Common Genetic Variant Linked to Increased Risk of Severe COVID-19
A new study reveals that approximately one in five people carries a genetic variant that increases their susceptibility to developing severe illness from COVID-19, offering crucial insights into why the pandemic impacted individuals so differently.
A study led by the Higher Council for Scientific Research (CSIC) has pinpointed a common genetic variation that affects the body’s initial defense against the virus, potentially leading to more intense inflammation during infection. Published recently in the scientific journal iScience, the research sheds light on a key question that emerged during the pandemic: why some young, otherwise healthy individuals experienced severe COVID-19 symptoms while most others had mild cases.
The Role of the OAS1 Gene in Viral Defense
The research centers on the OAS1 gene, a critical component of the body’s innate antiviral defense. This pathway allows cells to recognize the genetic material of SARS-CoV-2, the virus that causes COVID-19, and initiate an early response to halt its replication. Under normal circumstances, this pathway serves as a first line of defense against infection.
Researchers identified a heritable polymorphism, known as rs10774671, that diminishes the effectiveness of this initial response. Individuals who inherit two copies of this variant produce a less efficient form of the OAS1 protein, resulting in a reduced ability to control viral replication in the early stages of infection.
Genetic Predisposition, Not Deterministic Outcome
While the identified variant increases the probability of developing severe COVID-19, researchers emphasize it is not a definitive predictor of disease outcome. Other factors, such as age, sex, and ethnicity, also significantly influence how a person responds to the virus.
“Having this polymorphism does not necessarily imply that a severe form of the disease will develop,” explained a researcher involved in the study. The team asserts that the genetic factor acts as a risk modulator, rather than a sole cause.
Study Methodology and Findings
To reach these conclusions, the research team analyzed genetic samples from 342 patients between the ages of 18 and 65 who had been infected with COVID-19. The study combined genome sequencing with experiments conducted on human cells and genetically modified animal models.
Results from the animal studies demonstrated that the absence of genes related to this antiviral pathway is associated with a more pronounced inflammatory response, characterized by an increase in cytokines – molecules that, in excess, can trigger uncontrolled inflammation.
Implications for Future Pandemic Preparedness
The authors underscore the importance of understanding how genetics influences responses to coronaviruses. This knowledge is crucial for identifying vulnerability factors and developing targeted prevention strategies for future health emergencies. The identified polymorphism, while of ancient evolutionary origin, does not inherently make carriers more susceptible to illness, but it does contribute to a better understanding of the diverse range of responses to the same infection.
The study involved collaboration between research centers and hospitals, including the Institute of Biomedicine of Valencia (CSIC), the General University Hospital of Alicante, and the La Fe Hospital in Valencia, and received funding from both public and European sources.
Understanding these genetic nuances will be vital as the world prepares for the inevitable emergence of new pathogens, allowing for more proactive and personalized public health responses.
