Research reveals that multiple genes are associated with severe covid

Reporter : Xu Yue / Publisher : China Science News / http://news.sciencenet.cn/htmlnews/2020/10/446894.shtm / Translation, editing : Gan Yung Chyan, KUCINTA SETIA

Image : A study of severely ill patients with covid (novel coronavirus pneumonia, COVID-19) found that some genes make some people more likely to become severely ill patients. (Fabio Teixeira / Anadolu Agency / Getty Images)

The covid epidemic is still ongoing, and there is a question that has always plagued people: Why some people infected with SARS-CoV-2 have no obvious symptoms while some people have severe symptoms and are even sent to the intensive care unit.

Some previous studies have found that age and previous human health conditions, such as obesity, are the main reasons for this gap. However, geneticists also want to know whether a person's DNA can also explain this difference. Now, they found some tantalizing clues.

According to "Science" reports, a British team that has studied more than 2,200 patients with covid has identified common gene variants associated with severe covid and pointed out existing drugs that can help treat them. Recently, related research was published online on the preprint platform medRxiv.

"This is really exciting. Every gene provides a potential target for treatment." said Priya Duggal, a genetic epidemiologist at Johns Hopkins University in the United States.

Kenneth Baillie of the University of Edinburgh, a intensive care doctor and geneticist, led the new study. "Due to the amazing speed of development of the covid epidemic, even if only a few months of time are saved, many lives can be saved," Baillie said.

The new study confirmed that the region of chromosome 3 is involved in the process of covid, and discovered a gene called IFNAR2, which encodes the cell receptor for interferon. Interferon is a powerful molecular messenger. When a virus invades cells, it can activate the immune system. One in four Europeans has a variant of IFNAR2, which increases the risk of becoming a severely ill patient with covid by 30%.

Baillie said that the IFNAR2 gene is "completely complementary" to the results of a study published in Science last month: The very rare mutation that causes the failure of IFNAR2 and the other 7 interferon genes can be effective in about 4% of severe cases. This explains the situation.

One of the more surprising findings of the new research is the OAS gene, which encodes a protein that activates enzymes that break down viral RNA. Any one of these genetic changes may change this code, which in turn allows the virus to multiply. Research data shows that this mutation, like the above-mentioned interferon genetic risk factors, will have an impact on the progression of covid.

The research team also discovered other genes that enhance the inflammatory response to lung injury caused by the new coronavirus, which may be fatal to some patients. One is DPP9, which encodes an enzyme known to be related to lung diseases; the other is TYK2, which encodes a signal protein related to inflammation. Drugs targeting these two gene proteins are already in use, such as DPP9's diabetes enzyme inhibitor and rheumatoid arthritis treatment baricitinib (a product that blocks TYK2).

Related paper information: https://doi.org/10.1101/2020.09.24.20200048