A global research project called Mapping the human genetic architecture of COVID-19 (siirryt toiseen palveluun), has identified several genetic risk factors that predispose a person to having more severe forms of the disease.
The study, coordinated by the University of Helsinki and based on a compilation of earlier research data, compared the genetic information of about 50,000 people with Covid-19 with that of a control group.
Thanks to the large body of data, the study provided a broader understanding of the hereditary factors that affect both susceptibility to infection and the severity of the respiratory illness.
"This worldwide collection of data has confirmed many previous discoveries. Additionally, around seven genetic regions were found to carry significance and these can now be studied in more detail," said Mari Niemi, a postdoctoral researcher from the Institute of Molecular Medicine at the University of Helsinki.
The research was led by Andrea Ganna and Mark Daly from the University of Helsinki, and the analysis group includes an international group of volunteer researchers. One of the 46 studies used in the research project was the FinnGen study, which combined Finnish genome and health information.
Blood type does not affect severity of illness
Previous studies have suggested that people with blood type A have a higher risk of developing a more serious type of Covid. However, according to the new study, this is not the case.
"Blood type only impacts susceptibility to infection, but the variance is quite small. Based on this study, blood group A, B or O does not affect the progression of the disease," said Niemi.
The study also sought to clarify whether or not particular genes affect susceptibility and disease severity. It was found that there are several regions in the human genome that can have an impact on disease progression. The most significant discoveries were associated with chromosome 3 and chromosome 6, among others.
Chromosome 3 contains genes that specifically affect the immune system and lung function. Variations in the proteins produced by these genes increase the risk of developing a serious form of the disease. The study confirmed that people with genetic variations in the chromosome 3 region have a 50 to 70 percent higher risk of developing a more serious disease.
A new genetic finding was the area of chromosome 6 that affects the severity of the disease. This is a gene that has previously been linked to lung disease.
No benefit to patients
The results of the study have yet to benefit at-risk people as genetic information is not yet utilized in hospital patient risk assessment. An accurate prediction of who will become seriously ill cannot be made on the basis of genetic information, even in combination with other clinical risk factors, according to the researchers.
"In theory, however, if genetic information were available, this information could also be taken into account when assessing the profile of a person seeking medical treatment," said Niemi.