Mature B-cell lymphoblastic leukemia with MLL rearrangement: an uncommon and distinct subset of childhood acute leukemia (original) (raw)
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The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society, 2015
MLL (mixed-lineage-leukemia) gene rearrangements are typical for acute leukemia and are associated with an aggressive course of disease, with a worse outcome than comparable case, and thus require intensified treatment. Here we describe a 69-year-old female with adult B cell precursor acute lymphoblastic leukemia (BCP-ALL) with hyperleukocytosis and immunophenotype CD10- and CD19+ with cryptic MLL rearrangements. G-banding at the time of diagnosis showed a normal karyotype: 46,XX. Molecular cytogenetics using multitude multicolor banding (mMCB) revealed a complex rearrangement of the two copies of chromosome 11. However, a locus-specific probe additionally identified that the MLL gene at 11q23.3 was disrupted, and that the 5' region was inserted into the chromosomal sub-band 4q21; thus the aberration involved three chromosomes and five break events. Unfortunately, the patient died six months after the initial diagnosis from serious infections and severe complications. Overall, t...
Blood, 1996
MLL gene rearrangements are associated with an extremely poor prognosis in infants with acute lymphoblastic leukemia (ALL), but little is known about their clinical significance in older children. Therefore, we studied 45 cases of childhood ALL with abnormalities of chromosome 11q23 for rearrangement of the MLL gene to determine if this feature confers a uniformly poor prognosis. MLL gene rearrangements were detected in all 18 cases with the common t(4;11), t(9;11) or t(11;19) translocations, whereas only 5 of 12 patients with either unbalanced or uncommon balanced translocations demonstrated a rearrangement. Abnormalities of the MLL gene were not detected in any of the 15 cases with a deletion or inversion of the chromosomes 11q23 region. The presence of an MLL rearrangement was significantly associated with age less than 1 year (P < .001), leukocyte count >50 x 10(9)/L (P = .003), and the absence of leukemic cell CD10 expression (P < .001). In a stratified statistical ana...
Clinical Cancer Research, 2006
Mixed lineage leukemia (MLL) abnormalities occur in f50% of childhood pro-B acute lymphoblastic leukemia (ALL). However, the incidence and type of MLL rearrangements have not been determined in common ALL (cALL) and CD10+ or CD10À pre-B ALL. Experimental Design: To address this question, we analyzed 29 patients with pro-B ALL, 11patients with CD10À pre-B ALL, 23 pre-B, and 26 cALL patients with CD10 on 20% to 80%, as well as 136 pre-B and 143 cALL patients with CD10 z80% of blasts. They were all enrolled in four Austrian ALL multicenter trials. Conventional cytogenetics were done to detect 11q23 abnormalities and in parallel the potential involvement of the MLL gene was evaluated with a split apart fluorescence in situ hybridization probe set. Results:We found that15 of 29 pro-B ALL, 7 of11CD10À pre-B ALL, and1of 2 French-American-British classification L1 mature B-cell leukemia cases had a MLL rearrangement. However, no 11q23/MLL translocation was identified among the CD10+ pre-B and cALL patients. MLL-rearranged pro-B and CD10À pre-B ALL cases had similar clinical and immunophenotypic (coexpression of CDw65 and CD15) features at initial diagnosis. Conclusions: The striking similarities between the two CD10À ALL subsets imply that CD10À pre-B ALL variants may represent pro-B ALL cases that maintained the propensity to rearrange and express their immunoglobulin heavy chain rather than actual pre-B ALL forms transformed at this later stage of B-cell differentiation. However, direct experimental data are needed to confirm this observation. Rearrangements involving the mixed lineage leukemia (MLL) gene on chromosome band 11q23 represent nonrandom chromosomal abnormalities commonly found in human hematologic malignancies, including both acute lymphoblastic leukemia (ALL; 5-10%) and acute myeloid leukemia (AML; 5%; refs. 1, 2). Although the exact function of the MLL gene is unclear, it displays intrinsic histone methyltransferase activity and is known to play an important role in maintaining a cell type-specific expression of HOX genes, which are necessary for the cellular differentiation process (2, 3). According to most published series, MLL-rearranged B-cell precursor (BCP) ALL can be reliably identified by a distinct immature CD10À/CD24À phenotype that is commonly characterized by the concurrent expression of the myeloid markers CDw65 and CD15, and of the chondroitin sulfate proteoglycan neuron-glial antigen 2 (NG2; refs. 4-7). Due to the observation that the translocation t(4;11) with its molecular counterpart, the MLL/AF4 fusion gene, is the most frequent MLL-specific aberration in infants with pro-B ALL, the CD10 negativity of MLL-rearranged BCP leukemia is commonly regarded as a sign of cellular immaturity (2, 8, 9). Furthermore, the coexpression of CDw65 and CD15 is taken as an evidence that this type of leukemia even represents a transformed upstream lymphomyelomonocytic progenitor cell. As recent collaborative studies showed a marked clinical heterogeneity among MLL-rearranged ALL requiring distinct treatment approaches for different age groups and different 11q23/MLL translocations, it seems essential to screen for MLL abnormalities in pediatric ALL (10-12). Although the topic of MLL in other than the pro-B ALL subset has been recently Human Cancer Biology
MYC rearrangement, a characteristic cytogenetic abnormality of Burkitt lymphoma and several subsets of other mature B-cell neoplasms, typically involves an immunoglobulin gene partner. Herein, we describe a case of precursor B-cell lymphoblastic leukemia harboring a MYC rearrangement with a novel non-immunoglobulin partner locus. The patient was a 4-yr-old Korean boy with ALL of the precursor B-cell immunophenotype. At the time of the second relapse, cytogenetic analyses revealed t(4;8)(q31.1;q24.1) as a clonal evolution. The MYC rearrangement was confirmed by FISH analysis. He died 3 months after the second relapse without achieving complete remission. To our knowledge, this is the first report of a case of MYC rearrangement with a non-immunoglobulin partner in precursor B-cell lymphoblastic leukemia.
