Genetic risk factor associated with loss of sense of smell or taste in Covid

Science Writing, Jan. 17 (EFE). A team of researchers was able to identify a genetic risk factor that affects a person’s likelihood of experiencing a loss of smell or taste as part of COVID-19 symptoms.

The results of this US study were published Monday in the journal Nature Genetics.

According to the authors, a genetic locus — the exact location on a chromosome where a gene or other DNA sequence is located — located near the UGT2A1 and UGT2A2 genes is associated with an 11 percent increase in the likelihood of developing any of these symptoms — a loss of smell or taste — after infection with SARS. CoV-2.

Confirmation of this genetic link provides clues about the biological mechanisms—which are not yet clear—that underlie the loss of sense of smell or taste, and the characteristic symptoms of covid-19 that, however, not all individuals infected with SARS-CoV-2 have.

The research was conducted using information as of March 2021 provided by 69,841 people (63% women and 37% men) in the US and UK, recruited from the US genetic testing company 23andMe’s customer database.

To reach their conclusions, the scientists conducted a genome-wide association study (GWAS), a method used to try to link disease-specific genetic variations.

Thus, they discovered that a group of variants located near the UGT2A1 and UGT2A2 genes increases an individual’s likelihood of experiencing a loss of smell or taste by 11%.

Both genes are expressed in the olfactory epithelium and play a role in the metabolism of smell.

Although this work provides a genetic link to the biological mechanisms underlying these two symptoms, the authors caution that despite the large sample size, the study is biased towards people of European descent.

It will also be necessary to distinguish between a loss of taste and a loss of smell, which here combine in one question in the surveys of volunteers.

For this reason, they say, it may be beneficial to repeat the study clinically, rather than relying on the participants’ self-reported symptoms. EFE

ng/acm

© EFE 2022. Redistribution and retransmission of all or part of the contents of the Efe Services is expressly prohibited, without the prior and express consent of Agencia EFE SA