Researchers used a combination of artificial intelligence and new molecular technology to pinpoint the exact gene – called LZTFL1 – responsible for the increased risks.
They estimate the risky version of the gene is present in about 2% of people from African-Caribbean backgrounds and 1.8% of people of East Asian descent.
The study findings could partly explain the reason for excess deaths in some communities in the UK and the impact of COVID-19 in the Indian subcontinent.
Prof James Davies, a geneticist at Oxford University, Radcliffe Department of Medicine and a senior author of the paper, said: The genetic factor we have found explains why some people get very seriously ill after coronavirus infection. There is a single gene that confers quite a significant risk to people of south Asian background.
The findings needed more confirmation and that genetic explanations should not overshadow other potentially more significant socioeconomic risk factors faced by ethnic minorities, including workplace exposure and unequal access to healthcare.
The gene, which was previously unstudied, was found to act as a switch to turn on a crucial defence mechanism that prevents the coronavirus from entering epithelial cells that line the lung.
Although we cannot change our genetics, our results show that the people with the higher-risk gene are likely to particularly benefit from vaccination” said Davies. Since the genetic signal affects the lung rather than the immune system, it means that the increased risk should be cancelled out by the vaccine.
Unlike the excess risk seen in black populations in the first wave, in south Asian groups there remained a significant unexplained risk once socio-economic factors were taken into account. The Genetic factors would account for a large proportion of that” said Davies.
Raghib Ali, of the University of Cambridge and an independent expert adviser on COVID-19 and ethnicity to the Race Disparity Unit in the Cabinet Office, said: This is an important study which contributes to our ongoing efforts to understand the causes of the higher death rates from COVID in some ethnic groups and specifically as to why their outcomes or survival from COVID are worse after infection.
However, others urged caution. Nazrul Islam, of Oxford University, Nuffield Department of Population Health, pointed out that some ethnicities are not well represented in the large genetic databases used to determine the prevalence of particular genes such as LZTHL1.
The study is published in the journal Nature Genetics
Source: Medindia
