Most points were scored in the categories “Antibiotic prescriptions,” “RTIs,” and “Visits to the GP,” while points were rarely scored for “Other infections” (e.g., meningitis, osteomyelitis; Table S1) and “Auto-immune symptoms.” There were no previously registered reduced immunoglobulin levels in the EHRs of included patients, most likely because these were not requested by GPs: total IgG and IgM were determined in only one patient, and IgG subclasses in none. Here, CD40LG is linked to meningitis.