UBA1 and VEXAS syndrome: The syndrome is a combined hematological and rheumatological condition caused by a somatic mutation in the UBA1. There is an association between VEXAS and hematological conditions such as myelodysplastic syndrome (MDS), monoclonal gammopathies of uncertain conditions (MGUS), multiple myeloma (MM), and monoclonal B-cell lymphoproliferative conditions.