Chennai: Research from genetic-testing giant 23andMe Inc. found differences in a gene that influences a person’s blood type can affect a person’s susceptibility to Covid-19.
Scientists have been looking at genetic factors to try to determine why some people who contract the new coronavirus experience no symptoms, while others become gravely ill. In April, 23andMe launched a study that sought to use the millions of profiles in its DNA database to shed light on the role genetics play in the disease.
The research was done on a large scale as it involved more than 7.5 lakh people. Later, by the end of May, the study was expanded further and included an additional 10,000 people who had severe Covid-19 infection. This expanded study is still being carried out.
In the study, the scientists tested the blood samples and the genetic design of these 7.5 lakh people. They were divided into three groups; the ones who self-reported COVID-19 infection, the ones who were hospitalised and the ones who got infected after a known exposure.
The preliminary results of the study suggested amongst all the subjects, people with O blood type were the least likely to get infected. To be specific, they found that individuals with O blood type were around 9-18 percent less likely to test positive for COVID-19 than individuals with other blood types.
The results remained the same even after adjusting the individuals on the basis of age, sex, body mass index, ethnicity, and co-morbidities.
They also found that amongst those who were directly exposed to the infection, such as healthcare workers and other front line workers, people with blood group O were 13-26 percent less likely to test positive for Covid-19 than individuals with other blood types.
The study further indicated that people with blood group AB were the most likely to test positive for COVID-19 infection, followed by blood group B and then blood group A.
The scientists did not take the Rhesus factor (plus or minus blood groups) into account during the study. Previous studies supporting the role of blood groups in Covid-19.
Many other groups, including 23andMe competitor Ancestry Inc., are combing the genome to help make sense of the virus. It is known that factors such as age and underlying health conditions can determine how people fare once they’ve contracted Covid-19.