Characterization of a Partially Cryptic 3-way Translocation t (8;6;21 (q22.1;q27;q22.3) in AML by Reflex FISH
Journal Title: Indian Journal of Genetics and Molecular Research - Year 2018, Vol 7, Issue 1
Abstract
Context: Variants of standard translocations in leukemia are occasionally suspected initially by fluorescence in-situ hybridization (FISH), due to a different signal pattern. In many cases, this is due to the involvement of an additional chromosome, eading to a complex three-way translocation. If the breakpoints are in the telomeric region, the cryptic translocation may not be visible on karyotyping. We describe here the characterization of a variant AML1/ ETO fusion involving 6q in a patient with AML-M2 Aims: To identify and confirm the extra chromosome involved in a variant AML1/ETO translocation in a case of AML-M2. Settings and Design: First routine FISH for AML1/ ETO and conventional karyotyping was carried out. Reflex FISH was set up on previously Giemsabanded metaphases in two rounds to confirm that chromosome 6 was additionally involved in the AML1/ETO translocation. Material and Methods: Heparinized bone marrow aspirate was obtained from a suspected case of AML-M2. Cytogenetic analysis by routine FISH for AML1/ETO and conventional karyotyping was carried out. Reflex FISH was set up on Giemsabanded metaphases in two rounds using probes for AML1/ETO followed by CEP 6. Results: FISH results showed the presence of a variant signal pattern for translocation AML1/ ETO. Karyotyping of Giemsa-banded metaphases showed suspicion of a three way translocation t (8;6;21) (q22.1;q27;q22.2) which was confirmed by reflex FISH analysis. Conclusions: In cases with suspicion of a cryptic three way translocation, reflex FISH on previously Giemsa-banded metaphases gives a clue about the additional partner chromosome which can be different in each case.
Authors and Affiliations
F. Madon
Keywords
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- EP ID EP630511
- DOI 10.21088/ijgmr.2319.4782.7118.4
- Views 95
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Characterization of a Partially Cryptic 3-way Translocation t (8;6;21 (q22.1;q27;q22.3) in AML by Reflex FISH
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