Neuromyelitis optica spectrum disorders (NMOSD) are autoimmune diseases of thecentral nervous system (CNS) that mainly affect the optic nerve and the spinal cord.In the majority of cases, the pathology depends on the damage of astrocytes mediatedby an auto-antibody to aquaporin-4 (AQP-4). This evidence concerns the gene AQP4 and neuromyelitis optica.