Clinical and biological characteristics of myelodysplastic syndromes with nulisomy Y by fish.

BACKGROUND AND OBJECTIVE In the present study we analyzed the incidence of nulisomy Y by fluorescence in situ hybridization in a group of 24 males diagnosed with myelodysplastic syndromes (MDS). We explored the relationship between this chromosome abnormality and other clinical and biological disease characteristics. METHODS Loss of chromosome Y was present in 7 out of the 24 males analyzed (29%); the number of cells carrying this chromosome aberration ranged between 19% and 90%. From the clinicobiological point of view, the group of patients with nulisomy Y showed a higher incidence of RA and RAS FAB subtypes (p = 0.04), a lower WBC count (p = 0.04), a lower proportion of blast cells both in PB (p = 0.009) and BM (p = 0.06) associated with a decreased myeloid/erythroid ratio (p = 0.01). RESULTS No clear association was detected between loss of chromosome Y and other numerical chromosome abnormalities involving chromosomes 7 and 8. In contrast, 2 out of the 7 cases with loss of chromosome Y also displayed monosomy 1 by FISH. However, the use of appropriate dual stainings showed that these two abnormalities were present in different cell populations (that is, they never coexisted in the same cell population), which supports the notion of the existence of clonal heterogeneity in MDS patients. INTERPRETATION AND CONCLUSIONS From the prognostic point of view, MDS patients with loss of chromosome Y displayed a higher survival rate, although these differences did not reach statistical significance.