Environmental and genetic risk factors in the development of neuromyelitis optica

Introduction: Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease mainly characterized by the optic nerve and spinal cord involvement. The mentioned disorder has peculiar characteristics as it is a kind of astrocytopathy and the antibody against water channels plays a major role in its pathogenesis. Areas covered: This review covers the different genetic and environmental risk factors for NMOSD. The disease has a wide diversity in terms of lesions, symptoms, age of involvement, and presence of anti-aquaporin 4 antibody (Anti-AQ4). NMOSD has been classified into two types of seropositive and seronegative depending on the presence or absence of Anti-AQ4. As a result, this study reviews various genetic and environmental risk factors of NMOSD according to Anti-AQ4 status. Expert opinion: This review indicated that NMOSD disease has its specific risk factors. These risk factors may include vitamin D insufficiency, smoking, infections, and dietary habits. Another very important issue reported in these studies was the diversity of risk factors, whether genetic or environmental, in seropositive and seronegative patients. Identification of the risk factors and their modification can help reduce the risk of NMOSD.