What Will Your COVID-19 Symptoms Be? Your Genes May Hold the Answer

The symptoms of COVID-19 have are heavily influenced by genetics, according to a preprint article from researchers at King’s College London.

The study looked at data from the COVID-19 Symptom Tracker app, in which users report their health on a daily basis. Researchers used machine learning algorithms to identify the combinations of symptoms that are indicative of a person having COVID-19. Among those using the app were 2633 members of the TwinsUK study. This allowed the researchers to identify those twins who were likely to have contracted the disease based on their symptom reporting, in an attempt to establish the genetic influence on COVID symptoms.

The idea was to look at the similarities in symptoms or non-symptoms between the identical twins, who share 100% of their genes, and the non-identical twins, who only share half of their genes. If there is a genetic factor in expressing the symptoms then we’d see a greater similarity in the identical [twins] than the non-identical [twins], and that is what we showed.

Professor Tim Spector
Davis, N. (2020). Study of twins reveals genetic effect on Covid-19 symptoms. Retrieved 29 April 2020, from https://www.theguardian.com/world/2020/apr/27/study-of-twins-reveals-genetic-effect-on-covid-19-symptoms

Loss of taste and smell, fever and diarrhoea were particularly strongly associated with genetics, while coughing, loss of appetite, and chest and abdominal pain were not. Overall, roughly 50% of the disparity between people’s symptoms appeared to be due to genetic factors.

It is not yet clear what these genetic factors are, but one possibility would be variations in the ACEII receptor – the target that the Sars-CoV-2 spike protein binds to before the virus enters a human cell. The researchers have suggested that genes affecting the immune system and the gut microbiome could also play an important role. Further study of the genetic factors affecting COVID-19 symptoms could prove useful for predicting who will be most at risk from the illness, as well as helping other scientists to develop drugs against the virus.