More than two and a half years have passed since the coronavirus outbreak was first reported, and scientists still don’t know why some people are more severely affected by the viral infection than others.
Some previous studies have shown that this may be due to the presence of certain genetic variants in some humans. Now, a team of researchers from Corporal Michael Crescenz VA Medical Center in Philadelphia has found that genetic variants believed to be linked to the severity of COVID-19 may also be associated with other known diseases in humans.
In their latest study published in the journal PLOS geneticsresearchers suggest that understanding these shared genes could reveal new treatment strategies for COVID-19.
How did scientists discover shared genetic variants?
The scientists used a method of analysis known as phenome-wide association study (PheWAS) to identify shared genes. During the analysis, the team of researchers led by Anurag Verma collected genotypic information from electronic health record (EHR) data of more than 650,000 US veterans. This information has allowed scientists to find the links between the genetic variants responsible for the severity of COVID-19 in veterans and the genetic variants that have led to several other medical conditions in humans.
Strong genetic links have been found for genetic variants linked to type 2 diabetes, venous thromboembolism (VTE – a condition that leads to blood clots forming in the veins) and ischemic heart disease. Interestingly, the first and last disorders are well-known COVID-19 risk factors (medical conditions that increase a person’s chance of getting sick from coronavirus infection).
Other disorders that share genetic links with COVID-19 severity are chronic alveolar pulmonary disease (COPD), idiopathic pulmonary fibrosis, and chronic obstructive pulmonary disease (COPD), researchers say. PheWAS analysis found that shared genes are also associated with neutropenia (low white blood cell count) in veterans of African and Hispanic descent. Surprisingly, such genetic links have not been found in veterans of European ancestry.
An interesting finding from the analysis was that some of the shared variants responsible for intense COVID-19 disease actually reduce the risk of autoimmune diseases such as psoriasis and lupus in humans. “The nature of the associations has shed light on how the SARS-CoV2 virus exerts pressure on a pressure point in the human immune system and its constant balance of fighting infection while maintaining sufficient control that it does not also become an autoimmune process, attacking itself. writes co-author Katherine Liao, explaining this strange genetic association.
The importance of these shared genes
The team of researchers at Corporal Michael Crescenz VA Medical Center believe that if shared genetic variants are identified and studied on a large scale, it may lead to the discovery of new methods of treating COVID-19. Additionally, the variants also contain answers about why some patients are more likely than others to experience life-threatening symptoms of COVID-19.
“The study demonstrates the value and impact of large biobanks linking genetic variations to EHR data in the public health response to current and future pandemics. MVP is one of the most diverse cohorts in the United States. We had a unique opportunity to scan thousands of conditions documented before the COVID-19 pandemic. We have gained insights into the genetic architecture of COVID-19 risk factors and disease complications,” said Anurag Verma, lead researcher.
Another report published last month in the Nature also highlighted genetic variants linked to the severity of COVID-19 and disorders such as immune-mediated blood clotting. For this studyresearchers looked at genomics data from 7,500 COVID patients who were admitted to intensive care units in the UK and compared the same with the genomes of 48,000 normal individuals. Their analysis also concluded that a deeper understanding of shared genetic variants could offer us new effective therapies against COVID-19.