Variation in a genetic mutation may be the reason for the difference in death rates from COVID-19
New Delhi:
Variation in a genetic mutation in Indians may be the main reason for the difference in death rates from COVID-19 in various states across the country, study says that could inform new policies to control the novel coronavirus pandemic .
An international team, led by researchers at Banaras Hindu University (BHU) in Uttar Pradesh, analyzed mutations in the gene responsible for the expression of angiotensin-converting enzyme 2 (ACE2), a protein on the surface of cells that is believed to act as a gateway for the new coronavirus in the human body.
Recent studies have indeed shown that ACE2 is encoded by a gene located on the X chromosome.
In the journal Frontiers in Genetics, researchers looked at the frequency of this mutation described as haplotype rs2285666 in various states of India.
Their spatial analysis showed that in India, the frequency of this haplotype, or a combination of mutations, varied between 33 and 100% depending on the region.
The researchers, for the first time, also found a significant positive correlation for the mutation with lower infection and case fatality rate (CFR) among Indian populations.
Gyaneshwer Chaubey, professor in the Department of Zoology, BHU, said the variations identified reduce a person’s susceptibility to the new coronavirus.
“If in an area more people with this haplotype were present, the contagiousness of the virus would probably be less,” Professor Chaubey, who led the study, told the Press Trust of India news agency.
For example, he noted that Maharashtra and Gujarat, at the state level, have the lowest frequency of gene mutation of around 30-40%, while the Northeast region with a mutation of 75-100 % of the gene has the highest frequency.
“People in western India are more susceptible to the disease than those in central India or eastern India or southern India or northeastern India,” said added Professor Chaubey.
The study adds important potential implications for understanding the patterns of SARS-CoV-2 transmission in various populations around the world, said Anshika Srivastava from BHU, who was also part of the research team.
The researchers noted that when it comes to pandemic control policies, the study suggests that a single rule may not be effective in all states.
They also observed that in both India and Bangladesh, tribal populations have a higher frequency of this haplotype than caste populations.
“If we look at castes versus tribes, tribes have a higher frequency than caste groups,” Mr. Chaubey said, adding that it is likely that tribal people will be less susceptible than caste populations to viral disease.
Further, he noted that strains of virus found in India could also be responsible for contributing to higher death rates, adding that the team is working on the infectivity of various strains of virus found in India as part of the process. ‘an ongoing study.
From the start, it was speculated, and later observed, that the coronavirus affects people differently.
In their previous research, published in the journal PLOS ONE, the team analyzed the genomic dataset of the ACE2 gene from various global populations, with a focus on South Asia.
They found that Indians were closer to East and Southeast Asians, while in terms of ancestry, Indians generally remained closer to Europeans than East and South Asians. -East.
“This unexpected information helped us further explore mutations and haplotypes present in Indians. We found that the associated haplotype rs2285666 increases ACE2 expression,” he said.
“In other words, this mutation reduces susceptibility to the coronavirus,” Mr. Chaubey said.
Noting that the mutation in Indians is 60% and 20% in Europeans, Chaubey said this implies that Indians are less susceptible to COVID-19 than Europeans and Americans.
“Surprisingly, we found that the geographic distribution of this haplotype was strongly correlated with the number of cases as well as the CFR (death rate),” Mr. Chaubey said.
“Where the frequency of this genetic factor was high, cases and CFR were less and vice versa,” he noted.
Although data has accumulated, the expression of the ACE2 gene variation affecting host susceptibility among various populations worldwide is not yet known.
“Genetically, most South Asians are more related to Western Eurasian populations than to East Eurasians, while for this gene the result is contradictory,” added University Professor George van Driem. from Bern in Switzerland, co-author of the previous study. .
The researchers said there were a few studies on the ACE2 gene by other groups, but all looked at differences in the frequency of various mutations, while the team used a more powerful analysis based on haplotypes.
(Except for the title, this story was not edited by GalacticGaming staff and is posted from a syndicated feed.)
