SCIENTISTS have pinpointed genetic variants which put patients at increased risk of severe Covid.

The Edinburgh University-led study, the largest of its kind in the world, found that variations in genes controlling the levels of a key protein - known as Factor Eight - which is involved in blood clotting were associated with critical illness among Covid patients.

Researchers believe this may explain some of the clotting abnormalities seen in severe cases of Covid-19.

The study also found that a single gene variant which disrupts a key messenger molecule in immune system signalling – called interferon alpha-10 – was enough to increase a patient’s risk of severe disease.

This suggests that treating patients with interferon – proteins released by immune cells to defend against viruses – could help to manage disease in the early stages.

The findings, published in the journal Nature, were among a total of 16 new genetic variants linked to severe Covid disease.

It follows an analysis involving more than 57,000 people.

Researchers from the GenOMICC consortium – a global collaboration to study genetics in critical illness - sequenced the genomes of 7,491 patients from 224 intensive care units in the UK and compared them against the genomes of some 48,000 people who did not have Covid-19 or around 1,600 patients with a mild form of the disease.

The work, led by Edinburgh University in collaboration with Genomics England, is expected to pave the way to potential new therapies and diagnostics.

Professor Kenneth Baillie, the project’s chief investigator and a consultant in critical care medicine at Edinburgh University, said: “These results explain why some people develop life-threatening Covid-19, while others get no symptoms at all.

"But more importantly, this gives us a deep understanding of the process of disease and is a big step forward in finding more effective treatments.

“It is now true to say that we understand the mechanisms of Covid better than the other syndromes we treat in intensive care in normal times – sepsis, flu, and other forms of critical illness. Covid-19 is showing us the way to tackle those problems in the future.”

GenOMICC (Genetics of Susceptibility and Mortality in Critical Care) started in 2015 as an open, global consortium of intensive care clinicians dedicated to understanding genetic factors influencing outcomes in intensive care from diseases such as SARS, flu and sepsis.

Led by Edinburgh University, it has been focused since 2020 on Covid-19 research.

Co-author Professor Sir Mark Caulfield, a former chief scientist at Genomics England, said: “As Covid-19 evolves, we need to focus on reducing the number of people getting seriously ill and being hospitalised.

"Through our whole genome sequencing research, we’ve discovered novel gene variants that predispose people to severe illness – which now offer a route to new tests and treatments, to help protect the public and the NHS from this virus.”

It comes as figures show that the number of people in hospital with Covid in Scotland has climbed steadily since mid-February, from a low of 868 on February 13 to 1,360 now. The number of patients in intensive care remains low, at 18.

Dr Rich Scott, chief medical officer at Genomics England, said: "This study illustrates the value of whole genome sequencing to detect rare and common variants that influence critical illness requiring intensive care.

"It represents a major leap forward in our understanding of how our genetic makeup influences severe illness with Covid-19.

“All those involved in the study went to great efforts to engage with all communities within the UK – including groups that have historically been under-represented in medical studies.

"The inclusive element of our work has generated meaningful results for everyone in the country.”