This syndrome is genetically characterized by somatic mutation affecting methionine-41 (p.Met41) in UBA1, an X-chromosome gene encoding ubiquitin-like modifier-activating enzyme1, and clinically with inflammatory syndrome and cytopenia, as well as recurrent fevers, pulmonary involvement, neutrophilic dermatoses, cutaneous vasculitis, macrocytic anemia, hematopoietic dysplasia, and bone marrow vacuolization restricted to myeloid and erythroid precursor cells [12]. This evidence concerns the gene UBA1 and macrocytic anemia.