Sep 28, 2020 13:00:00

Mortality rate of new coronavirus infection may change depending on 'presence or absence of human gene mutation'

The worldwide death toll of the new coronavirus infection (COVID-19)

is close to 1 million at the time of writing, and the World Health Organization (WHO) said, 'Even if a vaccine is developed, the death toll will be 2 million. It could reach people, 'he warns. A research team at Tel Aviv University in Israel has announced that the mortality rate of COVID-19 is associated with 'gene mutations found in some people.'

Ethnic differences in alpha-1 antitrypsin deficiency allele frequencies may partially explain national differences in COVID-19 fatality rates --Shapira ---- The FASEB Journal --Wiley Online Library
https://faseb.onlinelibrary.wiley.com/doi/10.1096/fj.202002097

Carriers of two genetic mutations at greater risk for severe illness and death from COVID-19 --American Friends of Tel Aviv University American Friends of Tel Aviv University
https://aftau.org/news_item/carriers-of-two-genetic-mutations-at-greater-risk-for-severe-illness-and-death-from-covid-19/

The infection rate, severity rate, and mortality rate of COVID-19 vary from country to country, and almost all countries with a mortality rate of more than 100 per million people are in Europe or the Americas. I'm focused. On the other hand, mortality rates in East Asia, Southeast Asia, and sub-Saharan African countries tend to be lower than in other regions.

This tendency may be related to measures such as urban blockade against pandemics, how to maintain social distance, and face mask usage. However, in a new study, the presence of an 'α-1 antitrypsin-deficient allele' that prevents the production of a substance called α-1 antitrypsin in the human body may be related to the mortality rate of COVID-19. It has been pointed out that there is sex.

Α1-Antitrypsin produced by the human body is a major ' protease inhibitor ' that inhibits proteases that have the function of degrading proteins and polypeptides . In addition to protecting human tissues from enzymes in inflammatory cells, α1-antitrypsin inhibits proteases involved in infection with the new coronavirus (SARS-CoV-2) and prevents cells from being infected with SARS-CoV-2. It is known that.

Therefore, the research team used COVID-19 as of September 2020 for the two major gene mutations 'PiZ' and 'PiS' that produce α1-antitrypsin-deficient alleles, using a data set of frequency of occurrence in 67 countries. We investigated the correlation with the mortality rate per million people.

According to the research team, in Belgium, where 17 out of 1000 people have the PiZ gene mutation, the number of deaths per million people was 860. Even in Spain, where the carrier rate of PiZ gene mutation is almost the same as in Belgium, the number of deaths per million people is as high as 640, and the number of deaths in the United States where 15 out of 1000 people have PiZ gene mutation is high. There are 590 people per million. A similar tendency was also seen in the United Kingdom, Italy, Sweden, etc., where the number of carriers of the PiZ gene mutation exceeds 10 per 1000.

On the other hand, in Asian and African countries where PiZ and PiS mutations are relatively rare, the COVID-19 mortality rate tended to be relatively low as of September 2020, the research team pointed out. In Japan, China, South Korea, Taiwan, Thailand, Vietnam and Cambodia, the mortality rate from COVID-19 has been found to be lower than in Europe and the Americas.

This is a graph showing the relationship between the gene mutation that produces the α1-antitrypsin-deficient allele and the mortality rate due to COVID-19. The vertical axis shows the number of deaths per 1000 population, and the horizontal axis shows the number of carriers of PiZ gene mutation and PiS gene mutation per 1000 population, and it can be seen that there seems to be a correlation between the two.

Actually, when arranging the map showing the carrier rate of PiZ gene mutation and PiS gene mutation in each country (top) and the map showing the number of deaths per 1000 population by COVID-19 (bottom), it looks like this .. You can see that the trends are almost the same.

From the results of this study, the research team pointed out that PiZ and PiS mutations may be risk factors for COVID-19. If this finding is supported by clinical trials, it argues that it needs to be linked to a population-wide screening test to identify carriers of PiZ and PiS mutations. The research team said that screening tests could give priority to people who are deficient in α1-antitrypsin due to gene mutations, such as vaccination.