Humans ; Child ; Myeloid-Lymphoid Leukemia Protein/genetics* ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Ubiquitin Thiolesterase

Humans ; Leukemia, Myeloid, Acute/genetics* ; Myeloid-Lymphoid Leukemia Protein/genetics* ; Oncogene Proteins, Fusion/genetics* ; Translocation, Genetic

Objective: To summarize and analyze the clinical characteristics and gene mutations of 6 patients with Wiedemann-Steiner syndrome (WDSTS). Methods: To review and analyze the clinical data, including general conditions, clinical manifestations, growth hormone, cranial or pituitary gland magnetic resonance imaging (MRI),gene results and other data, 6 cases with WDSTS admitted to the Department of Endocrinology, Genetics and Metabolism of Jiangxi Provincial Children's Hospital and the Department of Child Care of Pingxiang Maternity and Child Care from April 2017 to February 2021 were recruited. Results: Of the 6 patients, 2 were male and 4 were female. The age of the first visit ranged from 1.0 to 11.2 years. All the 6 children presented with growth retardation and mental retardation and they all had typical facial dysmorphism and hypertrichosis (mainly on the back and limbs). Among them, case 5 had a growth hormone deficiency, and case 2 and 4 had abnormalities revealed by cranial MRI. Variations in KMT2A gene were identified in these 6 patients: c.10900+2T>C,c.10837C>T(p.Gln3613*), c.4332G>A(p.E1444E), c.2508dupC(p.W838Lfs*9), c.11695_11696delinsT(p.T3899Sfs*73), c.9915dupA (p.P3306Tfs*22).Among these variations, c.4332G>A, c.11695_11696delinsT and c.9915dupA were novel mutations. Therefore, the final diagnosis of these patients was WDSTS. Conclusions: Patients presented with short stature and mental retardation, typical facial dysmorphism and hypertrichosis should be considered WDSTS. Whole-exome sequencing plays an important role in disease diagnosis and genetic counseling.
Abnormalities, Multiple ; Child ; Child, Preschool ; Craniofacial Abnormalities ; Female ; Growth Disorders/genetics* ; Histone-Lysine N-Methyltransferase ; Humans ; Hypertrichosis/genetics* ; Infant ; Intellectual Disability/genetics* ; Male ; Myeloid-Lymphoid Leukemia Protein ; Pregnancy ; Syndrome

OBJECTIVE: To investigate the clinical features and prognosis of acute myeloid leukemia (AML) patients with the mixed lineage leukemia (MLL) gene rearrangements AF6 (MLL-AF6) positive. METHODS: In the study, 11 patients who were newly diagnosed with MLL-AF6 positive AML were analyzed retrospectively, related literature was reviewed to clarify the clinical features and prognosis of MLL-AF6 positive patients. RESULTS: Among the 11 patients, there were 6 males and 5 females, with a median age of 36 years. Six patients were diagnosed with AML M5 and five with M4 according to FAB classification (French-American-British classification systems). Gingival swelling and pain occurred in 6 cases and fever occurred in 5 cases. At first diagnosis, the median white blood cells were 55.5×10⁹/L. Immunotype showed the expression of myeloid/monocyte and early stem cell series antigens. The expression level of MLL-AF6 fusion gene (real-time quantitative PCR) was 14.2%-214.5%, and 6/11 cases (54.5%) were associated with high EVI1 gene expression. Mutations of KRAS, TET2, ASXL1, TP53, DNMT3A, and FLT3-ITD were detected by next generation sequencing (NGS) in 4 patients. Chromosome G banding examination showed that 2 cases were t(6;11)(q27, q23) with complex karyotype abnormality, 4 cases with +8 abnormality and 2 cases with normal karyotype. Hematological complete remission (CR) was achieved in 8/11 patients (72.7%) after conventional induction chemotherapy, and primary drug resistance was observed in 3 patients. Two of the eight patients with CR were negative for minimal residual disease (MRD), with a median CR duration of 4.5 months. Two patients with positive MRD and three patients with refractory recurrence underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT), but all died due to leukemia progression. At the end of follow-up on December 1, 2019, 2 patients were alive and 9 died, with median survival time of 9 months. CONCLUSION The AML patients with MLL-AF6 positive were mostly young, the majority of FAB types were M4 and M5, and most of the patients often had fever as the first symptom, with increased white blood cells, accompanied by organ infiltration, and high EVI1 gene expression. The hematological remission rate of routine chemotherapy is not low, but it is difficult to achieve molecular remission, most of which have early recurrence. Early allo-HSCT in a molecular negative state may prolong the CR duration.
Adult ; Female ; Hematopoietic Stem Cell Transplantation ; Humans ; Leukemia, Myeloid, Acute/genetics* ; Male ; Myeloid-Lymphoid Leukemia Protein/genetics* ; Oncogene Proteins, Fusion/genetics* ; Prognosis ; Remission Induction ; Retrospective Studies

