CSF3 and immunodeficiency disease: G-CSF is a polyfunctional cytokine that influences survival, proliferation, and differentiation of hematopoietic stem cells, and has immunomodulatory effects on the innate and adaptive immune systems.<h4>Objective</h4>To report a case of neuromyelitis optica spectrum disorder (NMOSD) with comorbid immunodeficiency and frequent infections.<h4>Methods</h4>Case report and review of literature.<h4>Results</h4>A 23 years-old man presented with a focal onset seizure with impaired awareness at age 12.