HLA-DRB1 and myeloid sarcoma: In this study, meta-analysis showed increasing levels of serum 25-(OH) hydroxyvitamin D (based on a vitamin D genetic risk score constructed using 3 single nucleotide polymorphisms associated with vitamin D levels) decreased the odds of pediatric-onset MS (for each additional risk SNP OR = 0.72, 95% CI: 0.55–0.94; P = 0.02) after controlling for sex, genetic ancestry, HLA-DRB1*15, and more than 100 single nucleotide polymorphisms identified as MS-risk variants (16).