RESUMO
BACKGROUND: Congenital neutropenias are characterized by severe infections and a high risk of myeloid transformation; the causative genes vary across ethnicities. The Israeli population is characterized by an ethnically diverse population with a high rate of consanguinity. OBJECTIVE: To evaluate the clinical and genetic spectrum of congenital neutropenias in Israel. METHODS: We included individuals with congenital neutropenias listed in the Israeli Inherited Bone Marrow Failure Registry. Sanger sequencing was performed for ELANE or G6PC3, and patients with wild-type ELANE/G6PC3 were referred for next-generation sequencing. RESULTS: Sixty-five patients with neutropenia were included. Of 51 patients with severe congenital neutropenia, 34 were genetically diagnosed, most commonly with variants in ELANE (15 patients). Nine patients had biallelic variants in G6PC3, all of consanguineous Muslim Arab origin. Other genes involved were SRP54, JAGN1, TAZ, and SLC37A4. Seven patients had cyclic neutropenia, all with pathogenic variants in ELANE, and seven had Shwachman-Diamond syndrome caused by biallelic SBDS variants. Eight patients (12%) developed myeloid transformation, including six patients with an unknown underlying genetic cause. Nineteen (29%) patients underwent hematopoietic stem cell transplantation, mostly due to insufficient response to treatment with granulocyte-colony stimulating factor or due to myeloid transformation. CONCLUSIONS: The genetic spectrum of congenital neutropenias in Israel is characterized by a high prevalence of G6PC3 variants and an absence of HAX1 mutations. Similar to other registries, for 26% of the patients, a molecular diagnosis was not achieved. However, myeloid transformation was common in this group, emphasizing the need for close follow-up.
Assuntos
Síndrome Congênita de Insuficiência da Medula Óssea , Mutação , Neutropenia , Humanos , Neutropenia/genética , Neutropenia/congênito , Neutropenia/epidemiologia , Neutropenia/diagnóstico , Masculino , Israel/epidemiologia , Feminino , Criança , Síndrome Congênita de Insuficiência da Medula Óssea/genética , Síndrome Congênita de Insuficiência da Medula Óssea/diagnóstico , Pré-Escolar , Adolescente , Predisposição Genética para Doença , Adulto , Transplante de Células-Tronco Hematopoéticas , Lactente , Consanguinidade , Glucose-6-Fosfatase/genética , Alelos , Sistema de Registros , Sequenciamento de Nucleotídeos em Larga Escala , Adulto Jovem , Fenótipo , Estudos de Associação GenéticaRESUMO
BACKGROUND: Pediatric immune thrombocytopenia (ITP) may precede systemic autoimmune disorders. In adolescent patients with ITP, routine screening for systemic lupus erythematosus (SLE) may be performed by testing for antinuclear antibody (ANA) titer. Hydroxychloroquine (HCQ) is a safe and effective immunomodulatory drug in patients with SLE but rarely used in ITP. We analyzed the platelet count response and safety of HCQ in treating pediatric patients with SLE-related ITP. METHODS: A retrospective study including pediatric patients with ITP and definite or incomplete SLE, who were treated with HCQ during 2010-2021. SLE was defined by ANA titer ≥ 1:160 as measured by immunofluorescence and ≥10 points according to the 2019 EULAR/ACR 2019 classification criteria, while patients with incomplete SLE achieved a score < 10. Complete response (CR) of the platelet count was defined as platelet count > 100 × 109/L; partial response (PR) as platelet count 30-100 × 109/L and exceeding ≥ twice baseline counts. RESULTS: Of the 17 patients included (median age 15.5 years; IQR 3.6), 15 (88.2%) were female, 13 had definite SLE, and four had incomplete SLE. HCQ was initiated at a median of 17 months after ITP diagnosis with a median platelet count of 38 × 109/L (IQR 28). At 8 weeks, 8 (47.1%) patients responded, including 6 (35.3%) achieving CR. After one year, the overall response was 82.4%, with the remaining patients having stable platelet counts requiring no additional ITP therapy. The response was maintained at a median follow-up of 42 months. No adverse effects to HCQ were noted. CONCLUSION: Pediatric patients with SLE-related ITP may benefit from treatment with HCQ.
