Gene Variants Involved in Serious COVID-19 Complications, Study

COVID-19 is still a relatively new, and scientists learn more about it every day. For example, your DNA may affect how vulnerable you are to contracting a COVID-19 infection and how severe that infection may be, according to a study published in Nature. 

The study, led by the Broad Institute of MIT and Harvard and the University of Helsinki (Finland), involved a global research team comprised of more than 3,300 researchers in 25 countries. The study confirmed a link between 13 genetic traits and a higher risk of being infected with SARS-CoV-2 and developing serious complications from it. 

Researchers evaluated clinical and genetic data on 50,000 COVID-positive subjects from 46 studies across 19 different countries. Using more than two million controls across numerous biobanks, clinical studies and direct-to-consumer genetic companies (like 23andMe), researchers were able to run statistically sound analysis quickly and on a wide range of populations. 

Researchers found locations of 13 genes associated with severe COVID-19 complications. Two of the 13 gene locations were more common among people of East Asian or South Asian ancestry. Some results from this study are not necessarily new – they confirmed findings from other studies. Researchers found:

• Gene locations identified with lung cancer, pulmonary fibrosis and some autoimmune diseases (FOXP4, DPP9 and TYK2) are associated with a higher risk severe COVID-19 disease. 
• A genetic connection between lifestyle factors such as smoking and obesity and severe COVID-19 disease. 
• Blood type can affect the risk for contracting a COVID-19 infection. For instance, Type O blood seems to provide a little protection compared to other blood types; this is confirmation of earlier studies.
• A gene variant that disables the TYK2 gene (involved in some autoimmune diseases) raises the risk of critical illness and hospitalization. 
• No association between type 2 diabetes and severe disease. 

Researchers plan to continue studying the data. One priority is studying genes that might be involved in long COVID.  

Other studies have found associations between genes and severe COVID disease. For example, a study published in the New England Journal of Medicine found that patients with the gene for type A blood have a 1.5 times greater chance of contracting COVID-19 and respiratory failure compared to other blood types. 

This study also found that many people with severe COVID disease had gene variants in a particular complex of genes on chromosome 3. Some of the genes encode proteins called chemokines, which interact with immune system molecules. They attract immune cells to tissues under attack, enabling the destruction of infected cells. But in COVID-19, they go into overdrive (cytokine storm), attacking and destroying healthy lung tissue. And another gene variant found was 1.5 times more common in people who had to be put on a ventilator compared to people who just needed supplemental oxygen.    

Researchers cautioned that genetics only make up one risk factor that can contribute to severe COVID illness. Lifestyle and behavior also contribute and can influence your risk of contracting an infection to begin with. Since you can’t control your genetic makeup, it’s important to work with your doctor to manage your chronic conditions and help keep your immune system strong. COVID vaccines remain the best protection against severe COVID illness. If you haven’t already, talk to your doctor about getting the vaccine and continue to follow public health guidelines for social distancing and wearing masks in public.