Chromosome analysis of non-Hodgkin's lymphomas by fluorescence in situ hybridization

We have recently carried out a cytogenetic survey of a series of non-Hodgkin's lymphomas (NHLs) and identified chromosomal abnormalities in most of the samples studied. A third of these cases, however, had to be recorded as containing derivative or marker chromosomes, whose origins were either partially or completely unknown. In an attempt to further analyse such cases, we have adopted the fluorescence in situ hybridization (FISH) technique. The FISH technique has allowed us to map the myb gene to 6q23, and then to study its position on 6q- derivative chromosomes in the NHL cells. The related FISH technique of chromosome painting has enabled us to identify a marker chromosome in one of our cases as an abnormal X chromosome, and in other cases has allowed 14q+ derivative chromosomes to be further analysed. We have also applied the FISH technique to the analysis of interphase nuclei, and have been able to determine numerical chromosome changes in NHL interphase cells. The application of the FISH technique to the study of NHL cell chromosomes is likely to enable the identification of most chromosomal abnormalities present, and so may reveal the critical events leading to malignant transformation of lymphoid cells.