Study of clonality in myelodysplastic syndromes: detection of trisomy 8 in bone marrow cell smears by fluorescence in situ hybridization.

The lineage involvement in myelodysplastic syndromes (MDS) is still unclear. To determine the clonality and the evolution of the disorder, a retrospective study on bone marrow smears from seven MDS patients with trisomy 8 was performed using fluorescence in situ hybridization (FISH). We observed that the trisomy of chromosome 8 was selectively expressed in the myeloid-derived cells. No mature lymphocytes or plasma cells expressed three signals. Our studies demonstrate here the value of FISH for identifying the affected cell lineage. Furthermore, the easy quantification of the abnormal cells can help in assessing the progression of the disease.