More than two and a half years have passed since the coronavirus outbreak was first reported, and scientists are still unsure why some people are more severely affected by the virus infection than others.
Some previous studies have highlighted that this may be due to the presence of certain gene variants in some humans. Now a team of researchers from the Corporal Michael Crescenz VA Medical Center in Philadelphia has found out that the gene variants that are believed to be linked to COVID-19 severity could also be associated with other known diseases in humans.
In their latest study published in the journal PLOS Genetics, the researchers suggest that understanding these shared genes may reveal new COVID-19 treatment strategies.
How did scientists come across the shared gene variants?
Scientists used an analysis method known as phenome-wide association study (PheWAS) to identify the shared genes. During the analysis, the team of researchers led by Anurag Verma collected genotypic information from electronic health record data (EHR) of more than 650,000 U.S. veterans. This information enabled the scientists to find the links between gene variants responsible for COVID-19 severity in veterans and the gene variants that led to several other medical conditions in humans.
Strong genetic links were discovered for gene variants related to type-2 diabetes, venous thromboembolism (VTE - a condition that leads to the formation of blood clots in 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 chances of falling sick from the coronavirus infection).
According to the researchers, other disorders that share genetic links with COVID-19 severity are chronic alveolar lung disease (COPD), idiopathic pulmonary fibrosis, and chronic obstructive pulmonary disease (COPD). The PheWAS analysis revealed that the shared genes are also associated with neutropenia (low blood count of white blood cells) in veterans having African and Hispanic ancestry. Surprisingly, such genetic links were not found in veterans of European ancestry.
An interesting finding from the analysis was that some of the shared variants responsible for intense COVID-19 sickness actually reduce the risk of autoimmune disorders such as psoriasis and lupus in humans. “The nature of the associations brought to light how the SARS-CoV2 virus pushes on a pressure point in the human immune system and its constant balancing act of fighting infection while maintaining enough control so that it does not also become an autoimmune process, attacking self,” co-author Katherine Liao writes, explaining this strange genetic association.
The significance of these shared genes
The team of researchers at Corporal Michael Crescenz VA Medical Center believes that if the shared genetic variants are identified and studied on a large scale, it can lead to the discovery of new COVID-19 treatment methods. Plus, the variants also hold answers to why some patients are more prone to experiencing deadly COVID-19 symptoms than others.
“The study demonstrates the value and impact of large biobanks linking genetic variations with EHR data in public health response to the current and future pandemics. MVP is one of the most diverse cohorts in the US. We had a unique opportunity to scan thousands of conditions documented before the COVID-19 pandemic. We gained insights into the genetic architecture of COVID-19 risk factors and disease complication,” said Anurag Verma, lead researcher.
Another report published last month in the Nature also highlighted genetic variants linked with COVID-19 severity and disorders such as immune system-driven blood-clotting. For this study, researchers examined genomic data of 7,500 COVID patients who were admitted to intensive care units in the UK ,and compared the same with genomes of 48,000 normal individuals. Their analysis also concluded that an in-depth understanding of the shared genetic variants could offer us new and effective therapies against COVID-19.