RESUMO
<p><b>OBJECTIVE</b>To study the clinical features of myelodysplastic syndromes (MDS) patients with t (1; 3) (p36; q21) and the expression of the involved genes.</p><p><b>METHODS</b>4 cases of MDS with t (1; 3) (p36; q21) were reported. The expression level of two transcription forms (PR-containing form MEL1 and PR-lacking form MEL1s) of MEL1 gene in normal fetus tissues, 2 healthy donor bone marrows and bone marrows from 3 MDS patients with t (1; 3) (p36; q21) were detected by semiquantitative reverse transcription polymerase chain reaction (RT-PCR).</p><p><b>RESULTS</b>MDS patients with t (1; 3) (p36; q21) mainly presented with debility. Hemogram was macrocytic anemia, normal or elevated white blood cell and platelet counts. The bone marrow showed tri-lineage dysplasia especially dysmegakaryocytopoiesis. The patients had poor prognosis. MEL1 form was mainly expressed in the normal fetus tissues and healthy bone marrows, while the bone marrow cells from MDS patients with t (1; 3) (p36; q21) mainly or only expressed MEL1s.</p><p><b>CONCLUSIONS</b>MDS patients with t (1; 3) (p36; q21) may be a new unique entity. Overexpression of MEL1s induced by t (1; 3) (p36; q21) might play an important role in the pathogenesis of this entity.</p>