1 Molecular and cytogenetic abnormalities in acute myeloid leukaemia and myelodysplastic syndromes

Abstract

With the use of molecular techniques it is now possible to define even subtle chromosomal abnormalities and the fusion products resulting from translocations. Defined clinical correlations can now be made and prognostic implications are already found. For instance, patients with AML carrying t(8;21), t(15;17) or inv(16) have a better prognosis for long-term survival. This is also illustrated by Figure 1, which shows data of the Dutch HOVON AML study. The definition of patients with a bad or good prognosis has already resulted in the adjustment of treatment protocols. In the near future, with the use of more defined molecular techniques, we might be able to characterize the chromosomal abnormality of each patient, to individualize his treatment and to recognize very early relapses.

Clinical importance of interphase cytogenetics detecting occult chromosome lesions in myelodysplastic syndromes with normal karyotype

“…FISH analysis in particular has increased our ability to detect cytogenetic abnormalities using specific DNA probes to identify each of the chromosomes individually. 9 In comparison with conventional cytogenetics, FISH analysis does not depend on cell division and can be performed on interphase nuclei giving the possibility to examine a larger number of cells. The lower threshold of detection allows for the identification of small clones of abnormal cells which, although missed by conven- …”

“…9 The goals of this study were: (1) to evaluate by interphase FISH analysis the prevalence of the most frequent cytogenetic abnormalities in a group of MDS patients with normal karyotype; (2) to evaluate, in this subset of MDS patients, the clinical and prognostic significance of the presence of FISH abnormalities.…”

Primary acquired sideroblastic anemia, thrombocytosis, and trisomy 8

“…Additional chromosome 8 (trisomy 8) is described in association with both acute nonlymphoblastic leukemia and myelodysplastic syndromes [7,8]. There is no exclusive association with any specific FAB group either in acute non-lymphoblastic leukemia or in the myelodysplastic syndromes.…”

Fluorescence in situ Hybridization Reveals Closely Correlated Results in Cytological and Histological Specimens of Hematological Neoplasias Compared to Conventional Cytogenetics

“…Briefly, slides were pretreated with pepsin solution for 3 min, washed for 1 min in distilled water (dH 2 O), followed by fixation for 10 min in paraformaldehyde (1.5%, Merck, Darmstadt, Germany). After washing for 1 min in dH 2 O, slides were air-dried at room temperature.…”

“…chronic myeloid leukemia (CML), acute myeloid leukemia (AML) FAB M3, and AML M4, other aberrations, such as 5q-, -7, or +8, are of major prognostic impact. Accordingly, the new WHO classification of AML and myelodysplastic syndromes (MDS) is based strongly on the finding of these aberrations [2][3][4] .…”