Yukihide Momozawa, Team Leader

Could you describe your research? What are you trying to understand?

We know that the symptoms of COVID-19 vary from person to person, with some people becoming severely ill and others showing only mild symptoms or being asymptomatic. In general, susceptibility to and severity of infections vary from person to person. One reason for this is individual differences in the genes related to immunity to various viruses. By doing genetic testing and learning the mechanisms that lead to severe disease, we hope to learn how to identify patients who are prone to severe COVID-19.

Why did you decide to do this research?

We know very well that individual differences in genome sequences are associated with differences in susceptibility to and to the severity of many diseases, such as diabetes and cancer. Genomic analysis allows us to comprehensively analyze nucleotide sequences, making it possible to discover the mechanisms behind these differences. We thought we could leverage our expertise in this area for COVID-19.

How will you go about doing this?

In collaboration with Tokyo Medical and Dental University, Hiroshima University and their affiliated hospitals, we are collecting DNA from two groups in an anonymized form. The first group is young COVID-19 patients who theoretically should be at low risk, but who develop severe illness despite not having underlying conditions. The second group is people who never showed symptoms of COVID-19 despite being in close contact with infected people over an extended period. We are analyzing these DNAs using whole genome sequencing to identify individual differences in the genome sequence that are characteristic of patients with severe disease.

How much do we know at this point?

We are participating in a global consortium called the COVID Human Genetic Effort, which has already identified a set of genes that appear to be associated with disease severity (published in Science in October 2020). As our project, we are collecting samples from the Japanese population to find differences in genomic sequences related to the severity of the disease in Japanese people, using the results from the consortium as reference.

What are your future plans?

Since individual differences in genome sequences vary by ethnic group, it is important for us to confirm whether the results reported by the international consortium hold for the Japanese population. It is also possible that we will discover causative genes that are only find in Japanese people. For this reason, we are planning to analyze DNA from a large group of Japanese patients.

The research is being done as an international effort in collaboration with Tokyo Medical and Dental University, Hiroshima University, the National Institutes of Health (NIH), Rockefeller University, and other institutes.