Gene linked to Long Covid found, DNA of thousands of patients sifted

2023-07-12 20:56:33

A team of scientists sifted through the DNA of thousands of patients and found a gene believed to be linked to Long Covid. This is the first hunt for genetic risk factors for post virus syndrome and has produced a success, according to researchers in ‘Nature’ online. The operation could pave the way for larger studies. Meanwhile, the attention of the authors of the work – released in a preprint version – was focused on a DNA sequence close to a gene called ‘Foxp4’, which is active in the lungs and in some immune cells. The analysis involved data collected from 6,450 people affected by Long Covid in 16 countries.

The researchers hope this is just the beginning: a vast amount of data is needed to unravel a complex disorder like this, which has been associated with more than 200 symptoms, including severe fatigue, nerve pain and difficulty concentrating. and memory. “It’s very important that studies like this get done,” says Chris Ponting, who studies medical bioinformatics at the University of Edinburgh in the UK.

They are “first steps” in learning more about the causes of Long Covid, says Stéphanie Longet, an immunologist at the Jean Monnet University in Saint-Étienne, France, who has experienced this syndrome on her skin. How did we come to identify what appears to be a susceptibility gene? For more than three years, the global Covid-19 initiative Host Genetics has been looking for DNA sequences associated with the risk of developing a severe form of Covid. That hunt, which is underway, has targeted genes involved in the immune system and in allowing the Sars-CoV-2 virus to enter cells.

The Long Covid study is a spinoff from that effort, says Hugo Zeberg, a geneticist at Karolinska Institutet in Stockholm and lead author of the preprint. To study the condition, the team compiled data from 24 studies involving a total of nearly 6,500 people diagnosed with long-term Covid, plus more than a million other participants who played the role of controls. In an analysis that combined data from 11 of these studies, the researchers found a particular region of the genome associated with approximately 1.6 times higher odds of developing Long Covid. That segment of DNA is close to a gene called Foxp4, which is active in the lungs and other organs. The Long Covid-linked variant is also associated with increased expression of Foxp4 in lung cells. And previous research had linked the same gene to an increased risk of severe Covid. But, Zeberg notes, “this variant has a much stronger impact on Long Covid than its impact on gravity.”