23andMe COVID-19 Study Finds Genetic Link to Loss of Smell Among COVID-19 patients

SUNNYVALE, Calif., June 7, 2021 /PRNewswire/ -- 23andMe Inc., a leading consumer genetics and research company, today announced 23andMe researchers have identified a new genetic variant associated with COVID-19 induced loss of smell and taste.

The findings, published in a preprint released on medRxiv, note that the genetic variant is near two olfactory genes. Loss of smell and or taste, also called anosmia, is a hallmark symptom of COVID-19. It is often the earliest indication of infection, and in some cases, the only symptom. An individual with one copy of the variant is about 11.5 percent more likely to lose their sense of smell or taste if infected compared to someone with zero copies.

The research builds on the work already done by 23andMe over the last year that includes new findings around the role blood type plays in severity and susceptibility to the virus. Because the novel coronavirus SARS-CoV-2 first enters the body and accumulates in olfactory support cells, the findings may offer researchers important insights into the biological pathway for infection.

For these findings, the researchers again used data from more than one million people who consented to participate in 23andMe's COVID-19 Study. By examining the differences in the genome between COVID-19 cases who did and did not experience loss of taste or smell, 23andMe scientists identified an association on chromosome 4 near the olfactory genes UGT2A1 and UGT2A2.

Two-thirds (68 percent) of those in the 23andMe COVID-19 study who tested positive for the virus reported loss of smell or taste, compared to just 17 percent of those who tested negative. Furthermore, in a model adjusted for other symptoms, age, and sex, the loss of smell or taste carried a seven-fold increased likelihood of testing positive for SARS-CoV-2 among those reporting illness.

The scientists ran separate genome-wide association studies for individuals of European, Latino, African American, East Asian, and South Asian ancestries, and then combined the data via a meta-analysis. The researchers found the frequency of the risk allele is most commonly observed in individuals of European ancestry (37 percent) and least commonly observed in individuals of East Asian ancestry (19 percent).

The researchers also found that among younger people with COVID-19 the loss of smell and taste was more common. Among those aged 26-35, 73 percent reported loss of smell, whereas only 43 percent reported loss of smell in those 85 or older. When the researchers looked at differences between men and women they found that women were more likely than men to report loss of smell or taste (72 percent versus  61 percent).

Little is known about what the genetic variant (rs7868383) does, or how it impacts the likelihood of losing your smell or taste during infection with SARS-CoV-2. But the olfactory genes UGT2A1/2 are part of a family of enzymes called uridine diphosphate glycosyltransferases, and are expressed in the olfactory epithelium and metabolize odorant compounds. In the 23andMe database, both of these genes are related to such things as ice-cream taste preference and ability to smell as measured by a self-reported five-point scale ranging from very poor to very good.

About 23andMe
23andMe, Inc., headquartered in Sunnyvale, CA, is a leading consumer genetics and research company. Founded in 2006, the company's mission is to help people access, understand, and benefit from the human genome. 23andMe has pioneered direct access to genetic information as the only company with multiple FDA authorizations for genetic health risk reports. The company has created the world's largest crowdsourced platform for genetic research, with 80 percent of its customers electing to participate. The 23andMe research platform has generated more than 180 publications on the genetic underpinnings of a wide range of diseases, conditions and traits. The platform also powers the 23andMe Therapeutics group, currently pursuing drug discovery programs rooted in human genetics across a spectrum of disease areas, including oncology, respiratory, and cardiovascular diseases, in addition to other therapeutic areas. More information is available at www.23andMe.com.

SOURCE 23andMe