An international team of researchers has uncovered two genetic loci associated with COVID-19 severity, The Scientist reports.
Researchers led by the University of Oslo's Tom Hemming Karlsen conducted a genome-wide association study of nearly 2,000 COVID-19 patients from Italy and Spain with respiratory failure. As they report in a preprint posted to MedRxiv, they compared these patients to population controls, also from Italy and Spain, to find two loci that reached genome-wide significance. One locus encompasses the SLC6A20 gene, which encodes a protein known to interact with ACE2, the receptor SARS-CoV-2 uses to enter host cells. The other region includes the ABO blood group locus, and the researchers' analysis suggests individuals with blood type A are at greater risk of more severe COVID-19 and that blood type O may be protective.
"Each variant found here only increases a person's risk a little bit, and we have no idea how," Charlotte Houldcroft, who was not involved in the study, tells The Scientist. "It doesn't allow us to predict who will be a severe case, and it doesn't open up any treatment options. However, it does give us a plausible place to start looking."