Chronic myelomonocytic leukemia with ETV6-ABL1 rearrangement and SMC1A mutation
CANCER GENETICS
Authors: Cessna, Melissa H.; Paulraj, Prabakaran; Hilton, Benjamin; Sadre-Bazzaz, Kianoush; Szankasi, Philippe; Cluff, Alice; Patel, Jay L.; Hoda, Daanish; Toydemir, Reha M.
Abstract
Chronic myelomonocytic leukemia (CMML) is a rare malignant neoplasm of the blood-forming cells in bone marrow characterized by persistent monocytosis. Although most patients with CMML show clonal genetic aberrations, there is no known cytogenetic or molecular genetic finding that is specific to CMML. We report a patient who had a clinical and morphological presentation consistent with CMML. The genetic work-up showed an ETV6-ABL1 fusion consequent to a 9;12 translocation, and a missense mutation in SMC1A (c.1757G>A, p.Arg586Gln). The SMC1A mutations are recurrent, albeit rare, in myeloid malignancies, without an established clinical significance in CMML. ETV6-ABL1 fusion is a rare but recurrent genetic aberration found in various hematologic malignancies involving both the lymphoid and myeloid lineage, but to the best of our knowledge, CMML is an exceptionally rare presentation of ETV6-ABL1 rearranged neoplasm. ETV6-ABL1 fusion is often formed through complex rearrangements, and usually cryptic by routine G-banded chromosome analysis. The diseases associated with this rearrangement generally have an aggressive course, hence detecting or excluding this rearrangement during diagnostic work-up is critical for treatment planning. (C) 2019 Elsevier Inc. All rights reserved.
The incidence, genetic characteristics, and prognosis of leukemia with concurrent pathogenic fusion genes: a series of 25 cases from a large cohort of leukemia patients
CANCER GENE THERAPY
Authors: Chen, Xue; Wang, Fang; Wang, Tong; Zhang, Yang; Ma, Xiaoli; Yuan, Lili; Teng, Wen; Guo, Lei; Liu, Mingyue; Liu, Ming; Chen, Jiaqi; Nie, Daijing; Zhang, Yu; Zhou, Xiaosu; Wang, Mangju; Chen, Kylan N.; Zhu, Ping; Liu, Hongxing
Abstract
Recurrent fusion genes (FGs) with clinical significances in leukemias are mainly mutually exclusive, and the coexistence of different FGs has been rarely reported. In this study, we retrospectively analyzed the incidence, genetic characteristics, and prognosis of leukemias with concurrent pathogenic FGs, which commonly reported in hematological malignancies in 8226 leukemia patients. A total of 25 patients with coexistence of double FGs were identified, accounting for 0.30% of all cases enrolled. More than half of the cases (14/25, 56%) were diagnosed as chronic myeloid leukemia in accelerated or blast phase, another six and five cases were acute myeloid leukemia and acute lymphocytic leukemia, respectively. Most cases (20/25, 80%) carried constitutively activated tyrosine kinases FGs (BCR-ABL1 or ETV6-PDGFRB) and transcription factors associated FGs simultaneously. Of the 11 patients with contemporaneous karyotype, 5 (45%) showed visible chromosomal abnormalities corresponding to both FGs. The concurrency of FGs was often associated with disease progressions. The prognosis was pessimistic for patients with concurrent FGs, even with the combination of targeted therapy and chemotherapy. Performing allogeneic hematopoietic stem cell transplantation as soon as possible after complete remission can ameliorate the dismal prognosis.