Bone marrow (BM) failure (BMF) in children and young adults is often suspected to be inherited, but in many cases diagnosis remains uncertain. We studied a cohort of 179 patients (from 173 families) ...with BMF of suspected inherited origin but unresolved diagnosis after medical evaluation and Fanconi anemia exclusion. All patients had cytopenias, and 12.0% presented ≥5% BM blast cells. Median age at genetic evaluation was 11 years; 20.7% of patients were aged ≤2 years and 36.9% were ≥18 years. We analyzed genomic DNA from skin fibroblasts using whole-exome sequencing, and were able to assign a causal or likely causal germ line mutation in 86 patients (48.0%), involving a total of 28 genes. These included genes in familial hematopoietic disorders (GATA2, RUNX1), telomeropathies (TERC, TERT, RTEL1), ribosome disorders (SBDS, DNAJC21, RPL5), and DNA repair deficiency (LIG4). Many patients had an atypical presentation, and the mutated gene was often not clinically suspected. We also found mutations in genes seldom reported in inherited BMF (IBMF), such as SAMD9 and SAMD9L (N = 16 of the 86 patients, 18.6%), MECOM/EVI1 (N = 6, 7.0%), and ERCC6L2 (N = 7, 8.1%), each of which was associated with a distinct natural history; SAMD9 and SAMD9L patients often experienced transient aplasia and monosomy 7, whereas MECOM patients presented early-onset severe aplastic anemia, and ERCC6L2 patients, mild pancytopenia with myelodysplasia. This study broadens the molecular and clinical portrait of IBMF syndromes and sheds light on newly recognized disease entities. Using a high-throughput sequencing screen to implement precision medicine at diagnosis can improve patient management and family counseling.
•Next-generation sequencing broadens the spectrum of germ line mutations in a cohort of patients with likely-inherited BMF.•Salient clinical features and distinct natural histories are consistently found in SAMD9L and SAMD9, MECOM/EVI1, and ERCC6L2 disorders.
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Acute myeloid leukemia (AML) with t(8;21) or inv(16) have been recognized as unique entities within AML and are usually reported together as core binding factor AML (CBF-AML). However, there is ...considerable clinical and biological heterogeneity within this group of diseases, and relapse incidence reaches up to 40%. Moreover, translocations involving CBFs are not sufficient to induce AML on its own and the full spectrum of mutations coexisting with CBF translocations has not been elucidated. To address these issues, we performed extensive mutational analysis by high-throughput sequencing in 215 patients with CBF-AML enrolled in the Phase 3 Trial of Systematic Versus Response-adapted Timed-Sequential Induction in Patients With Core Binding Factor Acute Myeloid Leukemia and Treating Patients with Childhood Acute Myeloid Leukemia with Interleukin-2 trials (age, 1-60 years). Mutations in genes activating tyrosine kinase signaling (including KIT, N/KRAS, and FLT3) were frequent in both subtypes of CBF-AML. In contrast, mutations in genes that regulate chromatin conformation or encode members of the cohesin complex were observed with high frequencies in t(8;21) AML (42% and 18%, respectively), whereas they were nearly absent in inv(16) AML. High KIT mutant allele ratios defined a group of t(8;21) AML patients with poor prognosis, whereas high N/KRAS mutant allele ratios were associated with the lack of KIT or FLT3 mutations and a favorable outcome. In addition, mutations in epigenetic modifying or cohesin genes were associated with a poor prognosis in patients with tyrosine kinase pathway mutations, suggesting synergic cooperation between these events. These data suggest that diverse cooperating mutations may influence CBF-AML pathophysiology as well as clinical behavior and point to potential unique pathogenesis of t(8;21) vs inv(16) AML.
•Recurrent mutations in chromatin modifiers and cohesin were observed in t(8;21) AML, but not inv(16) AML.•t(8;21) AML patients with mutations in kinase signaling plus chromatin modifiers or cohesin members had the highest risk of relapse.
In pediatric relapsed acute myeloid leukemia (AML), optimal reinduction therapy is unknown. Studies suggest that liposomal daunorubicin (DNX; DaunoXome; Galen, Craigavon, United Kingdom) is effective ...and less cardiotoxic, which is important in this setting. These considerations led to a randomized phase III study by the International Berlin-Frankfurt-Münster Study Group.
Patients with relapsed or primary refractory non-French-American-British type M3 AML who were younger than 21 years of age were eligible. Patients were randomly assigned to fludarabine, cytarabine, and granulocyte colony-stimulating factor (FLAG) or to FLAG plus DNX in the first reinduction course. The primary end point was status of the bone marrow (BM) sampled shortly before the second course of chemotherapy (the day 28 BM). Data are presented according to intention-to-treat for all 394 randomly assigned patients (median follow-up, 4.0 years).
