Atypical Optic Neuritis includes entities in the demyelination diseases’ spectrum such as ON associated with neuromyelitis optica spectrum disorder (NMOSD), which is associated with aquaporin 4 antibodies (AQP4), and myelin oligodendrocyte glycoprotein antibody disease (MOGAD), which is associated with myelin oligodendrocyte glycoprotein (MOG) antibodies. This evidence concerns the gene AQP4 and demyelinating disease.