Got COVID with no symptoms? A mutated gene may explain why

Scientists have identified a genetic mutation that is linked to a higher likelihood of a person avoiding COVID-19 symptoms despite being infected.

COVID-19 has left a profound impact on millions worldwide, leading some to require hospitalization, others needing extended bed rest and a significant number who lost their lives. However, there exists a group of individuals who contracted the contagious virus but didn’t experience a single symptom.

Researchers may have unraveled the reason behind this phenomenon: the human leukocyte antigen (HLA), a molecule that assists the immune system during early infections.

A mutated HLA gene could explain why some people never develop symptoms from SARS-CoV-2, the virus that causes COVID-19, even if they were infected.

A study published Wednesday in Nature found that people with the mutated gene, HLA-B*15:01, are more than twice as likely to not get sick from the virus. And those who had two copies of the gene were more than eight times more likely to remain asymptomatic.

“We found that HLA-B*15:01 was significantly overrepresented in asymptomatic individuals relative to symptomatic individuals,” the researchers stated.

“If you have an army that’s able to recognize the enemy early, that’s a huge advantage,” Jill Hollenbach, the study’s lead author and professor of neurology at the University of California San Francisco, said in a media release Wednesday.

“It’s like having soldiers that are prepared for battle and already know what to look for, and that these are the bad guys.”

The gene variant does not stop the virus from entering the body, but it prevents people from developing symptoms like a runny nose, fever or a sore throat.