Objective: To investigate the genetic and genomic profiling of juvenile myelomonocytic leukemia (JMML) and factors affecting its survival rate. Methods: Clinical characteristics, cytogenetics, molecular biology results and survival status of children with 27 JMML cases admitted to the Hematology Department of Children's Hospital, Capital Institute of Pediatrics from December 2012 to December 2021 were analyzed retrospectively, and the outcomes of the children were followed up. Kaplan-Meier method was used for survival analysis. Univariate analysis was used for analyzing factors affecting the overall survival (OS) rates of patients who received hematopoietic stem cell transplantation (HSCT). Log-Rank test was used for comparison of survival curves. Results: Among 27 JMML cases, there were 11 males and 16 females. The age of disease onset was 28 (11,52) months. There are 20 cases of normal karyotype, 4 cases of monosomy 7, 1 case of trisomy 8,1 case of 11q23 rearrangement and 1 case of complex karyotype. A total of 39 somatic mutations were detected.Those involved in RAS signal pathway were the highest (64%(25/39)), among which PTPN11 mutation was the most frequent (44% (11/25)). A total of 17 cases (63%) received HSCT, 8 cases (30%) did not receive HSCT, and 2 cases (7%) lost follow-up. For children receiving transplantation, the follow-up time after transplantation was 47 (11,57) months. The 1-year OS rate of high-risk transplantation group (17 cases) and high-risk non transplantation group (6 cases) was (88±8)% and (50±20)% respectively, with a statistically significant difference (χ²=5.01, P=0.025). The 5-year OS rate of the high-risk transplantation group was (75±11)%. The survival time of those who relapsed or progressed to acute myeloid leukemia after transplantation was significantly shorter than that of those who did not relapse (χ²=6.80, P=0.009). The OS rate of patients with or without PTPN11 mutation was (81±12) % and (67±19)% respectively (χ²=0.85, P=0.356). Conclusions: The main pathogenesis involved in JMML is gene mutation related to RAS signaling pathway, and the most common driver gene of mutation is PTPN11. Allogeneic HSCT can significantly improve the survival rate of high-risk JMML patients. The recurrence or progression after transplantation was related to poor prognosis.
Male ; Female ; Child ; Humans ; Child, Preschool ; Leukemia, Myelomonocytic, Juvenile/therapy* ; Retrospective Studies ; Survival Analysis ; Mutation ; Hematopoietic Stem Cell Transplantation

OBJECTIVES: To investigate the clinical features of juvenile myelomonocytic leukemia (JMML) and their association with prognosis. METHODS: Clinical and prognosis data were collected from the children with JMML who were admitted from January 2008 to December 2016, and the influencing factors for prognosis were analyzed. RESULTS: A total of 63 children with JMML were included, with a median age of onset of 25 months and a male/female ratio of 3.2∶1. JMML genetic testing was performed for 54 children, and PTPN11 mutation was the most common mutation and was observed in 23 children (43%), among whom 19 had PTPN11 mutation alone and 4 had compound PTPN11 mutation, followed by NRAS mutation observed in 14 children (26%), among whom 12 had NRAS mutation alone and 2 had compound NRAS mutation. The 5-year overall survival (OS) rate was only 22%±10% in these children with JMML. Of the 63 children, 13 (21%) underwent hematopoietic stem cell transplantation (HSCT). The HSCT group had a significantly higher 5-year OS rate than the non-HSCT group (46%±14% vs 29%±7%, P<0.05). There was no significant difference in the 5-year OS rate between the children without PTPN11 gene mutation and those with PTPN11 gene mutation (30%±14% vs 27%±10%, P>0.05). The Cox proportional-hazards regression model analysis showed that platelet count <40×10⁹/L at diagnosis was an influencing factor for 5-year OS rate in children with JMML (P<0.05). CONCLUSIONS The PTPN11 gene was the most common mutant gene in JMML. Platelet count at diagnosis is associated with the prognosis in children with JMML. HSCT can improve the prognosis of children with JMML.
Child ; Humans ; Male ; Female ; Child, Preschool ; Leukemia, Myelomonocytic, Juvenile/therapy* ; Prognosis ; Genetic Testing ; Mutation ; Hematopoietic Stem Cell Transplantation

