The extent to which Covid-19 patients suffer from the virus is largely governed by their genes, according to research.

The finding could help medics to identify people most at-risk from Covid-19 and scientists develop treatments.

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Researchers from King’s College London have found that almost 50 per cent of the symptoms people experience with Covid-19 are connected to their genetic make-up.

These genes are responsible for symptoms such as delirium, fever, fatigue, shortness of breath, diarrhoea and loss of taste and smell, according to the latest health data, collected from more than 2.7 million app users.

Non-genetic factors

Meanwhile, underlying health factors, such as lifestyle, obesity, diabetes or high blood pressure, are responsible for the development of other symptoms such as a hoarse voice, cough, chest and abdominal pain, the researchers said.

The researchers are unclear whether people with beneficial genes are less likely to catch the disease in the first place – or just less likely to have severe symptoms when they do.

The study included 2,600 twins – some identical and some not. The researchers found a greater similarity between the identical twins – who share all of their genes – and non-identical twins, who share only half.

This enabled them to conclude that genes play a key role in coronavirus symptoms.

The app

The King’s College app is available at https://covid/joinzoe.com/ and participants are being asked to record information about their temperature, tiredness levels and symptoms associated with Covid-19.

Professor Tim Spector from King’s College London said: “It’s essential that everybody keeps logging their health status in the app – even if you feel well. The data you provide enables us to carry out this urgent research to understand the behaviour and progression of the virus.”

Professor Frances Williams from King’s College London said: “I would like to say a big thank you to all our twins for logging their symptoms and health status regularly in the app. It’s because of their tremendous commitment to health research over the years that we are able to carry out this crucial research so quickly.”