Assuntos
Lúpus Eritematoso Sistêmico , Púrpura Trombocitopênica Idiopática , Trombocitopenia , Adolescente , Humanos , Feminino , Criança , Masculino , Hidroxicloroquina/uso terapêutico , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Estudos Retrospectivos , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Trombocitopenia/tratamento farmacológicoRESUMO
Background: Children with hemato-oncological diseases or following stem cell transplantation (SCT) are at high risk for life-threatening infections; sepsis in this population constitutes a substantial proportion of pediatric intensive care unit (PICU) admissions. The current pediatric prognostic scoring tools to evaluate illness severity and mortality risk are designed for the general pediatric population and may not be adequate for this vulnerable subpopulation. Methods: Retrospective analysis was performed on all PICU admissions for sepsis in children with hemato-oncological diseases or post-SCT, in a single tertiary pediatric hospital between 2008 and 2021 (n = 233). We collected and analyzed demographic, clinical, and laboratory data and outcomes for all patients, and evaluated the accuracy of two major prognostic scoring tools, the Pediatric Logistic Organ Dysfunction-2 (PELOD-2) and the Pediatric Risk of Mortality III (PRISM III). Furthermore, we created a new risk-assessment model that contains additional parameters uniquely relevant to this population. Results: The survival rate for the cohort was 83%. The predictive accuracies of PELOD-2 and PRISM III, as determined by the area under the curve (AUC), were 83% and 78%, respectively. Nine new parameters were identified as clinically significant: age, SCT, viral infection, fungal infection, central venous line removal, vasoactive inotropic score, bilirubin level, C-reactive protein level, and prolonged neutropenia. Unique scoring systems were established by the integration of these new parameters into the algorithm; the new systems significantly improved their predictive accuracy to 91% (p = 0.01) and 89% (p < 0.001), respectively. Conclusions: The predictive accuracies (AUC) of the PELOD-2 and PRISM III scores are limited in children with hemato-oncological diseases admitted to PICU with sepsis. These results highlight the need to develop a risk-assessment tool adjusted to this special population. Such new scoring should represent their unique characteristics including their degree of immunosuppression and be validated in a large multi-center prospective study.
Assuntos
Hematologia , Neoplasias , Sepse , Criança , Humanos , Lactente , Estudos Retrospectivos , Estudos Prospectivos , Prognóstico , Unidades de Terapia Intensiva Pediátrica , Cuidados Críticos , Mortalidade HospitalarRESUMO
While neonatal alloimmune thrombocytopenia (NAIT) is the most common cause of severe neonatal thrombocytopenia good clinical predictors are lacking. We analyzed cases of neonatal thrombocytopenia in Schneider Children's Medical Center of Israel to pinpoint qualifiers of NAIT (NAIT+) in comparison to non-NAIT (NAIT-) thrombocytopenia. Patient and maternal data were retrospectively collected on all thrombocytopenic newborns undergoing a workup for NAIT in our tertiary center between 2001 and 2016. Among 26 thrombocytopenic neonates, the mean nadir in NAIT+ patients (25×10 9 /L) was significantly lower than NAIT- patients (64×10 9 /L) ( P <0.001). 61.5% of NAIT+ infants required treatment compared with 23% of non-NAIT ( P =0.015). NAIT+ patients also required more therapeutic modalities than infants with NAIT- thrombocytopenia. Human platelet antigen (HPA)-1a and HPA-5b alloantibodies most frequently caused NAIT. In summary, thrombocytopenia in NAIT+ was significantly more severe compared with NAIT- and more likely to require treatment. In addition, despite the varied ethnic population in Israel, the HPA alloantibodies found in our population were most similar to those common in Western countries. In the absence of rigorous prenatal screening options, we suggest platelet counts below 40 to 50×10 9 /L in a healthy newborn be considered most suggestive for NAIT and warrant urgent NAIT-specific analysis.
Assuntos
Antígenos de Plaquetas Humanas , Doenças do Recém-Nascido , Trombocitopenia Neonatal Aloimune , Gravidez , Lactente , Feminino , Criança , Humanos , Recém-Nascido , Trombocitopenia Neonatal Aloimune/terapia , Trombocitopenia Neonatal Aloimune/epidemiologia , Isoanticorpos , Estudos Retrospectivos , Contagem de PlaquetasRESUMO
INTRODUCTION: Genetic diagnosis of congenital hematological disorders is complicated by the overlap of the clinical and laboratory presentation across different diseases and the large number of genes involved in each syndrome. Nonetheless, an accurate genetic diagnosis is essential for directing the follow-up and treatment program of the patients, as well as for identifying asymptomatic family members, choosing a non-affected related donor for hematopoietic stem cell transplantation and for offering a prenatal diagnosis. In recent years, a novel method of targeted next generation sequencing using gene panels was developed. In our laboratory, gene panels were incorporated for the diagnosis of congenital hematological disorders, including inherited bone marrow failure syndromes and rare anemias, and for the detection of somatic variant in the bone marrow. It is of utmost importance that an in-depth analysis will include a correlation of the genetic variants with the clinical and laboratory presentation and with the family history. Here, we demonstrate the importance of performing a timely genetic diagnosis in patients with congenital hematological disorders.
