Cytogenetics -- Fatigue and Weight Loss


To further characterize the single cell abnormality noted in the karyotypic analysis, Fluorescence In Situ Hybridization (FISH) was performed to determine whether the BCR/ABL gene rearrangement was present in a larger population of interphase cells from this specimen. The procedure utilized fluorescent probes of different hues, each specific for the chromosomal segment of interest. In this case, the BCR gene on the long arm of chromosome 9 and the ABL gene on the long arm of chromosome 22 are the genes of interest. In a normal interphase cell without a translocation, deletion, or duplication of the above genes, the observer should note 4 separate signals (2 red, 2 green), which represent the normal allelic complement. This is noted in the normal control, which is hybridized simultaneously with the specimen cells of interest. Two hundred of the patient's cells, primarily in interphase, were examined for the presence of the BCR/ABL gene rearrangement by FISH with the Oncor m- BCR/ABL translocation DNA probe (Oncor Inc., Gaithersburg, MD). These cells were derived from 24 hour harvests of unstimulated bone marrow aspirate cell cultures. The BCR/ABL gene rearrangement was observed by molecular cytogenetic analysis (FISH) in the vast majority of the 200 interphase cells examined (92.5%). Note the presence of a fused red and green fluorescent signal (which appears yellow) in the pictured cell, in addition to a separate red and green signal representing the nontranslocated genes on the other pair of chromosomes 9 and 22. The FISH results are expressed:



IndexCME Case StudiesFeedbackHome