A fluorescence <i>in situ</i> hybridization analysis detected <i>PML-RARA</i> fusion genes in the patient's bone marrow specimens, leading to the diagnosis of acute promyelocytic leukemia.<h4>Conclusion</h4>A del(5q) is one of the characteristic chromosomal abnormalities observed in myelodysplastic syndrome. The gene discussed is RARA; the disease is acute promyelocytic leukemia.