For nearly two years of the Covid-19 pandemic, scientists have been trying to work out why some groups of people are more at risk of developing acute and potentially fatal symptoms.
A recent study pinpoints a specific gene as a “candidate effector gene” that could be responsible for the development of critical complications in some people infected with the novel coronavirus that causes Covid-19.
The study, led by scientists at the University of Oxford, was published in the journal Nature Genetics. Several Arab scientists commented to Al-Fanar Media on the study’s implications.
The study found a gene known as LZTFL1 was associated with increased incidence of critical symptoms such as respiratory failure among people infected with Covid-19. The study attributed this to the gene’s role in preventing the cells lining the respiratory system from responding properly to the virus. The gene increases the cells’ production of a protein known as the ACE2 receptor on their surfaces, helping the virus attach to the cells and spread the infection more efficiently.
The study also found ethnic variations in the gene’s distribution. About 60 percent of British people of South Asian descent had increased levels of the gene, compared to 15 percent of those of European descent. This may partly explain the higher death and hospitalisation rates in some communities in the United Kingdom, and the impact of Covid-19 on the Indian subcontinent, whose population is more vulnerable to critical complications.
Genetic Factors and Disease
Bakhos Tannous, a Lebanese-American professor of neurology at Harvard Medical School, told Al-Fanar Media: “Genetic factors influence infections with several viruses, such as influenza virus (H1N1), known as the 2009 swine flu pandemic, Ebola, and the human papillomavirus (HPV).”
“Genetic factors influence infections with several viruses, such as influenza virus (H1N1), known as the 2009 swine flu pandemic, Ebola, and the human papillomavirus (HPV).”Bakhos Tannous
A Lebanese-American professor of neurology at Harvard Medical School
While the Oxford study focuses on LZTFL1 as a contributing factor in Covid-19 complications, Tannous noted that this gene has beneficial functions in other diseases. “It plays a positive role in preventing cells from turning into cancerous ones more quickly,” he said. “The increased production of the ACE2 protein grants the carriers of this gene a greater immunity to the rapid multiplication of malignant cells.”
Mona Kayal, a microbiologist and consultant doctor in viral and bacterial diseases at Prague University Hospital, said: “It seems that there is a genetic predisposition for some people or some ethnicities that may contribute to an increased risk of complications when infected with viruses like the ones causing Covid-19, influenza and others.”
Kayal pointed to studies that have found a possible relationship between certain genes and the severity of infection if you compare the human genome of those who had severe symptoms with those who did not develop them.
However, she stressed that other risk factors seriously increase the incidence of complications. These include “advanced age, severe obesity, diabetes, heart diseases, chronic respiratory diseases, and cancers, [and] cannot be overlooked. To which genetic and ethnic factors may be added.”
An Incomplete Picture
Islam Hussein, an Egyptian virologist based in the United States, said the picture “is still incomplete”. He said that considering this gene “a single factor responsible for determining the severity of infection is a defective vision of a very complex disease, which we are still trying to decipher.”
“It seems that there is a genetic predisposition for some people or some ethnicities that may contribute to an increased risk of complications when infected with viruses like the ones causing Covid-19, influenza and others.”Mona Kayal
A microbiologist and consultant doctor in viral and bacterial diseases at Prague University Hospital
Hussein added that HIV, the virus that causes AIDS, is “one of the most prominent examples of the role genes play in viral diseases. A small percentage of people (mostly Europeans) have a genetic mutation that makes them insusceptible to HIV infection.”
“The picture is, however, completely different with the coronavirus infection,” he said. “It is not black and white as some might imagine. This is an interesting study that reveals a genetic factor that may play a role in determining the chance of developing serious complications, but of course it does not paint the whole picture.”
Hussein expects future studies to “unveil more genetic factors that control the minute mechanical details of coronavirus infection, which may play more important roles.”
Tannous agreed that more studies of more than one country and a larger number of nationalities are needed.
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He believes that the study should contribute to the development of drugs that can reduce the incidence of complications. New drugs could reduce protein levels when the body is infected with the coronavirus, especially among those groups with high levels of the gene.
“There are currently treatments to stop the viral spread, but this study’s results will help researchers identify … a drug that reduces the ACE2 protein in a way that contributes to stopping the viral attack on the respiratory system.”
To read more about Arab scientists’ response to the Covid-19 pandemic, see the following recent articles from Al-Fanar Media:
- “Oral Covid-19 Drug Shows Promise, but Scientists Want More Data.”
- “Pandemic Has Huge Effect on Qatar’s Medical Research Institutions.”
- “Genetics and Artificial Intelligence Drive Qatar University’s Covid-19 Research.”
- “Across the Arab Region, Covid-19 Has Scrambled Scientists’ Plans.”
See also a collection of all of Al-Fanar Media’s articles on how the pandemic has affected education, culture and the arts across the Arab region.