data and the electronic health records of more than 600,000 people, as well as replicating their findings in two independent research […]
  • Breast cancer risk and disease-causing mutations in women over age 65 October 26, 2020
    Women with the onset of breast cancer over age 65 often do not qualify for genetic testing, yet little is known about the frequency of disease-causing mutations in breast cancer predisposition genes in this population. In a new study, researchers investigated the prevalence of disease-causing variants in established breast cancer predisposition genes and estimated the […]
  • Cell-free DNA provides a dynamic window into health October 26, 2020
    Short fragments of cell-free DNA (cfDNA) that circulate in blood, urine, and other biofluids can offer an information-rich window into human physiology and disease. By looking at the methylation markers of cfDNA, researchers can identify the tissue from which the DNA came. A new study used this method to monitor infectious and immune-related diseases, including […]
  • 3D printing the first ever biomimetic tongue surface October 26, 2020
    Scientists have created synthetic soft surfaces with tongue-like textures for the first time using 3D printing, opening new possibilities for testing oral processing properties of food, nutritional technologies, pharmaceutics and dry mouth therapies.
  • Surprised researchers: Number of leopards in northern China on the rise October 26, 2020
    Most of the world's leopards are endangered and generally, the number of these shy and stunning cats is decreasing. However, according to a recent study by a researcher from University of Copenhagen and colleagues from China, leopard populations in northern China are on the mend. Discover why below.
  • Powering the future: new insights into how alkali-metal doped flexible solar cells work October 26, 2020
    A group of scientists from Korea has discovered that the amount of alkali metal introduced into crystals of flexible thin-film solar cells influences the path that charge carriers take to traverse between electrodes, thereby affecting the light-to-electricity conversion efficiency of the solar cell. Given the immense application potential that such solar cells have today, this […]
  • Scientists establish NanDeSyn Database to support international cooperation on industrial microalgae October 26, 2020
    To promote resource sharing and research cooperation for the synthetic biology and molecular breeding of industrial oil-producing microalgae, an international team led by Single-Cell Center (SCC), Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT) of the Chinese Academy of Sciences (CAS), has released the "NanDeSyn Database" (
  • A heart-breast cancer-on-a-chip monitoring system October 26, 2020
    Dual-organ system enables the measurement of cardiac toxicity arising from breast cancer chemotherapy. A collaborative team, which includes a group from the Terasaki Institute for Biomedical Innovation, has developed an organs-on-a-chip system that more widely examines the responses of breast cancer and heart tissues to therapeutic breast cancer drugs.