IFNA21 and COVID-19: Furthermore, 6 of the 14 patients with MIS-C with truncating variants harbored 2 such variants in 2 different genes (Figure 3B and Table), including 2 patients (COVGEN-7 and COVGEN-36) who were double heterozygous for truncating variants in IL22RA2 and IFI44L and 1 patient (COVGEN-30) with 2 heterozygous variants in IFNA6 and IFNA21. Similar findings were obtained when analysis was focused only on patients with MIS-C who tested positive for SARS-CoV-2 (n = 36) and excluding those with only exposure to COVID-19 (eFigure 2 in the Supplement).