One study found that a person’s blood type can affect a person’s sensitivity to Covid-19.
Research from genetic testing giant 23andMe Inc. has revealed that differences in a gene that influences a person’s blood type can affect a person’s sensitivity to Covid-19.
Scientists have looked at genetic factors to find out why some people who get the new coronavirus have no symptoms, while others get seriously ill. In April, 23andMe launched a study that aimed to use the millions of profiles in its DNA database to shed light on the role of genetics in the disease.
Preliminary results from more than 750,000 participants suggest that Type O blood is particularly protective against SARS-CoV-2, the virus that causes Covid-19, the company announced on Monday. The results echo other research that has indicated a link between variations in the ABO gene and Covid-19.
Many other groups, including the competitor to 23andMe Ancestry Inc., paint the genome to help understand the virus. It is known that factors such as age and underlying health conditions can determine the fate of people after they contract Covid-19. But these factors alone do not explain the wide variety of symptoms, or why some people get the disease and others do not. Studying the genetics of people most sensitive to SARS-CoV-2 could help identify and protect those most at risk, as well as speed up treatment and drug development.
Several other studies looking at the severity of the disease and the susceptibility to the disease have also suggested that blood type plays a role.
Research published last week before the peer review suggested that blood type may play a role in the severity of patients’ reactions to SARS-CoV-2. This study examined the genes of more than 1,600 patients in Italy and Spain who suffered from respiratory failure and found that having type A blood was linked to a 50% increase in the probability that a patient needs a ventilator. A previous Chinese study found similar results regarding a person’s sensitivity to Covid-19.
“There have also been reports of links between Covid-19, blood clotting and cardiovascular disease,” said Adam Auton, lead researcher on the 23andMe study. “These reports have provided some clues to the genes that may be relevant.”
The 23andMe study, which looked at the sensitivity rather than the severity of the disease, included 10,000 participants who told the company that they had Covid-19.
Research has revealed that individuals with type O blood are between 9% and 18% less likely than individuals with other types of blood to have tested positive for the virus. However, there was little difference in sensitivity between the other blood types, according to the study. When the researchers adjusted the data to take into account factors such as age and pre-existing diseases, as well as when they limited the data to only subjects with a high probability of exposure such as health workers, the results were the same.
Auton said that while this evidence is convincing, much remains to be done.
“This is just the beginning; even with these sample sizes, it may not be enough to find genetic associations,” he said. “We are not the only group looking at this, and in the end, the scientific community may need to pool their resources to really answer the questions surrounding the links between genetics and Covid-19.”
