Another genetic difference that may put people at higher risk of developing severe coronavirus could be one that dictates someone’s blood group, a study in June suggested.
Researchers at genetic testing company 23andMe found that people with type O blood were up to 18 percent less likely to test positive for COVID-19, the disease caused by the virus.
Additionally, those who had the blood type, and had been exposed, were up to 26 percent less likely to contract coronavirus.
The team says this indicates a link between the genes that determined blood type and the severity of the virus. People who become seriously ill are the ones who are most likely to test positive, while milder patients may not realise they’re ill.
For the study, the team recruited more than 750,000 participants, including 10,000 who reported having COVID-19.
Individuals with type O blood were between nine and 18 percent less likely than those with other blood types to test positive.
About 1.3 percent of 23andMe research participants with type O blood tested positive for COVID-19.
By comparison, 1.4 percent of those with type A blood and 1.5 percent of people with type B or type AB blood were confirmed to have the virus.
People with O-type blood who had been exposed to the virus, such as frontline health workers, were between 13 and 26 percent less likely to test positive.
Among those exposed, 3.2 percent with type O blood tested positive compared to 3.9 percent of people with type A blood, four percent with type B blood and 4.1 percent with type AB blood.
The findings, which have yet to be peer reviewed or published in a medical journal, held true when adjusted for factors such as age, sex, body mass index and underlying health conditions.
Researchers identified a variant in the ABO gene, responsible for difference blood types, that was associated with a lower risk.
‘The study and recruitment are ongoing, with the hope that we can use our research platform to better understand differences in how people respond to the virus,’ a statement on the 23andMe blog read.
‘Ultimately, we hope to publish our research findings in order to provide more insight into COVID-19 for the scientific community.’