OBJECTIVE: To investigate the clinical characteristics, prognostic factors and efficacy of hypomethylating agent (HMA) in patients with chronic myelomonocytic leukemia (CMML). METHODS: The clinical data of 37 newly diagnosed patients with CMML was analyzed retrospectively, and their clinical characteristics and the efficacy of HMA were summarized. Kaplan-Meier and Log-rank test were used for univariate survival analysis, and Cox proportional hazards regression model was used for multivariate analysis. RESULTS: The median age at diagnosis was 67 years old. Their common manifestations included fatigue, bleeding, abnormal blood routine and fever. Most patients had splenomegaly. According to FAB classification, there were 6 cases of myelodysplastic CMML and 31 cases of myeloproliferative CMML, while according to WHO classification, 8 patients belonged to CMML-0, 9 patients to CMML-1 and 20 patients to CMML-2. At the time of diagnosis, the median white blood cell count was 32.84×10⁹/L, median hemoglobin (Hb) was 101 g/L, median platelet count was 65×10⁹/L, median absolute monocyte count was 9.53×10⁹//L, median absolute neutrophil count (ANC) was 11.29×10⁹//L and median lactate dehydrogenase (LDH) was 374 U/L. Cytogenetic abnormalities were found in 4 cases among the 31 patients who underwent karyotype analysis or fluorescence in situ hybridization detection. There were 12 patients who had analyzable results and gene mutations were identified in 11 cases, including ASXL1, NRAS, TET2, SRSF2 and RUNX1. Among the 6 patients who were treated with HMA and could be evaluated for efficacy, 2 patients achieved complete remission, 1 patient achieved partial remission and 2 patients achieved clinical benefit. Compared with the non-HMA treatment group, overall survival (OS) time was not significantly prolonged in the HMA treatment group. Univariate analysis showed that Hb<100 g/L, ANC≥12×10⁹/L, LDH≥250 U/L and peripheral blood (PB) blasts ≥5% were significantly associated with poor OS, while WHO classification CMML-2, Hb<100 g/L, ANC≥12×10⁹/L, LDH≥250 U/L and PB blasts≥5% were significantly associated with poor leukemia-free survival (LFS) (P<0.05). Multivariate analysis showed that ANC≥12×10⁹/L and PB blasts≥5% were significantly associated with poor OS and LFS (P<0.05). CONCLUSION CMML has high heterogeneity in clinical characteristics, genetic changes, prognosis and treatment response. HMA can not significantly improve the survival of CMML patients. ANC≥12×10⁹/L and PB blasts≥5% are independent prognostic factors of OS and LFS in patients with CMML.
Humans ; Aged ; Leukemia, Myelomonocytic, Chronic/genetics* ; Retrospective Studies ; In Situ Hybridization, Fluorescence ; Survival Analysis ; Prognosis

