All siblings in the first generation of the family carry haplotypes bearing the susceptibility associated block HLA-DRB5*01:01:01~HLA-DRB1*15:01:01:01; all the siblings not affected with MS carry a haplotype that includes HLA-B*27:02:01 while the affected subject inherited the alternative haplotype including HLA-B*08:01:01:01. Here, HLA-DRB1 is linked to myeloid sarcoma.