This study assayed the pathogenicity of a deleterious missense NFKB1 variant, c.691 C>T, detected in two brothers (S2/3) and their father (S1) from a German family with variable clinical presentations but a shared history of meningococcal meningitis with sepsis and viral meningitis in the different points of their childhood and adolescence. The gene discussed is NFKB1; the disease is Sepsis.