An international team of researchers has found a genetic link to long-term symptoms after COVID-19. The identified gene variant is located close to the FOXP4 gene, which is known to affect lung function. The study, published in Nature Genetics, was led by researchers at Karolinska Institutet in Sweden and the Institute for Molecular Medicine in Finland.

Biological causes behind persistent symptoms after COVID-19 infection, known as long COVID or post-COVID, remain unclear. Common symptoms include fatigue, cognitive difficulties, and breathing problems, which can reduce quality of life.

In an international collaboration —the Long COVID Host Genetics Initiative—researchers have analyzed genetic data from 6,450 long COVID patients and more than a million controls across 24 studies from 16 countries.