Objective: To explore the molecular features of chronic myelomonocytic leukemia (CMML) . Methods: According to 2022 World Health Organization (WHO 2022) classification, 113 CMML patients and 840 myelodysplastic syndrome (MDS) patients from March 2016 to October 2021 were reclassified, and the clinical and molecular features of CMML patients were analyzed. Results: Among 113 CMML patients, 23 (20.4%) were re-diagnosed as acute myeloid leukemia (AML), including 18 AML with NPM1 mutation, 3 AML with KMT2A rearrangement, and 2 AML with MECOM rearrangement. The remaining 90 patients met the WHO 2022 CMML criteria. In addition, 19 of 840 (2.3%) MDS patients met the WHO 2022 CMML criteria. At least one gene mutation was detected in 99% of CMML patients, and the median number of mutations was 4. The genes with mutation frequency ≥ 10% were: ASXL1 (48%), NRAS (34%), RUNX1 (33%), TET2 (28%), U2AF1 (23%), SRSF2 (21.1%), SETBP1 (20%), KRAS (17%), CBL (15.6%) and DNMT3A (11%). Paired analysis showed that SRSF2 was frequently co-mutated with ASXL1 (OR=4.129, 95% CI 1.481-11.510, Q=0.007) and TET2 (OR=5.276, 95% CI 1.979-14.065, Q=0.001). SRSF2 and TET2 frequently occurred in elderly (≥60 years) patients with myeloproliferative CMML (MP-CMML). U2AF1 mutations were often mutually exclusive with TET2 (OR=0.174, 95% CI 0.038-0.791, Q=0.024), and were common in younger (<60 years) patients with myelodysplastic CMML (MD-CMML). Compared with patients with absolute monocyte count (AMoC) ≥1×10(9)/L and <1×10(9)/L, the former had a higher median age of onset (60 years old vs 47 years old, P<0.001), white blood cell count (15.9×10(9)/L vs 4.4×10(9)/L, P<0.001), proportion of monocytes (21.5% vs 15%, P=0.001), and hemoglobin level (86 g/L vs 74 g/L, P=0.014). TET2 mutations (P=0.021) and SRSF2 mutations (P=0.011) were more common in patients with AMoC≥1×10(9)/L, whereas U2AF1 mutations (P<0.001) were more common in patients with AMoC<1×10(9)/L. There was no significant difference in the frequency of other gene mutations between the two groups. Conclusion: According to WHO 2022 classification, nearly 20% of CMML patients had AMoC<1×10(9)/L at the time of diagnosis, and MD-CMML and MP-CMML had different molecular features.
Humans ; Aged ; Middle Aged ; Leukemia, Myelomonocytic, Chronic/genetics* ; Prognosis ; Splicing Factor U2AF/genetics* ; Mutation ; Myelodysplastic Syndromes/genetics* ; Leukemia, Myeloid, Acute/genetics*

Humans ; Leukemia, Myelomonocytic, Juvenile/therapy*

Humans ; Leukemia, Myelomonocytic, Chronic/therapy* ; Mutation ; Myelodysplastic Syndromes

OBJECTIVE: To explore the clinical efficacy and safety of unrelated umbilical cord blood transplantation (UCBT) in the treatment of Juvenile myelomonocytic leukemia (JMML). METHODS: The clinical data of 5 children with JMML who were treated with unrelated UCBT from October 2011 to July 2019 were retrospectively analyzed. The age of onset for the five children (male) ranged from 0.4 to 5.0 years old, with a median age of 1.5 years old. All the patients received myeloablative conditioning regimen without ATG to whom cyclosporine A (CsA) with short-term mycophenolate mofetil (MMF) was given for GVHD prophylaxis. RESULTS: Four children acquired engraftment. One patient received secondary haploidentical hematopoietic stem cell transplantation because of the failure in the first unrelated UCBT. Grade Ⅲ to Ⅳ aGVHD occurred in 2 cases and was controlled, and none of the patients developed cGVHD. Three cases achieved long-time disease free survival，and no patient relapsed. CONCLUSION UCBT is an effective treatment for children with JMML.
Child ; Child, Preschool ; Cord Blood Stem Cell Transplantation ; Graft vs Host Disease ; Hematopoietic Stem Cell Transplantation ; Humans ; Infant ; Leukemia, Myelomonocytic, Juvenile ; Male ; Retrospective Studies ; Transplantation Conditioning

Abstract　　Single cell sequencing technology is different from traditional sequencing method, which is based on population cell average level. It has been widely used in many fields and made great progress in the application of malignant hematological diseases. In this review, the principle, methodology and application of single cell sequencing technology in malignant hematological diseases are summarized briefly, including the study of the pathogenesis in myelodysplastic syndrome, the mechanism of transformation into leukemia, accurate diagnosis and classification, differential diagnosis, evaluation of targeted drug therapeutic efficacy and exploration of biomarkers; specific diagnostic indicators for myeloproliferative diseases, progression of disease monitoring and epidemiological studies; moreover, the pathogenesis and drug resistance of acute myeloid leukemia (AML), which can provide reference for the diagnosis and research of malignant hematological diseases.
Hematologic Diseases ; Humans ; Leukemia, Myeloid, Acute ; Myelodysplastic Syndromes ; Myeloproliferative Disorders ; Sequence Analysis

