Multiple sclerosis spinal cord lesions involve the entire cord but are more frequently observed in cervical than thoracolumbar regions.2,3 Multiple sclerosis-specific lesions in the cord typically span over one to two vertebral segments, but rarely over three or more vertebral segments (a distinguishing feature of neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein antibody-associated disease (Table 1; Supplementary Table 1). This evidence concerns the gene OMG and multiple sclerosis.