One of the biggest puzzles of the Pandemic has been why the majority of people infected with coronavirus have no symptoms whatsoever, whilst others become gravely ill and die. A study in Nature of more than 2,200 intensive care patients has identified specific genes that may hold the answer. They make some people more susceptible to severe Covid-19 symptoms. The findings shed light on where the immune system goes wrong, which could help identify new treatments.
These will continue to be needed even though vaccines are being developed, says Dr Kenneth Baillie, a consultant in medicine at the Royal Infirmary in Edinburgh, who led the Genomicc project. “Vaccines should drastically decrease the numbers of covid cases, but it’s likely doctors will still be treating the disease in intensive care for a number of years around the world, so there is an urgent need to find new treatments.”
Scientists looked at the DNA of patients in more than 200 intensive care units in UK hospitals. They scanned each person’s genes, which contain the instructions for every biological process – including how to fight a virus. Their genomes were then compared with the DNA of healthy people to pinpoint any genetic differences, and a number were found – the first in a gene called TYK2. “It is part of the system that makes your immune cells more angry, and more inflammatory,” explained Dr Baillie. But if the gene is faulty, this immune response can go into overdrive, putting patients at risk of damaging lung inflammation.
But the genome still holds some mysteries. The Genomic study – and several others – has revealed a cluster of genes on chromosome 3 strongly linked to severe symptoms. However, the biology underpinning this is not yet understood. More patients will now be asked to take part in this research. click full source
Right at the start of the pandemic, I always thought there had to be some genetic reason why most people were unaffected and others became so ill, particularly the elderly with comorbidities and poor immune systems. Now we know, but there is a long way to go in fully understanding the reasons why.