A team of scientists has discovered a genetic risk factor that causes people with COVID-19 to lose their sense of taste and smell. A new study published in the journal Nature Genetics detailed two genes that may play a role in why some people lose one or both of those senses and others don't.
They noted that 68% of nearly 70,000 individuals who self-reported testing positive for COVID-19 suffered a loss of smell or taste.
"How we get from infection to smell loss remains unclear," Dr. Justin Turner, an associate professor of otolaryngology at Vanderbilt University, told NBC News.
"Early data suggests that supporting cells of the olfactory epithelium are the ones mostly being infected by the virus, and presumably this leads to the death of the neurons themselves," he said. "But we don't really, really know why and when that happens, and why it seems to preferentially happen in certain individuals."
The researchers said that the two genes "are expressed in the olfactory epithelium and play a role in metabolizing odorants." They noted that the presence of those genetic markers increases the likelihood of experiencing a loss of taste or smell by 11%.
They hope that their research will lead to potential treatments for the condition, which continues to linger in some people for several months.
According to a different study published this past November, 1.6 million Americans continue to report a loss of taste or smell six months after being diagnosed with COVID-19. Some of those people say their sense of smell has returned but noted that things smell differently than before their infection.