Researchers in Taiwan have discovered a new mutation in the Omicron subvariant BA.2.3.7 that might cause severe neurological complications in children.
A study published in the International Journal of Infectious Diseases included the medical records and clinical samples of five patients aged 1 to 5 years who were admitted to Tri-Service General Hospital in Taiwan in May 2022. They were all suspected of having meningoencephalitis.
All patients developed severe neurological symptoms such as seizures within 1 to 2 days after the onset of respiratory symptoms and fever.
None of the patients’ cerebrospinal fluid samples tested positive for COVID-19; however, the genome sequencing revealed that sequences of viruses belonged to the Omicron lineage BA.2.3.7. Moreover, the sequences had previously unidentified K97E mutation in the S protein that differed from other BA.2.3.7 lineage strains.
Researchers say these severe neurological symptoms might be related to hyperimmune states triggered by the mutation.
“K97E mutation, which has not been observed in Taiwan previously, potentially explains the sudden increase in incidence of severe neurological symptoms in pediatric patients due to its possible effect on immune regulation,” the researchers conclude.
One of the patients died of acute cerebral edema with brain stem compression and multiple organ failure, while others fully recovered and were discharged after a 4-9 days stay in the hospital.
An earlier wide-ranging observational study from Oxford University found that children were twice as likely to develop epilepsy or seizures within two years of a COVID-19 infection compared to other respiratory diseases.
However, the study only included children with a diagnosis of COVID-19 or another respiratory infection in the medical record and thus would have missed those who never sought care.
International Journal of Infectious Diseases. Critical pediatric neurological illness associated with COVID-19 (Omicron BA.2.3.7 variant) infection in Taiwan: Immunological assessment and viral genome analysis in tertiary medical center.