Assuntos
Anemia , Transplante de Células-Tronco Hematopoéticas , Humanos , Anemia/congênito , SíndromeRESUMO
Mono-allelic germline disruptions of the transcription factor GATA2 result in a propensity for developing myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML), affecting more than 85% of carriers. How a partial loss of GATA2 functionality enables leukemic transformation years later is unclear. This question has remained unsolved mainly due to the lack of informative models, as Gata2 heterozygote mice do not develop hematologic malignancies. Here we show that two different germline Gata2 mutations (TgErg/Gata2het and TgErg/Gata2L359V) accelerate AML in mice expressing the human hematopoietic stem cell regulator ERG. Analysis of Erg/Gata2het fetal liver and bone marrow-derived hematopoietic cells revealed a distinct pre-leukemic phenotype. This was characterized by enhanced transition from stem to progenitor state, increased proliferation, and a striking mitochondrial phenotype, consisting of highly expressed oxidative-phosphorylation-related gene sets, elevated oxygen consumption rates, and notably, markedly distorted mitochondrial morphology. Importantly, the same mitochondrial gene-expression signature was observed in human AML harboring GATA2 aberrations. Similar to the observations in mice, non-leukemic bone marrows from children with germline GATA2 mutation demonstrated marked mitochondrial abnormalities. Thus, we observed the tumor suppressive effects of GATA2 in two germline Gata2 genetic mouse models. As oncogenic mutations often accumulate with age, GATA2 deficiency-mediated priming of hematopoietic cells for oncogenic transformation may explain the earlier occurrence of MDS/AML in patients with GATA2 germline mutation. The mitochondrial phenotype is a potential therapeutic opportunity for the prevention of leukemic transformation in these patients.
Assuntos
Deficiência de GATA2 , Leucemia Mieloide Aguda , Síndromes Mielodisplásicas , Criança , Humanos , Camundongos , Animais , Deficiência de GATA2/genética , Síndromes Mielodisplásicas/patologia , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Medula Óssea/patologia , Células-Tronco Hematopoéticas/metabolismo , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Fator de Transcrição GATA2/genética , Fator de Transcrição GATA2/metabolismoRESUMO
BACKGROUND: Recent studies show a high risk of developing malignancy in patients with Fanconi anemia. The most common solid tumor in this condition is head and neck squamous cell carcinoma (HNSCC) and there is often uncertainty and about disease behavior as well as chemotherapy and radiation response. OBJECTIVES: To describe and characterize HNSCC among Fanconi anemia patients on the Israeli Fanconi Registry. METHODS: Our study population included patients in Israel's inherited bone marrow failure registry who were diagnosed with Fanconi anemia between1980 and 2016. Demographic, clinical, and laboratory data were collected from patient charts. RESULTS: From the collected data, HNSCC was confirmed in 6/111 (5.4%) Fanconi anemia patients; 1 (17%) had classic HNSCC risk factors of tobacco abuse and 4 (56%) had undergone primary surgery. The 3 (50%) receiving concurrent chemoradiotherapy had mild side effects, while half developed metachronous primary malignancy, and all developed > 2 primary malignancies. The overall median survival of the patients in our study was 14 (0.5-57) months. CONCLUSIONS: Fanconi anemia patients have a very high risk of developing HNSCC. Proactive screening for malignancies is needed for the head and neck regions. We also found that chemoradiotherapy can be used safely in high-stage cancers.
Assuntos
Anemia de Fanconi , Neoplasias de Cabeça e Pescoço , Anemia de Fanconi/complicações , Anemia de Fanconi/epidemiologia , Anemia de Fanconi/terapia , Neoplasias de Cabeça e Pescoço/epidemiologia , Neoplasias de Cabeça e Pescoço/terapia , Humanos , Israel/epidemiologia , Sistema de Registros , Carcinoma de Células Escamosas de Cabeça e Pescoço/epidemiologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/terapiaRESUMO
In patients with inherited bleeding disorders, thrombus development poses a challenge in balancing the management of thrombosis and bleeding. Pediatric antithrombotic therapy guidelines do not address the treatment of a thrombus in the setting of a bleeding disorder. We present a case series of four children with inherited bleeding disorders presenting with cerebral sinus venous thrombosis and bleeding, in order to summarize the different therapeutic approaches and outcomes of these patients.
