Translocation (1;11)(q23;p15), a novel simple variant of translocation (7;11)(p15;p15), in a patient with AML (M2) accompanied by non-Hodgkin lymphoma and gastric cancer

Rare NUP98::PRRX1 fusion transcript in a therapy-related acute myeloid leukemia associated with del(7q) following chemotherapy for diffuse large B-cell lymphoma

BACKGROUND

Therapy-related acute myeloid leukemia (t-AML) is increasingly recognized as a treatment complication in patients receiving chemotherapy, radiotherapy, or immunosuppressive agents for primary neoplasms. NUP98::PRRX1 fusion gene, caused by t(1;11)(q23;p15), is a rare recurrent cytogenetic alteration in leukemia, and only seven cases with NUP98::PRRX1 were reported so far.

METHODS

A 53-year-old female patient was diagnosed with t-AML after 20 months of complete remission (CR) from diffuse large B-cell lymphoma (DLBCL). Conventional karyotype, fluorescence in situ hybridization (FISH), and DNA/RNA next-generation sequence (NGS) were used to detect genetic abnormalities.

RESULTS

Abnormal karyotype of 46, XX, t(1;11)(q25;p15), del(7)(q22) was revealed. NUP98 gene rearrangement and del(7)(q22) were verified by FISH. Further, RNA NGS detected NUP98::PRRX1 fusion transcript, and DNA NGS detected KRAS gene mutation. The patient achieved CR after a combined chemotherapy regimen containing BCL-2 inhibitor and underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT), but she died of leukemia recurrence 14 months later.

CONCLUSIONS

Novel targeted drugs may provide opportunities for patients with NUP98::PRRX1 to undergo allo-HSCT. However, since the cases of carrying the NUP98::PRRX1 are limited, more patients with this genetic change need to be investigated to elucidate the prognostic significance.

Acute Myelogenous Leukemia with the t(7;7)(p15;p22) Translocation, a Novel Simple Variant of t(7;11)(p15;p15) Translocation: First Description

The t(7;11)(p15;p15) translocation is a recurrent genetic abnormality associated with acute myelogenous leukemia (AML). The translocation results in a fusion between the nucleoporin 98 and homeobox genes. We describe a case of AML with t(7; 7)(p15;p22) translocation, which is a novel simple variant of the t(7;11)(p15;p15) translocation. A 66-year-old woman presented with subcutaneous hemorrhage in both forearms. Laboratory test revealed hyperleukocytosis (white blood cell count: 97,800 cells/µL (blasts, 51.0%)), anemia (hemoglobin level: 7.6 g/dL), thrombocytopenia (platelet count: 6.5 × 10⁴/μL), and hyperfibrinolysis (elevated d-dimer level: 12.4 µg/mL; fibrin/fibrinogen degradation products: 26.9 µg/mL). The patient was diagnosed with AML; the blast morphology was unclassifiable according to the French-American-British classification. Flow cytometry CD45 gating revealed that the blasts expressed CD34, CD13, CD33, and CD117. G-banding of tumor cells revealed the t(7;7)(p15;p22) translocation [20/20]. The patient underwent chemotherapy. At 48 days of admission, the patient died of multiple organ failure. The t(7;7)(p15;p22) translocation involved chromosome 7p15, indicating its association with the homeobox genes. To the best of our knowledge, this is the first report of a patient with AML with the t(7;7)(p15;p22) translocation, which is a simple novel variant of the t(7;11)(p15;p15) translocation.

Rare t(1;11)(q23;p15) in therapy-related myelodysplastic syndrome evolving into acute myelomonocytic leukemia: a case report and review of the literature

Balanced chromosome rearrangements are the hallmark of therapy-related leukemia that develops in patients treated with topoisomerase II inhibitors. Many of these rearrangements involve recurrent chromosomal sites and associated genes (11q23/MLL, 21q22.3/AML1, and 11p15/NUP98), which can interact with a variety of partner genes. One such rearrangement is the rare t(1;11)(q23;p15), which involves juxtaposition of the homeobox gene PMX1 (PRRX1) and NUP98. We report on an additional patient with t(1;11) who presented with myelodysplastic syndrome (MDS) subsequent to treatment for a pleomorphic liposarcoma. With time, the patient's disorder progressed to acute myelomonocytic leukemia with cytogenetic evidence of clonal evolution. To our knowledge, this is the first report of a patient presenting with a myelodysplastic syndrome with isolated t(1;11) (q23;p15), which evolved into therapy-related acute myeloid leukemia (t-AML). This patient is the third reported with this cytogenetic rearrangement and t-AML, and is compared with the other two reports of t(1;11)(q23;p15).

A t(4;11)(q21;p15) in a case of T-cell lymphoma and a case of acute myelogenous leukemia

The translocation (4;11)(q21;p15) has been observed in acute lymphoblastic as well as acute myeloid leukemias (ALL and AML, respectively). We report the first case of T-cell lymphoma with t(4;11)(q21;p15) and a case of AML. The clinical history of and cytogenetics in the latter is suggestive of a secondary leukemia; his karyotype revealed emergence of a t(3;11)(q21;q13) in addition to the t(4;11). Previously reported cases with t(4;11)(q21;p15) are reviewed, clinical and morphological characteristics of cases with t(4;11)(q21;q23) and t(4;11)(q21;p15) are compared, and chromosome abnormalities involving the NUP98 gene in hematologic malignant disorders are reviewed.

NUP98 gene fusions in hematologic malignancies

Acute leukemia is associated with a wide spectrum of recurrent, non-random chromosomal translocations. Molecular analysis of the genes involved in these translocations has led to a better understanding of both the causes of chromosomal rearrangements as well as the mechanisms of leukemic transformation. Recently, a number of laboratories have cloned translocations involving the NUP98 gene on chromosome 11p15.5, from patients with acute myelogenous leukemia (AML), myelodysplastic syndrome (MDS), chronic myelogenous leukemia (CML), and T cell acute lymphoblastic leukemia (T-ALL). To date, at least eight different chromosomal rearrangements involving NUP98 have been identified. The resultant chimeric transcripts encode fusion proteins that juxtapose the N-terminal GLFG repeats of NUP98 to the C-terminus of the partner gene. Of note, several of these translocations have been found in patients with therapy-related acute myelogenous leukemia (t-AML) or myelodysplastic syndrome (t-MDS), suggesting that genotoxic chemotherapeutic agents may play an important role in generating chromosomal rearrangements involving NUP98.