23andMe’s research that has identified genetic variants associated with the loss of smell or taste due to COVID-19 was published today in the journal Nature Genetics.
As part of 23andMe’s ongoing research on COVID-19, the findings were first reported in June of last year. The paper offers more detail on the study, which identified variants near two olfactory genes — UGT2A1 and UGT2A2.
“We’re delighted to see this manuscript published,” said Adam Auton, 23andMe’s Vice President for Human Genetics. “It is another example of how data contributed by 23andMe customers can provide unique insights into COVID-19. It really wouldn’t be possible without our customers, and we’re extremely grateful to everyone that participated in this research.”
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.
For this work researchers* conducted a genome-wide association study (GWAS) using data from more than 69,000 23andMe customers who consented to participate in research. Along with identifying variants implicating the two olfactory genes, the study also noted that loss of taste and smell after COVID-19 was most common among women and younger research participants. It was less common among research participants of East Asian or African American ancestry.
The research is part of ongoing work by 23andMe since the beginning of the pandemic in 2020. Among the areas of study is research on the role blood type plays in severity and susceptibility to the virus, and insights into the genetics that influence different reactions to COVID-19 vaccines. In addition, researchers are currently studying so-called long haulers, individuals with continued health effects weeks, months or longer after infection, to determine whether genetics plays a role.
For the loss of taste and smell study, the researchers found that about two-thirds of participants who tested positive for the virus reported loss of smell or taste. In addition, the researchers working on this study also ran separate GWAS 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 risk variants for loss of taste or smell most common among people of European ancestry, and least common among those of East Asian ancestry.
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.
Many thanks to the over 1 million research participants who answered our questionnaire and made this research possible.
*The 23andMe COVID-19 research team includes: Adam Auton, Adrian Chubb, Alison Fitch, Alison Kung, Amanda Altman, Andy Kill, Anjali Shastri, Antony Symons, Catherine Weldon, Chelsea Ye, Daniella Coker, Janie Shelton, Jason Tan, Jeff Pollard, Jey McCreight, Jess Bielenberg, John Matthews, Johnny Lee, Lindsey Tran, Maya Lowe, Michelle Agee, Monica Royce, Nate Tang, Pooja Gandhi, Raffaello d’Amore, Ruth Tennen, Scott Dvorak, Scott Hadly, Stella Aslibekyan, Sungmin Park, Taylor Morrow, Teresa Filshtein Sonmez, Trung Le, and Yiwen Zheng.