OBJECTIVE: To investigate the cytotoxic effect and its mechanism of the micromolecule compound on the leukemia cells. METHODS: The cytotoxic effects of 28 Nilotinib derivatives on K562, KA, KG, HA and 32D cell lines were detected by MTT assays, and the compound Nilo 22 was screen out. Cell apoptosis and cell cycle on leukemia cells were detected by flow cytometry. The effect of compound screened out on leukemogenesis potential of MLL-AF9 leukemia mice GFP RESULTS: Nilo 22 serves as the most outstanding candidate out of 28 Nilotinib derivatives, which impairs leukemia cell lines, but spares normal hematopoietic cell line. Comparing with Nilotinib, Nilo 22 could induce the apoptosis of GFP CONCLUSION Nilo 22 shows a significant cytotoxic effect on mice and human leukemia cells, especially for drug resistance cells. Nilo 22 is a promising anti-leukemia agent to solve the common clinical problems of drug resistance and relapse of leukemia.
Animals ; Apoptosis/drug effects* ; Cell Cycle/drug effects* ; Cell Line, Tumor ; Humans ; Leukemia ; Mice ; Myeloid-Lymphoid Leukemia Protein/genetics* ; Telomerase/metabolism* ; Telomere/metabolism*

OBJECTIVE: To explore the genetic basis for a child with unexplained global developmental delay (GDD), seizure, and facial deformity. METHODS: Whole exome sequencing (WES) was carried out for the patient. Candidate variants were verified by Sanger sequencing of the patient and his parents. RESULTS: WES revealed that the patient has carried a previously unreported de novo heterozygous nonsense c.4906C>T (p.Arg1636Ter) variant of the KMT2A gene, Based on the American College of Medical Genetics and Genomics standards and guidelines, the c.4906C>T variant of KMT2A gene was predicted to be pathogenic (PVS1+ PS2+ PM2+PP3). CONCLUSION The heterozygous nonsense c.4906C>T (p.Arg1636Ter) variant of the KMT2A gene probably underlay the disease in the child. Above finding has enriched the spectrum of pathogenic variants of the KMT2A gene.
Abnormalities, Multiple/genetics* ; Child ; Histone-Lysine N-Methyltransferase/genetics* ; Humans ; Intellectual Disability/genetics* ; Male ; Myeloid-Lymphoid Leukemia Protein/genetics* ; Syndrome

OBJECTIVE: To investigate the clinical characteristics and prognostic influencing factors of adult AML patients with MLL rearrangement. METHODS: Clinical data of 184 adult AML patients with MLL rearrangement treated in our hospital from January 2011 to December 2017 were analyzed retrospectively. The clinical features, immunophenotypic characteristics, cytogenetic characteristics, molecular biological characteristics and gene mutation characteristics were recorded, the survival and prognostic influencing factors of patients were analyzed. RESULTS: Among 184 patients, 94 cases were male, 90 cases were female, median age were 36.0 years, median WBC count were 22.0×10/L, 156 cases as 84.78% for FAB typing M5, and 18 cases as 28.13% for MLL/AF9 gene positive. The median total survival time and recurrence-free survival time of 184 patients were 15.7 months and 13.3 months respectively. The cumulative total survival rate and recurrence-free survival rate by followed-up for 2 years were 36.72% and 29.33% respectively. The cumulative overall survival rate and recurrence-free survival rate of transplant recipients were significantly higher than those of non-transplant recipients by follow-up for 2 years (P＜0.05). Univariate analysis showed that age, baseline WBC count, baseline Hb levels, complete remission after one course of treatment and transplantation or no were the influencing factors of overall survival time in adult AML patients with MLL rearrangement (P＜0.05). Cox regression model multivariate analysis showed that baseline WBC count, complete remission after one course of treatment, and transplantation or no were the independent influencing factors for overall survival time in adult AML patients with MLL rearrangement（P＜0.05）. CONCLUSION Adult AML patients with MLL rearrangement are mostly belong to acute monocytic leukemia, and MLL/AF9 is the most common associated gene. Patients with AML and MLL rearrangement are prone to recurrence after routine chemotherapy. Allo-HSCT treatment is helpful to improve clinical prognosis of patients.
Adult ; Female ; Gene Rearrangement ; Hematopoietic Stem Cell Transplantation ; Humans ; Leukemia, Myeloid, Acute ; Male ; Myeloid-Lymphoid Leukemia Protein ; Prognosis ; Remission Induction ; Retrospective Studies

