The most frequent main genetic causes of cellular and humoral immunodeficiencies in children infected with SARS-CoV-2 were DOCK8 deficiency (n = 6) [62, 125], IL2RG (n = 5) [46, 65, 108, 126], RelB deficiency (n = 3) [91, 92], JAK3 deficiency (n = 3) [31, 46, 131], and IL7Ra deficiency (n = 3) [19, 69, 73]. The gene discussed is RELB; the disease is immune system disorder.