A Rare Case of Methemoglobinemia after Ifosfamide Infusion in a 3-Year-Old Patient Treated for T-ALL.

Methemoglobinemia is a potentially life-threatening, rare condition in which the oxygen-carrying capacity of hemoglobin is diminished. We present the case of a 3-year-old boy treated for T-cell acute lymphoblastic leukemia (T-ALL) who developed methemoglobinemia (MetHb 57.1%) as a side effect of ifosfamide administration. Due to his critical condition, the patient was transferred to the intensive care unit (ICU). The therapy included methylene blue administration, an exchange transfusion, catecholamine infusion, and steroids. Improving the general condition allowed for continuing chemotherapy without ifosfamide and completion of the HR2 block. Vigilance for methemoglobinemia as a very rare side effect should be widespread when using ifosfamide in the treatment protocols.

Metabolic Profiling as an Approach to Differentiate T-Cell Acute Lymphoblastic Leukemia Cell Lines Belonging to the Same Genetic Subgroup.

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive tumor mainly affecting children and adolescents. It is driven by multiple genetic mutations that together define the leukemic phenotype. Interestingly, based on genetic alterations and/or deregulated expression, at least six genetic subgroups have been recognized. The TAL/LMO subgroup is one of the most represented genetic subgroups, characterizing 30-45% of pediatric T-ALL cases. The study of lipid and metabolic profiles is increasingly recognized as a valuable tool for comprehending the development and progression of tumors. In this study, metabolic and lipidomic analysis via LC/MS have been carried out on four T-ALL cell lines belonging to the TAL/LMO subgroup (Jurkat, Molt-4, Molt-16, and CCRF-CEM) to identify new potential metabolic biomarkers and to provide a subclassification of T-ALL cell lines belonging to the same subgroup. A total of 343 metabolites were annotated, including 126 polar metabolites and 217 lipid molecules. The statistical analysis, for both metabolic and lipid profiles, shows significant differences and similarities among the four cell lines. The Molt-4 cell line is the most distant cell line and CCRF-CEM shows a high activity in specific pathways when compared to the other cell lines, while Molt-16 and Jurkat show a similar metabolic profile. Additionally, this study highlighted the pathways that differ in each cell line and the possible enzymes involved using bioinformatic tools, capable of predicting the pathways involved by studying the differences in the metabolic profiles. This experiment offers an approach to differentiate T-ALL cell lines and could open the way to verify and confirm the obtained results directly in patients.

Honokiol induces apoptosis and autophagy in dexamethasone-resistant T-acute lymphoblastic leukemia CEM-C1 cells.

Objective: To study whether and, if so, how honokiol overcome dexamethasone resistance in DEX-resistant CEM-C1 cells. Methods: We investigated the effect of honokiol (0-20 µM) on cell proliferation, cell cycle, cell apoptosis and autophagy in DEX-resistant CEM-C1 cells and DEX-sensitive CEM-C7 cells. We also determined the role of c-Myc protein and mRNA in the occurrence of T-ALL associated dexamethasone resistance western blot and reverse transcription-qPCR (RT-qPCR) analysis. Results: Cell Counting Kit (CCK)-8 assay shows that DEX-resistant CEM-C1 cell lines were highly resistant to dexamethasone with IC50 of 364.1 ± 29.5 µM for 48 h treatment. However, upon treatment with dexamethasone in combination with 1.5 µM of honokiol for 48 h, the IC50 of CEM-C1 cells significantly decreased to 126.2 ± 12.3 µM, and the reversal fold was 2.88. Conversely, the IC50 of CEM-C7 cells was not changed combination of dexamethasone and honokiol as compared to that of CEM-C7 cells treated with dexamethasone alone. It has been shown that honokiol induced T-ALL cell growth inhibition by apoptosis and autophagy via downregulating cell cycle-regulated proteins (Cyclin E, CDK4, and Cyclin D1) and anti-apoptotic proteins BCL-2 and upregulating pro-apoptotic proteins Bax and led to PARP cleavage. Honokiol may overcome dexamethasone resistance in DEX-resistant CEM-C1 cell lines via the suppression of c-Myc mRNA expression. Conclusion: The combination of honokiol and DEX were better than DEX alone in DEX-resistant CEM-C1 cell lines. Honokiol may regulate T-ALL-related dexamethasone resistance by affecting c-Myc.

