Hyper-IgM syndrome: a case report.

Hyperimmunoglobulin M syndrome is a rare primary immunodeficiency disorder. We report a case of a 6-month-old boy who suffered from developmental delays, frequent respiratory tract infection, and unusual fungal and bacterial infection. X-linked hyperimmunoglobulin M syndrome was ultimately diagnosed with decreasing immunoglobulin-G, A, and E (immunoglobulin G = 51.3 mg/dL, immunoglobulin A = 8.32 mg/dL, immunoglobulin E <17.5 mg/dL), elevating immunoglobulin M (immunoglobulin M = 140 mg/dL), and decreasing T-cell expression of the CD40 ligand over flow cytometry. Seizure episodes and hypotonia developed with greater signal intensity at the putamen in a brain magnetic resonance imaging, which is compatible with hypoxic ischemic encephalopathy. This is the youngest proven case of hyper-IgM syndrome in Taiwan ever reported.