OBJECTIVE: To analyze the gene mutations of children with juvenile myelomonocytic leukemia (JMML) and their correlation with clinical characteristics. METHODS: The genetic mutation results and clinical data of 19 children with JMML in Fujian from January 2015 to December 2018 were collected and analyzed retrospectively. According to the results of gene mutation, they were divided into PTPN11 gene mutation group and non-PTPN11 gene mutation group, and the clinical characteristics and prognosis of children with JMML between two groups were compared. RESULTS: Among the 19 children with JMML, 14 cases were male and 5 cases were female, and male/female ratio was 2.8∶1. The median age at diagnosis was 13(3-48) months, and 14 cases (73.68%) were less than 2 years old. Abdominal distension and pyrexia were the common initial symptoms, and all the children with JMML had splenomegaly. The median white blood cell count was 39.82(4.53-103.4)×10 CONCLUSION JMML is more common in male infancy and toddlerhood, and the main gene mutation types are PTPN11 and Ras mutations. Because the JMML children with PTPN11 mutations show particularly rapid disease progression, if there is no timely intervention, most children die in a short period of time. Therefore, early HSCT may improve the prognosis of the children with JMML.
Child ; Female ; Hematopoietic Stem Cell Transplantation ; Humans ; Infant ; Leukemia, Myelomonocytic, Juvenile/genetics* ; Male ; Mutation ; Prognosis ; Protein Tyrosine Phosphatase, Non-Receptor Type 11/genetics* ; Retrospective Studies

OBJECTIVE: To investigate the clinical significance of the targeted next-generation sequencing assay for patients with suspected myeloid malignancies. METHODS: A total of 39 hematopenia patients with suspected myeloid malignamies in Department of Hematology of The Affiliated Huai'an No.1 People's Hospital of Nanjing Medical University from January 2018 to April 2019 were treated, 20 hot spot genes of myelodysplastic syndrome (MDS) were detected. RESULTS: Regarding the diagnostic type, there were 7 cases of idiopathic cytopenia of undetermined significance (ICUS), 8 cases of clonal cytopenias of undetermined significance (CCUS) and 24 cases of myeloid myeloid malignancies which included 18 cases of MDS, 4 cases of myelodysplastic/myeloproliferative neoplasms (MDS/MPN) and 2 cases of acute myeloid leukemia. Positive mutation was detected in 70.8% (17/24) of myeloid malignancy patients , and 72.7% (16/22) in MDS and MDS/MPN patients. The main mutation types were ASXL1, TET2 and RUNX1. Compared with gene negative group, there were no significant differences in sex, age (＜60 years old or ≥60 years old), proportion of bone marrow blast cells (＜5% or≥5%) and cytogenetics (good, medium and poor) (P＞0.05). Furthermore, all 8 CCUS patients showed positive mutation, and the incidence of double or multiple mutation in CCUS group was significantly lower than that of the MDS and MDS/MPN group (37.5% vs 54.5%) (P=0.002). The mutation types between the two groups were similar, and there was no significant difference in variant allele frequency (P＞0.05). CONCLUSION Our results suggest that there are high rates of double or multiple mutations in myeloid malignancies, especially in patients with MDS and MDS/MPN. Targeted sequencing assay can improve the diagnosis of myeloid malignancies, and guide clinical treatment.
Humans ; Leukemia, Myeloid, Acute/genetics* ; Middle Aged ; Mutation ; Myelodysplastic Syndromes/genetics* ; Myelodysplastic-Myeloproliferative Diseases ; Patients