The CNS microenvironment promotes leukemia cell survival by disrupting tumor suppression and cell cycle regulation in pediatric T-cell acute lymphoblastic leukemia.

A major obstacle in improving survival in pediatric T-cell acute lymphoblastic leukemia is understanding how to predict and treat leukemia relapse in the CNS. Leukemia cells are capable of infiltrating and residing within the CNS, primarily the leptomeninges, where they interact with the microenvironment and remain sheltered from systemic treatment. These cells can survive in the CNS, by hijacking the microenvironment and disrupting normal functions, thus promoting malignant transformation. While the protective effects of the bone marrow niche have been widely studied, the mechanisms behind leukemia infiltration into the CNS and the role of the CNS niche in leukemia cell survival remain unknown. We identified a dysregulated gene expression profile in CNS infiltrated T-ALL and CNS relapse, promoting cell survival, chemoresistance, and disease progression. Furthermore, we discovered that interactions between leukemia cells and human meningeal cells induced epigenetic alterations, such as changes in histone modifications, including H3K36me3 levels. These findings are a step towards understanding the molecular mechanisms promoting leukemia cell survival in the CNS microenvironment. Our results highlight genetic and epigenetic alterations induced by interactions between leukemia cells and the CNS niche, which could potentially be utilized as biomarkers to predict CNS infiltration and CNS relapse.

Hyperactive STAT5 hijacks T cell receptor signaling and drives immature T cell acute lymphoblastic leukemia.

T cell acute lymphoblastic leukemia (T-ALL) is an aggressive immature T cell cancer. Mutations in IL7R have been analyzed genetically, but downstream effector functions such as STAT5A and STAT5B hyperactivation are poorly understood. Here, we studied the most frequent and clinically challenging STAT5BN642H driver in T cell development and immature T cell cancer onset and compared it with STAT5A hyperactive variants in transgenic mice. Enhanced STAT5 activity caused disrupted T cell development and promoted an early T cell progenitor-ALL phenotype, with upregulation of genes involved in T cell receptor (TCR) signaling, even in absence of surface TCR. Importantly, TCR pathway genes were overexpressed in human T-ALL and mature T cell cancers and activation of TCR pathway kinases was STAT5 dependent. We confirmed STAT5 binding to these genes using ChIP-Seq analysis in human T-ALL cells, which were sensitive to pharmacologic inhibition by dual STAT3/5 degraders or ZAP70 tyrosine kinase blockers in vitro and in vivo. We provide genetic and biochemical proof that STAT5A and STAT5B hyperactivation can initiate T-ALL through TCR pathway hijacking and suggest similar mechanisms for other T cell cancers. Thus, STAT5 or TCR component blockade are targeted therapy options, particularly in patients with chemoresistant clones carrying STAT5BN642H.

Low expression of miR-182 caused by DNA hypermethylation accelerates acute lymphocyte leukemia development by targeting PBX3 and BCL2: miR-182 promoter methylation is a predictive marker for hypomethylation agents + BCL2 inhibitor venetoclax.

