Gene Changes Affect COVID-19 Severity and Immune Response

Have you ever wondered why some people get really sick from COVID-19 while others barely notice it? A lot has to do with our genes. Scientists looked into how changes in two genes, FAS and FASL, affect how severe COVID-19 can be and if it leads to long-term symptoms. These genes play a role in T-cell death, which can cause lymphopenia, a condition where you have fewer T-cells. They studied 116 people with severe COVID-19 and 254 with milder cases. After recovery, they checked 196 people with long COVID and 67 without. They found that specific changes in the FAS and FASL genes were linked to higher levels of these genes being expressed. This means the genes were more active.Higher activity of these genes was also tied to higher levels of a protein called IFN-γ in the blood. IFN-γ is involved in immune responses and inflammation. Patients with milder COVID-19 who had these gene changes had more symptoms and higher IFN-γ levels. Interestingly, these gene changes didn't seem to affect long COVID. So, changes in FAS and FASL genes can make COVID-19 more severe by increasing inflammation and T-cell death. But why these gene changes happen and how they exactly influence the disease needs more research.