UBA1 and myelodysplastic syndrome: It predominantly affects older men, as UBA1 escapes X-chromosome inactivation.7 A subset of patients with VEXAS present with myelodysplastic syndrome (MDS) or plasma cell neoplasms, typically with low-risk features.8,9 Somatic mutations in non-UBA1 genes can coexist with the canonical UBA1 mutations, but they usually display a spectrum of age-related clonal hematopoiesis rather than direct disease pathology.8–10