OBJECTIVE: To explore the clinical-biological characteristics and prognosis of pediatric pro-B cell acute lymphoblastic leukemia (pro-B-ALL). METHODS: A total of 64 patients aged less than 18 years old with pro-BALL were enrolled. Clinical characteristics, therapeutic effect and prognostic factors were retrospectively analyzed. RESULTS: Pro-B-ALL occurred in 6.23% (64/1 028) of pediatric ALL. Among the 64 patients, 35 were male and 29 were female. The median age was 7.0 years (range 0.4-16.0 years) at diagnosis, of which 39% and 6% were ≥ 10 years old and < 1 year old respectively. The median WBC count was 25.5×10 CONCLUSIONS Pediatric pro-B ALL is a heterogeneous disease with clinical and biological diversity. Biological characteristics, such as immunological markers, genetic alterations, and MRD at 3 months after chemotherapy may be important factors for the long-term prognosis.
Adolescent ; Antigens, CD/genetics* ; Child ; Child, Preschool ; Disease-Free Survival ; Female ; Histone-Lysine N-Methyltransferase/genetics* ; Humans ; Infant ; Male ; Myeloid-Lymphoid Leukemia Protein/genetics* ; Neoplasm, Residual/diagnosis* ; Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/genetics* ; Prognosis ; Retrospective Studies

OBJECTIVE: To assess the value of detecting the rearrangement of mixed lineage leukemia (MLL) gene in children with acute mononuclear leukemia (AML). METHODS: Dual-color fluorescence in situ hybridization (FISH) probe was used to detect MLL gene rearrangement in 68 children with AML by interphase FISH. The results were compared with that of conventional G banding chromosomal analysis. RESULTS: Among the 68 children, 28 were detected by FISH with positive hybridization signals, with a detection rate for MLL gene rearrangement being 41.2%. Twelve (17.6%) reciprocal translocations and interruption of 11q23 were detected by G banding analysis. The difference in the detection rates between the two methods was statistically significant (P< 0.05). CONCLUSION The sensitivity of FISH assay for MLL gene rearrangement was significantly higher than that of G banding chromosomal karyotyping. Combined use of both methods for children with AML can improve the detection rate of MLL gene rearrangements and provide crucial clues for clinical diagnosis, treatment and prognosis.
Child ; Chromosomes, Human, Pair 11 ; Gene Rearrangement ; Histone-Lysine N-Methyltransferase ; genetics ; Humans ; In Situ Hybridization, Fluorescence ; Leukemia, Monocytic, Acute ; genetics ; Myeloid-Lymphoid Leukemia Protein ; genetics ; Translocation, Genetic

OBJECTIVE: To investigate the role of bone marrow vascular niche in the development of MLL-AF9 acute myeloid leukemia (AML). METHODS: Transplantation experiments were performed to establish non-radiated MLL-AF9 AML model; the half-bone immunofluorescence staining and tile-scan imaging of two-photon confocal microscopy were used to obtain the data of 3 main bone marrow niche cells; flow cytometry analysis was performed to characterize leukemia cells in different anatomical sites. RESULTS: In the early stage of MLL-AF9 AML, the proportion of leukemia cells in the metaphysis of the femur was significantly higher than that in the diaphysis. The detection of apoptosis and proliferation rate of leukemia cells showed that the percentage of leukemia cells in metaphysis significantly decreased, and the proliferation (S/G/M phase) was also significantly more active. These different features of leukemia cells may relate with different bone marrow microenvironment. The image data of 3 major components of bone marrow niche (endothelial cells, endosteum, megakaryocytes) showed different distribution of blood vessels in metaphysis and diaphysis. Furtherly comparing the spatial distance between leukemia cells and endothelial cells, endosteum, megakaryocytes indicated that leukemia cells are closer to the blood vessels, suggesting the important role of blood vessels in the development of leukemia. Glucose uptake assays and intracellular ROS detection showed that the supportive role of blood vessels for leukemia cells did not related with nutrient metabolism pathway. CONCLUSION The vascular niche plays an important role in the development of leukemia, and does not relate with the transport of nutrients and the elimination of metabolic waste, instead, which may relate with perivascular cytokines or other vascular functions.
Acute Disease ; Apoptosis ; Bone Marrow ; Bone Marrow Cells ; Humans ; Leukemia, Myeloid, Acute ; Myeloid-Lymphoid Leukemia Protein ; Oncogene Proteins, Fusion