An extra chromosome 9 derived from either a normal chromosome�9 or a derivative chromosome 9 in a patient with acute myeloid leukemia positive for t(9;11)(p21.3;q23.3): A case report

Abstract

Translocation (9;11)(p21.3;q23.3) is one of the most common lysine methyltransferase 2A (KMT2A)-rearrangements in de novo and therapy-related acute myeloid leukemia (AML). Numerous in vitro and in vivo studies have demonstrated that the KMT2A/MLLT3 super elongation complex subunit (MLLT3) fusion gene on the derivative chromosome 11 serves a crucial role in leukemogenesis. Trisomy 9 as a secondary chromosome change in patients with t(9;11) is relatively rare. The present study reported a unique case of AML with a chromosome 9 trisomy secondary to t(9;11)(p21.3;q23.3) through the cytogenetic analysis of leukemic blood and bone marrow. Further characterization with fluorescence in situ hybridization and array comparative genomic hybridization analysis revealed that this extra chromosome 9 was either a copy of normal chromosome 9 or a derivative chromosome 9. Conversely with the previously reported favorable outcome of AML patients with t(9;11)(p21.3;q23.3), in the present study, the cells with only translocation persisted, whereas the cells with an extra chromosome 9 disappeared following initial chemotherapy. With this unique case, the present study hypothesized that the extra chromosome 9 could serve a crucial role in AML disease progression and contribute to cellular sensitivity to chemotherapy.

Identification of a cryptic submicroscopic deletion using a combination of fluorescence in situ hybridization and array comparative genomic hybridization in a t(3;5)(q25;q35)-positive acute myeloid leukemia patient

“…Array CGH analysis was performed on genomic DNA isolated from an uncultured bone marrow specimen collected during the initial visit using a commercial DNA extraction kit (Puregene Blood Kit; Qiagen, Valencia, CA) to reveal the precise breakpoints of the microdeletion, according to the manufacturer's instructions. [ 13 ] A 2.016-Mb deletion from 3q25.31 to 3q25.32 (position 156,296,873-158,312,638 on hg19) was identified in this patient (Fig. 4 A).…”

Acute Myeloid Leukemia with Concurrent Inversion 16 and Trisomy 9: A Case Report

“…Isolated trisomy 9 is considered a low-to-intermediate risk factor, but in concurrence with other cytogenetic abnormalities, it may result in the rapid progression of disease with consequent poor prognosis. 6 7 10 Delaunay et al showed that the presence of other additional chromosome structure or number abnormalities or persistence of normal metaphases had no significant impact on CR rate. 11 12 13 Its role in prognostic stratification of AML is not well established due to the rarity of its occurrence.…”