Loss of smell and taste in corona infection - researchers finally announce new findings after the study

Created: 01/19/2022 13:44

By: Elena Royer

Many people suffering from Corona report a loss of smell or taste.

But not everyone is affected.

A new study is now available.

California - Smell and taste are two important senses that play a particularly important role when eating.

A phenomenon that often accompanies a corona infection is the loss of these two senses.

Researchers in the USA have now discovered that this phenomenon probably also depends on the genes.

Smell disorder in corona infection: Genes are probably partly to blame

This is the conclusion of a study recently published in the journal

.

Almost 70,000 people took part.

A loss of the sense of smell or taste was the first sign of infection early on in the corona pandemic*, but the cause of this has not yet been clarified.

It is also unclear why some infected people have an impaired sense of smell and taste, while others do not.

Corona: Study brings new results on the loss of the sense of smell

To find out, the researchers conducted a genome-wide comparative study with 69,841 participants.

All participants were over 18 and lived in the US or UK.

According to this, 68 percent of those surveyed who had already been infected with the corona virus experienced an impairment in smelling or tasting during the infection.

The researchers compared this group with those who did not suffer from a loss of smell or taste during their corona infection.

They did this by comparing gene variants in the entire genome of the study participants to find out whether genetic factors are responsible for the loss of smell or taste.

Change in a gene locus probably responsible for the loss of smell

Using special algorithms, the scientists looked for gene locations that were changed more often in the participants with a loss of smell or taste than in those without this phenomenon.

And they found what they were looking for: in those study participants who suffered from a loss of smell after a corona infection, a gene location was changed more frequently.

This section of DNA includes 28 variants.

According to scientists, these variants would increase the risk of losing the sense of smell by around eleven percent.

Europeans particularly affected by olfactory disorders?

The genetic association is clearest in the European population, but the effect sizes are consistent across populations, the scientists said.

This fits with the results of the survey that people of European descent are more often affected by a loss of smell in a corona infection than people with Asian or African ancestors.

, the affected gene location is

close to two genes, UGT2A1 and UGT2A2, which are important for smell perception.

These genes are mainly active in the nasal cavity and contain the building instructions for enzymes that are important for smell perception.

These enzymes are specifically responsible for binding to and neutralizing odors that have already been decoded and perceived by humans.

As a result, these odorous substances become invisible to the olfactory receptors, which are only then able to perceive new scents.

This is important so that scents do not get caught in the nose and other smells cannot be perceived.

The enzymes ensure that the smell disappears as soon as the triggering smell is no longer present in the environment.

How are the results related to Corona?

How exactly the two newly identified genes UGT2A1 and UGT2A2 are responsible for the loss of the sense of smell and taste has not yet been clarified.

However, the researchers suspect that the genes may play a role in the physiology of the infected cells, based on their location and essential function.

This could result in the functional impairments that result in the loss of olfactory perception.

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