Some people may be more susceptible to coronavirus because of their genetic make-up, early research suggests, after analysing symptom data from twins.
According to data submitted to a symptom tracking app, genes are 50% responsible for the presentation of key symptoms of Covid-19 including fever, fatigue and loss of taste and smell.
A team of scientists from King's College London looked at information from 2,600 twins on the Covid-19 Symptom Tracker app, including their health, symptoms and level of contact with their co-twin, which helped understand how genes influence the symptoms people exhibit.
"I would like to say a big thank you to all our twins for logging their symptoms and health status regularly in the app," said Professor Frances Williams, from King's College London and TwinsUK.
— TwinsUK research (@TwinsUKres) April 27, 2020
"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."
They noticed that genes were almost 50% responsible for the development of symptoms of delirium, fever, fatigue, shortness of breath, diarrhoea and loss of taste and smell in individuals.
Meanwhile, other symptoms such as hoarse voice, cough, chest pain and abdominal pain were thought to be a result of the surrounding environment.
It is hoped these findings could provide scientists with an indication on how to go about developing treatments, as well as helping to identify high-risk groups.
The research has been published in a pre-print non-peer reviewed paper published online.
Some two million people in the UK have downloaded the Covid-19 Symptom Tracker app, which is helping to inform scientists about the virus's progression, though the number actually using the app fell by almost 75% earlier this month.
However, an analysis of the data published on April 8 suggests coronavirus lockdown is working, with the number of people aged 20-69 who are reporting Covid-19 symptoms falling from 1.9 million to 1.4 million across the UK.
"It's essential that everybody keeps logging their health status in the app – even if you feel well," said Professor Tim Spector from King's College London.
"The data you provide enables us to carry out this urgent research to understand the behaviour and progression of the virus."