Myelodysplastic syndrome associated with acquired beta thalassemia: "BTMDS".

Most patients with myelodysplastic syndromes (MDS) have macrocytic or normocytic anemia as a result of ineffective erythropoiesis due to clonal hematopoiesis. Occasional patients with MDS have microcytic red blood cell (RBC) indices in the absence of iron deficiency, however, and a high proportion of such patients have decreased alpha globin expression associated with somatic mutations in the chromatin remodeling factor ATRX; an established alternative mechanism for acquired alpha thalassemia in myeloid neoplasia is clonal deletion of the alpha globin cluster on chromosome 16p. This clinicopathological phenomenon has been called “acquired alpha thalassemia – myelodysplastic syndrome” (ATMDS). Here we describe a patient with new-onset microcytic anemia associated with acquired deletion of the beta globin cluster on chromosome 11, resulting in a beta thalassemia-MDS (BTMDS) phenotype. Phenotype-genotype correlation studies may reveal associations of specific mutation patterns with other recurrent MDS-associated hematological findings.