Genetic testing was nondiagnostic in thirteen children: suspected MSMD (2), hyper-IgE syndrome (2), severe congenital neutropenia (2), hemophagocytic lymphohistiocytosis (1), hyper-IgM (1), chronic granulomatous disease (1), combined immunodeficiency (1), unclassified immune dysregulation (1), C1q deficiency (1), and IL17 pathway defect (1). Here, CD40LG is linked to Mendelian susceptibility to mycobacterial diseases.