The complete remission (CR) rate was 64%, and the 4-year probability of survival (pOS) was 38% (SE, 3%). The day 28 BM status (available in 359 patients) was good (≤ 20% leukemic blasts) in 80% of patients randomly assigned to FLAG/DNX and 70% for patients randomly assigned to FLAG (P = .04). Concerning secondary end points, the CR rate was 69% with FLAG/DNX and 59% with FLAG (P = .07), but overall survival was similar. However, core-binding factor (CBF) AML treated with FLAG/DNX resulted in pOS of 82% versus 58% with FLAG (P = .04). Grade 3 to 4 toxicity was essentially similar in both groups.
DNX added to FLAG improves early treatment response in pediatric relapsed AML. Overall long-term survival was similar, but CBF-AML showed an improved survival with FLAG/DNX. International collaboration proved feasible and resulted in the best outcome for pediatric relapsed AML reported thus far.
Point mutations in the 5' UTR of ankyrin repeat domain 26 (ANKRD26) are associated with familial thrombocytopenia 2 (THC2) and a predisposition to leukemia. Here, we identified underlying mechanisms ...of ANKRD26-associated thrombocytopenia. Using megakaryocytes (MK) isolated from THC2 patients and healthy subjects, we demonstrated that THC2-associated mutations in the 5' UTR of ANKRD26 resulted in loss of runt-related transcription factor 1 (RUNX1) and friend leukemia integration 1 transcription factor (FLI1) binding. RUNX1 and FLI1 binding at the 5' UTR from healthy subjects led to ANKRD26 silencing during the late stages of megakaryopoiesis and blood platelet development. We showed that persistent ANKRD26 expression in isolated MKs increased signaling via the thrombopoietin/myeloproliferative leukemia virus oncogene (MPL) pathway and impaired proplatelet formation by MKs. Importantly, we demonstrated that ERK inhibition completely rescued the in vitro proplatelet formation defect. Our data identify a mechanism for development of the familial thrombocytopenia THC2 that is related to abnormal MAPK signaling.
Diagnosis, treatment, response monitoring, and outcome of pediatric acute myeloid leukemia (AML) have made enormous progress during the past decades. Because AML is a rare type of childhood cancer, ...with an incidence of approximately seven occurrences per 1 million children annually, national and international collaborative efforts have evolved. This overview describes these efforts and includes a summary of the history and contributions of each of the main collaborative pediatric AML groups worldwide. The focus is on translational and clinical research, which includes past, current, and future clinical trials. Separate sections concern acute promyelocytic leukemia, myeloid leukemia of Down syndrome, and relapsed AML. A plethora of novel antileukemic agents that have emerged, including new classes of drugs, are summarized as well. Finally, an important aspect of the treatment of pediatric AML--supportive care--and late effects are discussed. The future is bright, with a wide range of emerging innovative therapies and with more and more international collaboration that ultimately aim to cure all children with AML, with fewer adverse effects and without late effects.
Despite major improvements in outcome over the past decades, acute myeloid leukemia (AML) remains a life-threatening malignancy in children, with current survival rates of ∼ 70%. State-of-the-art ...recommendations in adult AML have recently been published in this journal by Döhner et al. The primary goal of an international expert panel of the International BFM Study Group AML Committee was to set standards for the management, diagnosis, response assessment, and treatment in childhood AML. This paper aims to discuss differences between childhood and adult AML, and to highlight recommendations that are specific to children. The particular relevance of new diagnostic and prognostic molecular markers in pediatric AML is presented. The general management of pediatric AML, the management of specific pediatric AML cohorts (such as infants) or subtypes of the disease occurring in children (such as Down syndrome related AML), as well as new therapeutic approaches, and the role of supportive care are discussed.
Inherited CTPS1, CD27, and CD70 deficiencies in humans have revealed key factors of T‐lymphocyte expansion, a critical prerequisite for an efficient immunity to Epstein–Barr virus (EBV) infection. ...RASGRP1 is a T‐lymphocyte‐specific nucleotide exchange factor known to activate the pathway of MAP kinases (MAPK). A deleterious homozygous mutation in RASGRP1 leading to the loss RASGRP1 expression was identified in two siblings who both developed a persistent EBV infection leading to Hodgkin lymphoma. RASGRP1‐deficient T cells exhibited defective MAPK activation and impaired proliferation that was restored by expression of wild‐type RASGRP1. Similar defects were observed in T cells from healthy individuals when RASGRP1 was downregulated. RASGRP1‐deficient T cells also exhibited decreased CD27‐dependent proliferation toward CD70‐expressing EBV‐transformed B cells, a crucial pathway required for expansion of antigen‐specific T cells during anti‐EBV immunity. Furthermore, RASGRP1‐deficient T cells failed to upregulate CTPS1, an important enzyme involved in DNA synthesis. These results show that RASGRP1 deficiency leads to susceptibility to EBV infection and demonstrate the key role of RASGRP1 at the crossroad of pathways required for the expansion of activated T lymphocytes.
