In southern Japan, MS patients with HLA-DRB1*04:05 were younger at disease onset (p = 0.009) with higher visual FS scores (p = 0.003) and tended to have optic nerve involvement (optic neuritis) more frequently than patients without DRB1*04:05 (p = 0.090). The gene discussed is HLA-DRB1; the disease is optic neuritis.