Clinical Cancer Research, 2006
Purpose:Mixed lineage leukemia (MLL) abnormalities occur in ∼50% of childhood pro-B acute lymphoblastic leukemia (ALL). However, the incidence and type of MLL rearrangements have not been determined in common ALL (cALL) and CD10+ or CD10− pre-B ALL. Experimental Design: To address this question, we analyzed 29 patients with pro-B ALL, 11 patients with CD10− pre-B ALL, 23 pre-B, and 26 cALL patients with CD10 on 20% to 80%, as well as 136 pre-B and 143 cALL patients with CD10 ≥80% of blasts. They were all enrolled in four Austrian ALL multicenter trials. Conventional cytogenetics were done to detect 11q23 abnormalities and in parallel the potential involvement of the MLL gene was evaluated with a split apart fluorescence in situ hybridization probe set. Results: We found that 15 of 29 pro-B ALL, 7 of 11 CD10− pre-B ALL, and 1 of 2 French-American-British classification L1 mature B-cell leukemia cases had a MLL rearrangement. However, no 11q23/MLL translocation was identified among th...
BMC Medical Genomics, 2009
The presence of MLL rearrangements in acute leukemia results in a complex number of biological modifications that still remain largely unexplained. Armstrong et al. proposed MLL rearrangement positive ALL as a distinct subgroup, separated from acute lymphoblastic (ALL) and myeloblastic leukemia (AML), with a specific gene expression profile. Here we show that MLL, from both ALL and AML origin, share a signature identified by a small set of genes suggesting a common genetic disregulation that could be at the basis of mixed lineage leukemia in both phenotypes.
Molecular Oncology, 2012
Chromosomal rearrangements affecting the MLL gene are associated with high-risk pediatric, adult and therapy-associated acute leukemia. In this study, conventional cytogenetic, fluorescence in situ hybridization, and molecular genetic studies were used to characterize the type and frequency of MLL rearrangements in a consecutive series of 45 Portuguese patients with MLL-related leukemia treated in a single institution between 1998 and 2011. In the group of patients with acute lymphoblastic leukemia and an identified MLL fusion partner, 47% showed the presence of an MLLeAFF1 fusion, as a result of a t(4;11). In the remaining cases, a MLLeMLLT3 (27%), a MLLeMLLT1 (20%), or MLLeMLLT4 (7%) rearrangement was found. The most frequent rearrangement found in patients with acute myeloid leukemia was the MLLeMLLT3 fusion (42%), followed by MLLeMLLT10 (23%), MLLeMLLT1 (8%), MLLeELL (8%), MLLeMLLT4 (4%), and MLLeMLLT11 (4%). In three patients, fusions involving MLL and a septin family gene (SEPT2, SEPT6, and SEPT9), were identified. The most frequently identified chromosomal rearrangements were reciprocal translocations, but insertions and deletions, some cryptic, were also observed. In our series, patients with MLL rearrangements were shown to have a poor prognosis, regardless of leukemia subtype. Interestingly, children with 1 year or less showed a statistically significant better overall survival when compared with both older children and adults. The use of a combined strategy in the initial genetic evaluation of acute leukemia patients allowed us to characterize the pattern of MLL rearrangements in our institution, including our previous discovery of two novel MLL fusion partners, the SEPT2 and CT45A2 genes, and a very rare MLLeMLLT4 fusion variant.
Rearrangement of the MLL gene in acute myeloblastic leukemia: report of two rare translocations
Cancer Genetics and Cytogenetics, 2005
Band 11q23 is known to be involved in translocations and insertions with a variety of partner chromosomes. They lead to MLL rearrangement, resulting in a fusion with numerous genes. We report here 2 male adults in whom a diagnosis of acute myelomonoblastic leukemia (FAB M4) and acute monoblastic leukemia (FAB M5) was made. Conventional cytogenetic techniques showed a 45,XY,t(1;11)(p32;q23),-7 karyotype in the first case and a 46,XY, t(11;17)(q23;q21) in the second case. Fluorescent in situ hybridization (FISH) with a specific MLL probe showed the gene to be disrupted, the 3′ region being translocated on the derivative chromosomes 1 and 17, respectively. Fourteen and 24 patients, including ours, with acute myeloblastic leukemia associated with a t(1;11)(p32;q23) and a t(11;17)(q23;q21), respectively have been reported in the literature. Several patients with the latter translocation have also been identified to have acute lymphoblastic leukemia (ALL). Although both translocations are preferentially associated with monocytic differentiation, the t(11;17)(q23;q21) is more common in adults and has been reported in many patients with ALL, compared to the t(1;11)(p32;q23).