BACKGROUND: miR-182 promoter hypermethylation frequently occurs in various tumors, including acute myeloid leukemia, and leads to low expression of miR-182. However, whether adult acute lymphocyte leukemia (ALL) cells have high miR-182 promoter methylation has not been determined. METHODS: To assess the methylation status of the miR-182 promoter, methylation and unmethylation-specific PCR analysis, bisulfite-sequencing analysis, and MethylTarget™ assays were performed to measure the frequency of methylation at the miR-182 promoter. Bone marrow cells were isolated from miR-182 knockout (182KO) and 182 wild type (182WT) mice to construct BCR-ABL (P190) and Notch-induced murine B-ALL and T-ALL models, respectively. Primary ALL samples were performed to investigate synergistic effects of the hypomethylation agents (HMAs) and the BCL2 inhibitor venetoclax (Ven) in vitro. RESULTS: miR-182 (miR-182-5P) expression was substantially lower in ALL blasts than in normal controls (NCs) because of DNA hypermethylation at the miR-182 promoter in ALL blasts but not in normal controls (NCs). Knockout of miR-182 (182KO) markedly accelerated ALL development, facilitated the infiltration, and shortened the OS in a BCR-ABL (P190)-induced murine B-ALL model. Furthermore, the 182KO ALL cell population was enriched with more leukemia-initiating cells (CD43+B220+ cells, LICs) and presented higher leukemogenic activity than the 182WT ALL population. Furthermore, depletion of miR-182 reduced the OS in a Notch-induced murine T-ALL model, suggesting that miR-182 knockout accelerates ALL development. Mechanistically, overexpression of miR-182 inhibited proliferation and induced apoptosis by directly targeting PBX3 and BCL2, two well-known oncogenes, that are key targets of miR-182. Most importantly, DAC in combination with Ven had synergistic effects on ALL cells with miR-182 promoter hypermethylation, but not on ALL cells with miR-182 promoter hypomethylation. CONCLUSIONS: Collectively, we identified miR-182 as a tumor suppressor gene in ALL cells and low expression of miR-182 because of hypermethylation facilitates the malignant phenotype of ALL cells. DAC + Ven cotreatment might has been applied in the clinical try for ALL patients with miR-182 promoter hypermethylation. Furthermore, the methylation frequency at the miR-182 promoter should be a potential biomarker for DAC + Ven treatment in ALL patients.

Key candidate genes and pathways in T lymphoblastic leukemia/lymphoma identified by bioinformatics and serological analyses.

T-cell acute lymphoblastic leukemia (T-ALL)/T-cell lymphoblastic lymphoma (T-LBL) is an uncommon but highly aggressive hematological malignancy. It has high recurrence and mortality rates and is challenging to treat. This study conducted bioinformatics analyses, compared genetic expression profiles of healthy controls with patients having T-ALL/T-LBL, and verified the results through serological indicators. Data were acquired from the GSE48558 dataset from Gene Expression Omnibus (GEO). T-ALL patients and normal T cells-related differentially expressed genes (DEGs) were investigated using the online analysis tool GEO2R in GEO, identifying 78 upregulated and 130 downregulated genes. Gene Ontology (GO) and protein-protein interaction (PPI) network analyses of the top 10 DEGs showed enrichment in pathways linked to abnormal mitotic cell cycles, chromosomal instability, dysfunction of inflammatory mediators, and functional defects in T-cells, natural killer (NK) cells, and immune checkpoints. The DEGs were then validated by examining blood indices in samples obtained from patients, comparing the T-ALL/T-LBL group with the control group. Significant differences were observed in the levels of various blood components between T-ALL and T-LBL patients. These components include neutrophils, lymphocyte percentage, hemoglobin (HGB), total protein, globulin, erythropoietin (EPO) levels, thrombin time (TT), D-dimer (DD), and C-reactive protein (CRP). Additionally, there were significant differences in peripheral blood leukocyte count, absolute lymphocyte count, creatinine, cholesterol, low-density lipoprotein, folate, and thrombin times. The genes and pathways associated with T-LBL/T-ALL were identified, and peripheral blood HGB, EPO, TT, DD, and CRP were key molecular markers. This will assist the diagnosis of T-ALL/T-LBL, with applications for differential diagnosis, treatment, and prognosis.

