The presence of autoantibodies against myelin oligodendrocyte glycoprotein (MOG) is considered a hallmark of MOG antibody-associated disease (MOGAD), a recently defined demyelinating disease (8, 9) that presents with core clinical features such as optic neuritis, myelitis, and acute disseminated encephalomyelitis (8). The gene discussed is MOG; the disease is demyelinating disease.