Genetic Susceptibility to COVID-19: What We Know So Far – Healthline

The novel coronavirus SARS-CoV-2, which causes COVID-19, has caused millions of infections worldwide. As time has passed, it has become increasingly clear that COVID-19 is not a cookie-cutter disease.

People vary significantly in their susceptibility to infection, symptoms, and disease severity. Certain risk factors clearly play a role. Could genetics also play a part?

Researchers are examining the role of genetics in peoples reactions to the virus. While far from conclusive, data indicates that some of your genes may influence how SARS-CoV-2 affects your health.

Read on to learn what research has uncovered.

To look for genes that may influence the impact of COVID-19, geneticists scan the DNA of large study groups. This helps them find and identify connections between specific DNA sequences and disease characteristics.

Early genetic studies have uncovered compelling clues that certain genomic variants and blood types may play a role in how people react to the SARS-CoV-2 virus.

Angiotensin-converting enzyme 2 (ACE2) receptors are proteins found on the surface of certain cells. ACE2 receptors generate other proteins that regulate cell function. ACE2 receptors also allow the SARS-CoV-2 virus to enter your cells.

ACE2 receptors are located in the lungs, blood vessels, kidneys, and other parts of the body. They help regulate blood pressure, wound healing, and inflammation.

Everyone has ACE2 receptors, but their amount and locations vary. Multiple studies, including a 2021 study reported in the European Journal of Medical Research, found a link between ACE2 levels and vulnerability to COVID-19.

The same study also found that people with a specific type of genetic variation in ACE2 are at higher risk of SARS-CoV-2 infection. Another finding was a heightened susceptibility to SARS-CoV-2 infection in men compared to women.

Cytokines are proteins released by cells. Cytokines help cells communicate with each other. They also work to regulate inflammation and the bodys immune response to infection.

A cytokine storm is an overreaction of the immune system to infection from an invading host, such as SARS-CoV-2. During a cytokine storm, your cells release too many cytokines. This causes high levels of inflammation and the overactivation of certain immune cells.

The results of a cytokine storm can be severe and include tissue damage, organ failure, and sometimes death.

A review of multiple studies found that several genetic variants in cytokine genes may be related to cytokine storm and disease severity. Studies also found that these variants might be related to COVID-19 complications, including venous thrombosis.

A large study analyzed genes found along a stretch of chromosome 3. The study found compelling information about specific genes and their potential impact on respiratory failure caused by COVID-19.

Researchers identified a gene cluster on chromosome 3 linked to susceptibility to respiratory failure in COVID-19 patients. According to researchers, the gene cluster confirmed that ABO blood type played a role, indicating a higher risk for respiratory failure from COVID-19 for people with type A blood.

The HLA gene helps regulate your bodys immune response. Decades of research have found that people with certain HLA alleles (slight gene mutations, or variations) are prone to various autoimmune, inflammatory, and malignant diseases. Scientists call this phenomenon HLA disease association.

A 2021 review found that people with certain HLA alleles were more vulnerable to COVID-19 and severe illness than the general population.

If you were assigned male at birth, you might be at higher risk for serious illness from COVID-19. While some data points to lifestyle factors more common in men (such as smoking or drinking alcohol), genetic factors are also at play.

Men tend to express higher amounts of ACE2, making them more susceptible to COVID-19. A 2021 study suggests that this alone doesnt account for the difference in response.

The study also highlights genes present in men that might make them more prone to infection and genes present in women that may help them fight off infection.

There are also genes on the X-chromosome that influence your immune response. There are about 55 times as many of these genes on the X-chromosome as on the Y-chromosome.

As men only have one copy of the X-chromosome, variants in genes on this chromosome may have a greater effect on how COVID-19 progresses.

Its also important to remember that genetic traits are sometimes clustered among people with the same nationality, ethnicity, or culture. This can skew study results, especially in places where poor living conditions or poverty are factors.

Still, three 2021 studies (1, 2, 3) state that we cant ignore ethnic differences in COVID-19 susceptibility. Some genes that influence the course of COVID-19, such as HLA alleles, are more prevalent in certain ethnicities.

Another study noted that Black people tend to have more variations in the genes that affect ACE2.

Again, more research is needed before we fully understand the true impact.

COVID-19 is known to present with a wide variety of symptoms. While some symptoms are common, the virus tends to affect people in many different ways. Your genetics may play a role here too.

A 2021 study linked COVID-19 with altered gene expression in specific tissues or cells. This suggests that certain genetic variations may make you more likely to experience certain symptoms.

The study also noted that some of the genes they studied were also linked to ethnicity. This means that some symptoms may be more common in certain ethnic groups.

Researchers and geneticists are sharing their findings on genetics and COVID-19 through the COVID-19 Host Genetics Initiative.

As more studies take place, the biological pathways that affect your susceptibility or natural immunity to this disease may become more apparent.

This research may help generate new types of drugs that can treat COVID-19. It may also help determine why some people have a severe reaction to infection, and others experience mild to no symptoms.

While exciting and compelling, its important to remember that the research on genetics and COVID-19 is still new. We need more research before we can fully understand the impact of genes on this disease.

Knowing your risk factors can help you make decisions concerning exposure to the virus. Risk factors for COVID-19 and severe symptoms include:

No gene makes you fully immune to COVID-19. No matter what your own risk may be, these measures can help protect you from infection:

A growing body of evidence has linked certain genes and gene mutations to COVID-19 susceptibility. While compelling, this information is still new. We need more research to fully understand how our genes affect our response to the coronavirus.

As this body of science grows, it may better inform us on how to treat or even prevent COVID-19.

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Genetic Susceptibility to COVID-19: What We Know So Far - Healthline