X-linked hyper-IgM syndrome presenting as severe Pneumocystis pneumonia in a 6-month-old infant: a case report
BackgroundX-linked hyper-immunoglobulin M (XHIGM) syndrome is a rare primary immunodeficiency caused by mutations in the CD40 ligand gene (CD40LG), characterized by defective T-cell-dependent B-cell class-switch recombination. Patients typically presen…