[Interphasic in situ fluorescent hybridization (FISH) in 4 cases of myeloid neoplasias with chromosome 7 changes].

The use of FISH as a complement to the conventional cytogenetic studies is of great help in attaining a better characterisation of the chromosome anomalies present in haematological malignancies, such as chromosome 7 monosomy. A study was carried out in three cases of acute non-lymphoblastic leukaemia and a myelodysplastic syndrome with chromosome 7 involvement, as shown by conventional cytogenetic studies. The Cocktail probe for chromosome 7 (DZ1, DZ2) was used (Oncor) in performing in situ hybridation. A monosomic cell line for chromosome 7, undetected by conventional techniques, was disclosed with this procedure in two of the cases. In the remaining two patients the monosomy of chromosome 7 was confirmed, although at percentages different from those attained with the conventional methods.