Having genetic risk variants in the ABO gene might significantly increase the chances of developing Covid-19, and other genes may also increase the risk, according to researchersDNA is a big, complex molecule and so, genetic associations alone cannot pinpoint the exact gene responsible for Covid-19.

"However, by combining Covid-19 genetic information with gene expression and proteomic datasets, we can figure out which genes are driving the relationship with Covid-19," explained Ana Hernandez Cordero, postdoctoral fellow with the Centre for Heart Lung Innovation, University of British Columbia.

In addition to the ABO gene, the team found that people carrying certain genetic variants for SLC6A20, ERMP1, FCER1G and CA11 have a significantly higher risk of contracting Covid-19.

"These individuals should use extreme caution during the pandemic. These genes may also prove to be good markers for disease as well as potential drug targets," the researchers noted during a presentation at the ATS 2021 International Conference.

Several of the genes identified in the researchers' analysis have already been linked with respiratory diseases.

For example, ERMP1 has been linked to asthma. CA11 may also elevate Covid-19 risk for people with diabetes.

The researchers combined genetic information with an examination of lung gene expression to identify genetic variants that were controlling gene expression in the lung that were responsible for Covid-19.

They identified specific genes' markers that share their effects on gene expression and protein levels with Covid-19 susceptibility.

By doing this, they found that several genes responsible for the immune system's response to Covid-19 are also involved in Covid-19 susceptibility.

"By harnessing the power of genomic information, we identified genes that are related to Covid-19," said Hernandez.

"In particular, we found that the ABO gene is a significant risk factor for Covid-19. Of particular note was the relationship between the blood group ABO and Covid-19 risk. We showed that the relationship is not just an association but causal."

These genes have been linked to severe Covid-19.

"Their role in the immune response to viral infections and mounting evidence suggest that these candidates and their role in Covid-19 should be further investigated," the team said.