The finding that HLA-DRB1*15:01 increased the involvement of the optic nerve (optic neuritis) and cerebellum and worsened visual and pyramidal FS scores, resulting in greater PI, is a new finding in Asians and is compatible with several reports in Caucasians showing that DRB1*15:01 is associated with greater MSSS and more severe cognitive impairment18,20. Here, HLA-DRB1 is linked to optic neuritis.