HDAC9 and myeloid sarcoma: Whole group associations of HDAC9 (+0.05 points/year, 95%CI: 0.01–0.10, P = 0.010) and EVI5 (+0.05 points/year, 95%CI: 0.01–0.10, P = 0.03) with annualized change in EDSS were not replicated in MS-only analyses, suggesting over-representation of negative genotypes for both genes within the CIS cohort.