The COVID-19, caused by the new coronavirus pandemic, it is strange and tragically selective. Only some infected people become ill, and although the most severely ill patients are elderly or have complicated problems such as heart disease, some of those who die by the disease are previously healthy and even relatively young people. The researchers are preparing now to track the genomes of the patients for variations in DNA that explain this mystery. The findings could be used to identify those most at risk of developing a serious disease and that they may be protected, and also could guide the search for new treatments, according to a magazine article Science signed by Jocelyn Kaiser.
The projects range from ongoing studies with DNA to many thousands of participants, some of which are infecting now with the coronavirus, until new efforts that are collecting DNA from patients with COVID-19 in places highly affected Italy. The objective is to compare the DNA of people who have severe cases of COVID-19 (that means disease coronavirus 2019) -but no underlying disease such as diabetes, heart or lung disease – with those who have a mild disease or no disease. “We see huge differences in the clinical outcomes between and within countries. How much of this is explained by the genetic susceptibility is a very open”, says the geneticist Andrea Ganna Institute of Molecular Medicine, University of Helsinki, Finland (FIMM).
It is difficult to predict what will come out of these witch hunts of genes, say some researchers. But there are suspects obvious, such as the gene that encodes angiotensin converting enzyme 2, the cell surface protein (ACE2), the coronavirus uses to enter the cells of the respiratory tract. Variations in the gene ACE2, which alter the receptor may facilitate or hinder the entry of the virus into the cells, says immunologist Philip Murphy of the National Institute of Allergy and Infectious Diseases, whose laboratory identified a mutation is relatively common in another protein of the human cell surface, the CCR5, which makes some people highly resistant to HIV.
Ganna is leading an important effort to gather genetic data from the patients of COVID-19 from all over the world. The idea emerged quite spontaneously” about two weeks ago, when “the whole world was sitting in front of their computers watching this crisis”, said Ganna, who is also affiliated with the Broad Institute, a power plant genomics in the united States.
He and the director of FIMM, Mark Daly, created quickly a website for your project, the Initiative for Genetics of Host COVID-19, and is put in contact with colleagues that perform large studies of biobanks that follow thousands of volunteers over the years to find links between DNA and health. At least a dozen of biobanks, the majority of them in Europe and the united States, have expressed their interest in providing the data COVID-19 participants who agreed with this. Among them are FinnGen, which has DNA samples and data on the health of the 5% of the 5 million people of the Finnish population, and the biobank of 50,000 participants of the School of Medicine Icahn Mount Sinai.
The UK Biobank, one of the biobanks of the world’s largest with DNA data to 500.000 participants, also plans to add the health data of the participants of COVID-19 to your data set. And the icelandic company deCODE Genetics, which is helping to test a large part of the population of the nation to see who is infected with the new coronavirus, has received permission from the government to add these data and any later symptom of COVID-19 to your database, which contains information about the genome and the health of half of the 364.000 inhabitants of Iceland, says its ceo Kári Stefánsson. “We will do everything possible to contribute to resolve this,” says Stefánsson.
Another effort to identify the variant DNA protective or susceptible is the Personal Genome Project run by George Church of Harvard University, which recruits people who are willing to share their entire genome, tissue samples and health data for research. Earlier this month sent out questionnaires to its thousands of participants, asking about the state of COVID-19. More than 600 in the united States responded in 48 hours. “It seems that most of the people want to do their part,” says Church, whose group is not yet part of the collaboration of Ganna.
Other researchers working with the initiative of Ganna are recruiting patients COVID-19 directly within the hospitals for such genomic studies. The geneticist Italian Alessandra Renieri University of Siena is expected that at least 11 hospitals in the nation to give their ethical approval for your team to collect DNA samples from patients willing. “In my opinion, the genetic differences [del huésped] are a key factor… for the susceptibility to acute pneumonia severe”, says Renieri.
The researcher of pediatrics Jean-Laurent Casanova of the Rockefeller University, which specializes in the identification of rare genes that can make that healthy young people are susceptible to certain serious diseases, is resorting to a network of paediatricians from all over the world to find the relatively few young people who develop COVID-19 serious enough to be admitted to intensive care. “We studied only patients who were previously healthy and under the age of 50 years, as it is more likely that his severe illness by COVID-19 has a genetic basis, ” he explains.
In addition to the genetic variants of the ACE2 receptor, the scientists want to see if the differences in the genes of the human leukocyte antigen, which influence the immune system’s response to viruses and bacteria, affect the severity of the disease. And some researchers want to do a follow-up of a finding, that a chinese team reported in a prepress: people with blood type O may be protected from the virus. “We’re trying to figure out if those findings are solid”, says the geneticist, human of the University of Stanford, Manuel Rivas, who is contributing to the initiative of Ganna.
The catastrophic spread of the coronavirus should increase soon the number of patients with COVID-19 available for these hunts genes. And that could speed up the findings. Ganna expected that the first susceptibility genes to be identified in a couple of months.