Scientists have identified a gene that doubles the risk of death from COVID-19 in some patients due to respiratory failure compared with others and it varies widely based on race, according to researchers.

The gene, found by researchers at the University of Oxford's MRC Weatherall Institute of Molecular Medicine in England, is prominent among 60 percent of people with South Asian ancestry in India compared to 15 percent of those with European ancestry.

In the findings published in the Nature Genetics journal, scientists found that an increased risk of severe illness comes from a gene that regulates activity of other genes, including one called LZTFL1 involved in the response of lung cells to viruses.

Scientists had already pinpointed a stretch of DNA on chromosome 3, which doubled the risk of adults under 65 dying from COVID.

But they didn't know until now how this genetic signal worked to increase the risk, or the exact genetic change that was responsible.

Researchers said that the higher risk version of the gene likely prevents the cells lining airways and the lungs from responding to the virus properly. But noted that LZTFL1 doesn't affect the immune system that makes antibodies to fight off infections.

The study also found that two percent of people with black African and Caribbean ancestry in the UK carried the higher-risk genotype.

James Davies, co-author of the study and an associate professor of Genomics at Oxford University's Radcliffe Department of Medicine, said: "The higher risk DNA code is found more commonly in some black and minority ethnic communities but not in others. Socioeconomic factors are also likely to be important in explaining why some communities have been particularly badly affected by the COVID-19 pandemic."

Davies said while nothing can be done to change a person's genetics, the results showed that people with the higher risk gene would benefit most from getting a COVID-19 vaccination.

This, he suggested, is because the genetic signal affects the lung rather than the immune system which means that the increased risk should be canceled out by the vaccine.

The team conducted the research by training an artificial intelligence algorithm to analyze huge quantities of genetic data from hundreds of types of cells from all parts of the body, Oxford said.

This allowed it to show that the genetic signal is likely to affect cells in the lung. The team of scientists also used a technique to zoom down on the DNA at the genetic signal.