People with one of eight genes found on seven chromosomes are at much higher risk of dying from Covid-19, study shows
- Individual presence of super-variants slashes likelihood of survival
- Having three of them sees survival likelihood plummet to as low as 60 per cent
- Data comes from more than 1,700 cases of Covid-19 from the UK Biobank
Scientists have identified eight genes that have a major influence on a person’s likelihood of survival if they become infected with the coronavirus.
Faulty versions of these genes, known as super-variants, were discovered scattered across seven chromosomes by researchers at Harvard University.
Having just one of these faulty genes can slash the chance of survival by at least 20 per cent.
But having three or more can see survival likelihood plummet to as low as 60 per cent.
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Just having a single version of the faulty genes can slash the chance of survival by at least 20 per cent. Having three or more of the dodgy genes can see survival likelihood plummet to as low as 60 per cent (pictured)
Data from the UK Biobank, released in August, allowed researchers to scrutinise the genetics of 1,778 people who contracted Covid-19. Of these, 445 people died, making just over a quarter of the study cohort (file photo)
Data from the UK Biobank, released in August, allowed researchers to scrutinise the genetics of 1,778 people who contracted Covid-19.
Of these, 445 people died, equating to just over a quarter of the study cohort.
A computer scanned through the genomes of the infected people and looked for genetic locations which crop up that may be linked to mortality.
This revealed the eight ‘super-variants’, which are different to traditional genes as they are not bound to a specific physical location.
Super-variants involve various pieces of DNA, which are scattered across the same chromosome and work together to execute their normal function.
Pictured, the impact of a super-variant on the likelihood of survival in Covid-19 patients. The red line indicates their chance of survival after infection whereas the dotted blue line shows what their chance of death would be without the faulty gene
The study, available on medRxiv, which has not yet been peer-reviewed, explains that the super-variant is powerful and stable because it ‘aggregates the strength of individual signals’.
‘The most interesting signal 222 appears on chromosome 2 in the super-variant chr2_197,’ the researchers declare in their study.
The frequency of having this super-variant among men and women is 18.09 per cent and 22.93 per cent respectively, the researchers say.
It is linked to the gene DNAH7, which is involved in controlling the movement of cilia – tiny hairs in the respiratory tract that help move mucus.
A previous study found this gene is heavily down-regulated after infection with SARS-CoV-2, the virus which causes Covid-19, stopping it from working properly.
According to the new study, having a specific type of this gene makes people around 25 per cent more likely to die from Covid-19 after 20 days.
According to lead author Jianchang Hu and colleague, who led the study, this variant can be lethal because the virus uses it to disable a person’s ability to clear mucus via the cilia ‘which leads to severe respiratory failure, a likely cause of COVID-19 death’.
Cilia function is also impacted by another of the super-variant genes, called chr16_4, which inhibits the creation of the vital structures.
Chr16_4 leads to an approximate drop in survival rate to 70 per cent, whereas people without the variant have an 85 per cent chance of survival.
‘It is noteworthy that both super-variants chr2_197 and chr16_4 are related to cilia, which plays a crucial role in SARS-CoV-2 infection,’ the researchers say.
However, while having a single super-variant lurking in your DNA increases the chance of death from the disease, having more compounds the issue.
‘The survival probability of patients with more than 3 super-variants dramatically decreases to around 0.6 during the first three weeks,’ the scientists say.
BAME people are NOT genetically more at-risk of dying from Covid-19
Black, Asian, and minority ethnic (BAME) people are not genetically more at-risk of dying from Covid-19, a new study has concluded.
BAME communities are two to three times more likely to die from coronavirus than other members of the population, analysis of NHS data has previously revealed.
However, scientists in Japan and the US found no differences in seven genes associated with viral entry of SARS-CoV-2 – the virus that causes Covid-19 – across ethnic groups.
Pre-existing medical conditions and environmental factors are more likely to blame for people of ethnic minorities being more likely to die of the disease, they say.
Public Health England has also reported the mortality rate – the number of people dying with the coronavirus out of each 100,000 people – is more than three times as high for black men than other groups.
Although BAME people are not considered genetically more at risk of Covid-19, it’s been suggested minority ethnic people have had less access to medical resources during the pandemic and live in densely populated areas, causing fast transmission.