MOG and demyelinating disease: Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a group of central nervous system (CNS) demyelinating diseases caused by autoantibodies against myelin oligosaccharide protein (MOG), a myelin sheath component protein, and present with a variety of symptoms, including optic neuritis, myelitis, acute disseminated encephalomyelitis (ADEM), brainstem encephalitis, and corticobasal encephalitis.