Most people infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are asymptomatic or only show minor illness. Hypoxemic pneumonia results from the infection in roughly 10% of cases, which is far more uncommon in children. When coronavirus disease 2019 (COVID-19) problems were discovered in 31 young children with preexisting inborn errors of immunity (IEI) but no molecular diagnosis, researchers investigated them for a study. The patients ranged in age from 0.5 to 19 years.

All patients underwent whole-exome sequencing for genetic assessment. They examined plasma levels of SARS-CoV-2-specific antibodies, autoantibodies against type I IFN (IFN-I), and inflammatory components. Additionally, they looked at reported IEI patients’ COVID-19 illness severity and outcomes.

In 28 individuals (90.3%), mutations that might impact IFN signaling, T- and B-cell activity, the inflammasome, and the complement system were shown to be probable genetic causes of IEI. Of the patients examined, 65.5% had virus-specific antibodies that could be detected, and 6.8% had IFN-I autoantibodies. The diagnostic criteria for multisystem inflammatory syndrome in children were met by five cases (16.1%). 11 patients (35.4%) passed away due to COVID-19 issues. In all, 381 IEI kids with COVID-19 have been documented in the literature as of this writing. Although it’s possible that many people with asymptomatic or moderate illness were unreported, severe COVID-19 manifestation was seen in 23.6% of recorded cases, and the fatality rate was 8.7%.

When infected with SARS-CoV-2, young patients with preexisting IEI may have increased mortality than kids without IEI. Understanding the genetic underpinnings of IEI patients with severe/critical COVID-19 illness may aid in the development of new preventative and therapeutic approaches for the disease and its consequences in young children.