Study investigates the role of genetics in rare post-COVID condition

A study has highlighted how rare variants of a gene that regulates the gut lining may increase the risk by up to 4 times of developing multisystem inflammatory syndrome in children (MIS-C).

An international team of researchers, led by Imperial College London and including experts from Evelina London and King's College London, has discovered genetic differences which help to explain why some children with mild COVID-19 develop a severe inflammatory condition called MIS-C (also known as paediatric multisystem inflammatory syndrome, or PIMS-TS).

The condition occurs weeks after the initial COVID-19 infection and can result in the inflammation of organs. Evelina London was one of the first hospitals in the world to report MIS-C as a new condition in April 2020.

In the study, the team looked at the genes of 154 children with MIS-C, including some patients from the paediatric intensive care unit at Evelina London Children's Hospital. They took blood samples to examine patients' genes and developed a technique to search for genetic variants that might be associated with MIS-C.

They found that many of the children had a variant in the BTNL8 gene, which is involved in regulating immune responses in the gut. The children with these rare variations were 4 times more likely to develop inflammation. This may be because the variations make their gut more sensitive to the COVID-19 virus.

Paul Wellman, paediatric intensive care research charge nurse at Evelina London, said:

We are grateful to all the patients and their families who took part in the study. Their invaluable contribution has helped to progress our understanding of MIS-C towards improving patient care in the future.

Professor Ming Lim, Evelina London's research lead, and consultant paediatric neurologist at Evelina London Children's Hospital said: "Ever since we first reported MIS-C in 2020, we have been committed to increasing our knowledge of this serious condition. Understanding its genetic basis provides new insights into how it develops and who is at risk, enabling us to provide better care for children with MIS-C."