Limited dsRNA editing impedes leukemia stem cells.

Understanding the mechanisms underlying the generation and maintenance of leukemia stem cells (LSCs) is crucial for the development of effective therapies against T cell acute lymphoblastic leukemia (T-ALL). In a recent study, Rivera et al. discovered that elevated adenosine deaminase acting on RNA (ADAR)-1-mediated RNA editing is a distinguishing feature of T-ALL relapse, and that ADAR1 suppresses apoptosis triggered by the double-stranded (ds)RNA-sensing pathway.

Bartonella henselae Infection and Lymphadenopathy in a Patient With T Cell Acute Lymphoblastic Leukemia.

Patients undergoing therapy for T cell acute lymphoblastic leukemia are at risk of infections during their treatment course. Cat scratch disease caused by Bartonella hensalae can masquerade as leukemic relapse and cause systemic infection. Obtaining a thorough exposure history may aid clinicians in making the diagnosis.

Integrated analysis of transcriptome and genome variations in pediatric T cell acute lymphoblastic leukemia: data from north Indian tertiary care center.

INTRODUCTION: T-cell acute lymphoblastic leukemia (T-ALL) is a genetically heterogeneous disease with poor prognosis and inferior outcome. Although multiple studies have been perform on genomics of T-ALL, data from Indian sub-continent is scarce. METHODS: In the current study we aimed to identify the genetic variability of T-ALL in an Indian cohort of pediatric (age ≤ 12 years) T-ALL patients (n = 25) by whole transcriptome sequencing along with whole exome sequencing and correlated the findings with clinical characteristics and disease outcome. RESULTS: The median age was 7 years (range 3 -12 years). RNA sequencing revealed a definitive fusion event in 14 cases (56%) (including a novel fusions) with STIL::TAL1 in 4 (16%), followed by NUP21::ABL1, TCF7::SPI1, ETV6::HDAC8, LMO1::RIC3, DIAPH1::JAK2, SETD2::CCDC12 and RCBTB2::LPAR6 in 1 (4%) case each. Significant aberrant expression was noted in RAG1 (64%), RAG2 (80%), MYCN (52%), NKX3-1 (52%), NKX3-2 (32%), TLX3 (28%), LMO1 (20%) and MYB (16%) genes. WES data showed frequent mutations in NOTCH1 (35%) followed by WT1 (23%), FBXW7 (12%), KRAS (12%), PHF6 (12%) and JAK3 (12%). Nearly 88.2% of cases showed a deletion of CDKN2A/CDKN2B/MTAP genes. Clinically significant association of a better EFS and OS (p=0.01) was noted with RAG2 over-expression at a median follow up of 22 months, while a poor EFS (p=0.041) and high relapse rate (p=0.045) was observed with MYB over-expression. CONCLUSION: Overall, the present study demonstrates the frequencies of transcriptomic and genetic alterations from Indian cohort of pediatric T-ALL and is a salient addition to current genomics data sets available in T-ALL.

Case report: Two pediatric cases of long-term leukemia-free survival with relapsed acute T-lymphoblastic leukemia treated with donor CD7 CAR-T cells bridging to haploidentical stem cell transplantation.

