In addition, we studied the linkage of HLA-DRB1 and HLA-DQB1 allele polymorphisms and HLA-DRB1 ~ HLA-DQB1 haplotypes with different clinical features of MS, such as optic neuritis, sensory impairment, and brainstem symptoms in Jordanian MS patients. This evidence concerns the gene HLA-DRB1 and optic neuritis.