BACKGROUND: The technique of Fluorescence In-Situ Hybridization (FISH),
a hybrid of cytogenetics and molecular biology has increased the
resolution and application of cytogenetics in various neoplastic
processes. In various types of leukemias, primary investigation by
conventional cytogenetic [CC] technique followed by FISH has increased
our understanding of the abnormal clonal formation involving different
gene region. AIMS: Present study is aimed to use different kinds of
in-house FISH probes in various hematological malignancies and its
correlation with conventional cytogenetic finding. MATERIAL AND
METHODS: Cytogenetic study was carried out in 360 patients either from
peripheral blood or from bone marrow cells suspected for various types
of leukemias. Four of 360 cases were further selected for FISH study by
using different types of in-house probes, such as BAC [Bacterial
Artificial Chromosome], PAC [Phague Artificial Chromosome], alphoid,
PCP [Partial Chromosome Paint] and WCP [Whole Chromosome paint].
RESULTS: The results confirmed breakpoints of inversion 16 and del 16
in case 2 and 3 respectively. Whereas, case 1 did not confirm the
cytogenetic findings of t(15;17) by PML/RARa fusion signals as multiple
cell lines were involved in the patients. PCP and WCP were helpful in
the identification of the marker chromosome in case 1. Telomeric and
centromeric probes confirmed the cytogenetic findings of t(5;7) in case
4. CONCLUSION: We observe from this study that, in addition to the
conventional cytogenetic study, FISH study provide further confirmation
of chromosomal rearrangements. This facilitates our understanding of
the neoplastic process more precisely for the better prognostification
of the patient