Introduction: Patients with relapsed/refractory (r/r) acute T-lymphoblastic leukemia (T-ALL) have a poor prognosis. We developed donor CD7 chimeric antigen receptor T (CAR-T) cells to salvage r/r T-ALL patients and obtained encouraging results. Patients who had not received allogeneic (allo-) hematopoietic stem cell transplantation (HSCT) before CAR-T therapy would develop pancytopenia and immunodeficiency for a long period after CD7 CAR-T therapy; therefore, allo-HSCT is needed in these patients. Here, we report two pediatric r/r T-ALL patients who received donor CD7 CAR-T bridging to allo-HSCT with leukemia-free survival (LFS) and sustained negative minimal residual disease for >2 years. Case presentation: Patient 1 was a 10-year-old boy who visited our hospital because of a T-ALL relapse with multiple lymphadenopathies without discomfort. The patient did not achieve remission after one course of induction chemotherapy. The patient then received donor (his father) CD7 CAR-T cells and achieved complete remission (CR). Thirty days after the first CAR-T cell infusion, he received allo-HSCT, and his father was also the donor. His LFS was >3 years. Patient 2 was an 8-year-old boy who was admitted to our hospital with relapsed T-ALL with fever, cough, and mild dyspnea. He did not achieve remission after one course of induction chemotherapy; therefore, he received donor (his father) CD7 CAR-T cells and achieved CR. Twenty-six days after CAR-T cell infusion, the patient received allo-HSCT, with his father as the donor. He has survived for >2 years free of leukemia. At the last follow up, both patients were alive and presented a good quality of life. Conclusion: The long-term survival of these two patients supports the use of CD7 CAR-T therapy bridging to allo-HSCT as an effective and safe treatment with the capacity to make r/r T-ALL a curable disease, similar to r/r acute B-lymphoblastic leukemia.

Nelarabine-containing salvage therapy and conditioning regimen in transplants for pediatric T-cell acute lymphoblastic leukemia and lymphoma.

Therapy for relapsed or refractory (r/r) T-cell acute lymphoblastic leukemia (T-ALL) and T-cell lymphoblastic lymphoma (T-LBL) in children is challenging, and new treatment methods are needed. We retrospectively analyzed eight patients with r/r T-ALL (five patients) and T-LBL (three patients) who were treated with nelarabine (NEL) plus etoposide, cyclophosphamide, and intrathecal therapy, administered 3 days apart. Five patients achieved a complete response, and the other three achieved a partial response (PR). All patients underwent hematopoietic stem cell transplantation (HSCT) after two cycles of treatment, except for one patient who received one cycle. Three patients who had previously received HSCT were treated with reduced-intensity conditioning regimens, including fludarabine, melphalan, and NEL; one survived for over 5 years after the second HSCT. Grade 2 neuropathy occurred in one patient, but other severe toxicities commonly associated with NEL were not observed during NEL administration in combination with chemotherapy. The 2-year overall survival and event-free survival rates were 60.0% and 36.5%, respectively. The addition of NEL to reinduction chemotherapy was useful in achieving remission and did not lead to excessive toxicity. In addition, a conditioning regimen, including NEL, appeared to be effective in patients who had previously undergone HSCT.

[Severe consciousness disturbance after cord blood transplantation for relapsed T lymphoblastic lymphoma].

T-lymphoblastic leukemia/lymphoma (T-ALL/LBL) has a poor prognosis. Nelarabine has recently shown relatively good results in patients with relapsed or refractory T-ALL/LBL, but requires careful monitoring for neurological complications. A 50-year-old man with early recurrence of T-LBL after allogenic peripheral blood stem cell transplantation received nelarabine monotherapy and achieved complete remission after 1 cycle. He then received umbilical cord blood transplantation, and experienced sustained disturbance of consciousness. He later died of multiple organ failure, and autopsy suggested that nelarabine-induced leukoencephalopathy had caused the disturbance of consciousness. This case suggests that physicians should carefully monitor patients for neurological complications and consider imaging follow-up and consultation with a neurologist.

[Characteristics and Prognosis in Adult Patients with Early T-Cell Precursor Acute Lymphoblastic Leukemia/Lymphoma from Multicenter].