Synopsis
RASGRP1 deficiency is characterized by a high susceptibility to develop Epstein‐Barr virus (EBV)‐driven B‐cell lymphoproliferative disorders such as B‐cell lymphoma like Hodgkin lymphoma. This is caused by defective expansion of activated T cells required for an efficient immune response to EBV.
RASGRP1 is a critical factor of T‐cell proliferation including CD27‐, CD70‐ and CTPS1‐dependent pathways.
RASGRP1 is required for expression of genes involved cell proliferation.
This study emphasizes that T‐cell expansion is a critical step in immunity to EBV.
RASGRP1 deficiency is characterized by a high susceptibility to develop Epstein‐Barr virus (EBV)‐driven B‐cell lymphoproliferative disorders such as B‐cell lymphoma like Hodgkin lymphoma. This is caused by defective expansion of activated T cells required for an efficient immune response to EBV.
Mutations in receptor tyrosine kinase/RAS signaling pathway genes are frequent in core-binding factor (CBF) acute myeloid leukemias (AMLs), but their prognostic relevance is debated. A subset of CBF ...AML patients harbors several signaling gene mutations. Genotyping of colonies and of relapse samples indicates that these arise in independent clones, thus defining a process of clonal interference (or parallel evolution). Clonal interference is pervasive in cancers, but the mechanisms underlying this process remain unclear, and its prognostic impact remains unknown. We analyzed a cohort of 445 adult and pediatric patients with CBF AML treated with intensive chemotherapy and with deep sequencing of 6 signaling genes (KIT, NRAS, KRAS, FLT3, JAK2, CBL). A total of 152 (34%), 167 (38%), and 126 (28%) patients harbored no, a single, and multiple signaling clones (clonal interference), respectively. Clonal interference of signaling mutations was associated with older age (P = .004) and inv(16) subtype (P = .025) but not with white blood cell count or mutations in chromatin or cohesin genes. The median allele frequency of signaling mutations was 31% in patients with a single clone or clonal interference (P = .14). The repertoire of KIT, FLT3, and NRAS/KRAS variants differed between groups. Clonal interference did not affect complete remission rate or minimal residual disease after 1-2 courses, but it did convey inferior event-free survival (P < 10−4), whereas the presence of a single signaling clone did not (P = .44). This inferior outcome was independent of clinical parameters and of the presence of specific signaling clones. Our results suggest that specific clonal architectures can herald distinct prognoses in AML.
•Presence of ≥2 independent subclones in the receptor tyrosine kinase/RAS pathway, defining clonal interference, is found in 28% of CBF AMLs.•Clonal interference predicts shorter event-free survival independently of clinical variables and presence of specific signaling mutations.
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Background
Nuclear protein of the testis (NUT) carcinoma (formerly NUT midline carcinoma) is an aggressive tumor defined by the presence of NUT rearrangement with a poor prognosis. This rare cancer ...is underdiagnosed and poorly treated.
Objective
The primary objective of this study was to describe the clinical, radiologic, and biological features of NUT carcinoma. The secondary objective was to describe the various treatments and assess their efficacy.
Methods
This retrospective multicenter study was based on review of the medical records of children and adults with NUT carcinoma with specific rearrangement or positive anti‐NUT nuclear staining (>50%).
Results
This series of 12 patients had a median age of 18.1 years (ranges: 12.3–49.7 years). The primary tumor was located in the chest in eight patients, the head and neck in three patients, and one patient had a multifocal tumor. Nine patients presented regional lymph node involvement and eight distant metastases. One‐half of patients were initially misdiagnosed. Specific NUT antibody was positive in all cases tested. A transient response to chemotherapy was observed in four of 11 patients. Only two patients were treated by surgery and five received radiotherapy with curative intent. At the end of follow‐up, only one patient was still in remission more than 12 years after the diagnosis. Median overall survival was 4.7 months (95% confidence interval CI: 2.1–17.7).
Conclusion
NUT carcinoma is an aggressive disease refractory to conventional therapy. Early diagnosis by NUT‐specific antibody immunostaining in cases of undifferentiated or poorly differentiated carcinoma to identify the specific rearrangement of NUT gene is useful to propose the optimal therapeutic strategy.
Current immune thrombocytopenia (ITP) guidelines target children and adults, leading to oversimplification. Adolescents and young adults (AYAS) comprise a separate group with distinct health and ...psychosocial issues. This study aimed to describe the clinical presentation and therapeutic strategies of ITP among AYAS. We analyzed data from two large ITP registries (PARC-ITP; CARMEN-France) and included newly diagnosed ITP patients (aged 12-25 years) with initial platelet counts of.
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