After correction for multiple comparisons, one adult-onset MS gene (PRF1, p = 2.70 × 10−3) and two MHC genes (BRD2, p= 5.89 × 10−5 and AGER, p= 7.96 × 10−5) were significantly associated with POMS. This evidence concerns the gene PRF1 and myeloid sarcoma.