OBJECTIVE: To analyze the clinical characteristics, treatment, and prognosis of adult patients with early T-cell precursor acute lymphoblastic leukemia/lymphoma (ETP-ALL/LBL). METHODS: Clinical data of 113 T lymphoblastic leukemia/lymphoma (T-ALL/LBL) patients from January 2006 to January 2019 were collected from three hematology research centers, including Peking University Third Hospital, the First Medical Center of Chinese PLA General Hospital and Institute of Hematology and Blood Diseases Hospital, Chinese Medical University. The clinical characteristics and prognosis of ETP-ALL/LBL patients were analyzed compared with non-ETP-ALL/LBL patients. RESULTS: In 113 T-ALL/LBL patients, 13 cases (11.5%) were diagnosed as ETP-ALL/LBL, including 11 males, with a median age of 28(18-53) years. Compared with non-ETP-ALL/LBL patients, there were no significant differences in age, sex, incidence of large mediastinal mass, clinical stage, international prognostic index (IPI) score, white blood cell (WBC) count and lactate dehydrogenase (LDH) level among ETP-ALL/LBL patients. Among 13 ETP-ALL/LBL patients, 9 cases (69.2%) achieved complete remission (CR), and there was no statistically significant difference in response rate induced by chemotherapy between ETP-ALL/LBL patients and non-ETP-ALL/LBL patients. Among patients who received chemotherapy without allogeneic hematopoietic stem cell transplantation (allo-HSCT), ETP-ALL/LBL group had a worse 5-year overall survival (OS) rate compared with non-ETP-ALL/LBL group (0 vs 7.1%, P =0.008), while in patients with allo-HSCT, there was no significant difference for 5-year OS rate between the two group (37.5% vs 40.2%, P >0.05). Multivariate Cox regression analysis showed that CR after induction therapy, allo-HSCT, and LDH level were independent prognostic factors affecting T-ALL/LBL patients. CONCLUSION: No significant difference in response rate induced by chemotherapy is observed between ETP-ALL/LBL and non-ETP-ALL/LBL patients. Allo-HSCT consolidation after induction of remission therapy may have significant favorable influence on OS for patients with ETP-ALL/LBL.

Philadelphia chromosome-positive T-cell acute lymphoblastic leukemia: a case report.

Philadelphia chromosome-positive (Ph+) T-cell acute lymphoblastic leukemia (T-ALL) is a rare and aggressive type of acute leukemia. The Philadelphia chromosome is the hallmark of chronic myeloid leukemia (CML). The differentiation between Ph+ T-ALL and T-cell lymphoblastic crisis of CML may be problematic in some cases. Here, we report a rare case of de novo Ph+ T-ALL that presented a diagnostic challenge. The overall clinical, immunophenotypic, cytogenetic, and xenotransplantation results suggest a diagnosis of Ph+ T-ALL. The patient was treated with induction chemotherapy including imatinib followed by haploidentical stem cell transplantation and achieved complete remission.

Effect of Ferroptosis Inducers and Inhibitors on Cell Proliferation in Acute Leukemia.

BACKGROUND/AIM: Ferroptosis refers to an iron-dependent mechanism of regulated cell death that is attributable to lipid peroxidation. Ferroptosis has been documented as a therapeutic target for various solid cancers; nonetheless, its implication in leukemia remains ambiguous. Therefore, this study aimed at investigating the impact of ferroptosis inducers and inhibitors on in vitro leukemia cell line proliferation. MATERIALS AND METHODS: Six leukemia cell lines, including acute myeloid leukemia (AML)-derived MV4-11, THP-1, HL-60, and U-937, and T-lymphoblastic leukemia (T-ALL)-derived Jurkat and KOPT-K1 with activating NOTCH1 mutations, were assessed. Erastin, which interrupts cystine uptake and depletes intracellular glutathione, and RAS-selective lethal 3 (RSL3), which suppresses glutathione peroxidase 4 (GPX4), were employed as ferroptosis inducers. Lipid peroxidation-arresting ferrostatin-1 and deferoxamine were used as ferroptosis inhibitors. Cells were cultured with these compounds and cell proliferation was assessed using a colorimetric assay. Additionally, signaling protein expression was monitored using immunoblotting, and the outcome of GPX4 knockdown was evaluated. RESULTS: Ferroptosis inducers suppressed proliferation in all cell lines except THP-1 for Erastin and THP-1 and Jurkat for RSL3. Although the ferroptosis inhibitors did not affect cell proliferation, they rescued inducer-mediated growth suppression. Ferroptosis inducers impeded MYC and cyclin D3 expression in certain cell lines and NOTCH1 signaling in T-ALL cells. GPX4 knockdown and RSL3 treatment interrupted MYC and cyclin D3 expression, respectively, in four cell lines. CONCLUSION: Ferroptosis inducers may serve as potential candidates for novel molecular therapy against AML and T-ALL.

