Of these, we excluded 8 (16%) cases, 3 because of insufficient information and 5 because of alternative diagnoses (1 each of GBS and Zika virus–reactive IgM in CSF, neurosurgery-associated bacterial meningitis, multiple sclerosis preceding vaccination and postvaccination demyelination, mononucleosis-like syndrome with acute toxoplasmosis, and meningoencephalitis with a positive rapid test result for dengue virus [DENV]). The gene discussed is CD40LG; the disease is bacterial meningitis.