Renin-Angiotensin System Inhibitors Suppress the Growth of Leukemia Cells.

BACKGROUND/AIM: The renin-angiotensin system (RAS) regulates blood pressure. The RAS is also related to cell growth, and its activation has been reported in various cancer cells. Therefore, we investigated the effects of RAS inhibitors on the in vitro growth of leukemia cell lines. MATERIALS AND METHODS: THP-1, MV4-11, and TMD7 cells derived from acute myeloid leukemia, K-562 cells from chronic myeloid leukemia, and Jurkat and KOPT-K1 cells from T-lymphoblastic leukemia (T-ALL) with NOTCH1 mutations were used. We used four RAS inhibitors: the renin inhibitor aliskiren, angiotensin-converting enzyme 1 inhibitor captopril, angiotensin II type 1 receptor antagonist azilsartan, and angiotensin II type 2 receptor antagonist PD123319. Cells were cultured with the inhibitors and cell growth was assessed using a colorimetric assay. The expression of signaling proteins was assessed using immunoblotting. RESULTS: Treatment with aliskiren, azilsartan, or PD123319 suppressed the growth of all cell lines. Captopril treatment suppressed the growth of K-562, KOPT-K1, and MV4-11 cells. Flow cytometric analysis revealed that the growth suppression was due to the induction of apoptosis. Their suppressive effects on normal lymphocytes were milder than those on leukemia cells. Treatment with these inhibitors decreased MYC expression, induced caspase3 and PARP cleavage, and suppressed mTOR signaling. The treatment also suppressed NOTCH1 signaling in T-ALL cells. CONCLUSION: RAS inhibitors can be repurposed as molecular-targeted drugs for leukemia. However, the concentrations of the inhibitors were much higher than those in the plasma of patients with hypertension. Therefore, further investigation is required for their clinical use.

Williams-Beuren syndrome in pediatric T-cell acute lymphoblastic leukemia: A rare case report and review of literature.

BACKGROUND: Williams-Beuren syndrome (WBS) is a rare genetic disorder caused by hemizygous microdeletion of contiguous genes on chromosome 7q11.23. Although the phenotype features extensive heterogeneity in severity and performance, WBS is not considered to be a predisposing factor for cancer development. Currently, hematologic cancers, mainly Burkitt lymphoma, are rarely reported in patients with WBS. Here in, we report a unique case of T-cell acute lymphoblastic leukemia in a male child with WBS. METHODS: This retrospective study analyzed the clinical data of this case receiving chemotherapy were analyzed. This is a retrospective study. RESULTS: The patient, who exhibited a typical WBS phenotype and presented with hemorrhagic spots. Chromosomal genome-wide chip analysis (CMA) revealed abnormalities on chromosomes 7 and 9. The fusion gene STIL-TAL1 and mutations in BCL11B, NOTCH1, and USP7 have also been found and all been associated with the occurrence of T-cell leukemia. The patient responded well to the chemotherapy. CONCLUSION: To the best of our knowledge, this is the first reported case of WBS in T-cell acute lymphoblastic leukemia. We want to emphasize that the occurrence of leukemia in this patient might be related to the loss of 7q11.23 and microdeletion of 9p21.3 (including 3 TSGs), but the relationship between WBS and malignancy remains unclear. Further studies are required to clarify the relationship between WBS and malignancy.