Assuntos
Transtornos Herdados da Coagulação Sanguínea , Transtornos da Coagulação Sanguínea , Trombose , Trombose Venosa , Doenças de von Willebrand , Transtornos da Coagulação Sanguínea/terapia , Criança , Hemorragia , Humanos , Trombose Venosa/etiologia , Doenças de von Willebrand/terapiaRESUMO
Prolonged cytopenias are a non-specific sign with a wide differential diagnosis. Among inherited disorders, cytopenias predisposing to leukemia require a timely and accurate diagnosis to ensure appropriate medical management, including adequate monitoring and stem cell transplantation prior to the development of leukemia. We aimed to define the types and prevalences of the genetic causes leading to persistent cytopenias in children. The study comprises children with persistent cytopenias, myelodysplastic syndrome, aplastic anemia, or suspected inherited bone marrow failure syndromes, who were referred for genetic evaluation from all pediatric hematology centers in Israel during 2016-2019. For variant detection, we used Sanger sequencing of commonly mutated genes and a custom-made targeted next-generation sequencing panel covering 226 genes known to be mutated in inherited cytopenias; the minority subsequently underwent whole exome sequencing. In total, 189 children with persistent cytopenias underwent a genetic evaluation. Pathogenic and likely pathogenic variants were identified in 59 patients (31.2%), including 47 with leukemia predisposing syndromes. Most of the latter (32, 68.1%) had inherited bone marrow failure syndromes, nine (19.1%) had inherited thrombocytopenia predisposing to leukemia, and three each (6.4%) had predisposition to myelodysplastic syndrome or congenital neutropenia. Twelve patients had cytopenias with no known leukemia predisposition, including nine children with inherited thrombocytopenia and three with congenital neutropenia. In summary, almost one third of 189 children referred with persistent cytopenias had an underlying inherited disorder; 79.7% of whom had a germline predisposition to leukemia. Precise diagnosis of children with cytopenias should direct follow-up and management programs and may positively impact disease outcome.
Assuntos
Anemia Aplástica , Leucemia , Síndromes Mielodisplásicas , Neutropenia , Trombocitopenia , Anemia Aplástica/genética , Criança , Síndrome Congênita de Insuficiência da Medula Óssea , Suscetibilidade a Doenças , Humanos , Síndromes Mielodisplásicas/diagnóstico , Síndromes Mielodisplásicas/genética , Neutropenia/congênito , Neutropenia/genética , Trombocitopenia/diagnóstico , Trombocitopenia/genéticaRESUMO
The transcription factor MEIS1 (myeloid ectotrophic insertion site 1) is crucial for the maintenance of hematopoietic stem cells and for megakaryopoiesis. Germline variants in MEIS1 are associated with restless-leg syndrome, but were not previously shown to cause cytopenias. This is the first report of a patient with congenital thrombocytopenia associated with a sequence variant in MEIS1, presenting with early onset severe thrombocytopenia and mild signs of bone marrow stress. Whole exome sequencing revealed a de novo monoallelic splice site variant in MEIS1, NM_002398.3:exon4:c.432 + 5 G > C, leading to a premature stop codon. We propose that heterozygous mutations in MEIS1 may cause congenital thrombocytopenia.
Assuntos
Trombocitopenia , Fatores de Transcrição , Regulação da Expressão Gênica , Humanos , Proteína Meis1/genética , Trombocitopenia/genética , Trombopoese/genética , Fatores de Transcrição/genéticaRESUMO
BACKGROUND: Inflammatory manifestations (IM) are well described in adult patients with myelodysplastic syndrome (MDS), but the presentation is highly variable and no standardized treatment exists. This phenomenon is rarely reported in children. As more pediatric patients are hematopoietic stem cell transplantation (HSCT) candidates, the role of anti-inflammatory treatment in relation to HSCT should be defined. PROCEDURE: Here, we report a series of five children from a tertiary center. We describe the clinical presentation, molecular findings, and treatment options. RESULTS: All patients presented with advanced MDS with blast percentages ranging 10-30%, all had severe IM. One patient had MDS secondary to severe congenital neutropenia, the other four patients had presumably primary MDS. All four were found to harbor a PTPN11 gene driver mutation, which is found in 35% of cases of juvenile myelomonocytic leukemia (JMML). The mutation was present in the myeloid lineage but not in T lymphocytes. Three had symptoms of Behcet's-like disease with trisomy 8 in their bone marrow. All patients were treated with anti-inflammatory medications (mainly systemic steroids) in an attempt to bring them to allogeneic HSCT in a better clinical condition. All demonstrated clinical improvement as well as regression in their MDS status post anti-inflammatory treatment. All have recovered from both MDS and their inflammatory symptoms post HSCT. CONCLUSION: Primary pediatric MDS with IM is driven in some cases by PTPN11 mutations, and might be on the clinical spectrum of JMML. Anti-inflammatory treatment may reverse MDS progression and improve the outcome of subsequent HSCT.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Leucemia Mielomonocítica Juvenil , Síndromes Mielodisplásicas , Criança , Humanos , Leucemia Mielomonocítica Juvenil/diagnóstico , Leucemia Mielomonocítica Juvenil/genética , Leucemia Mielomonocítica Juvenil/terapia , Mutação , Síndromes Mielodisplásicas/diagnóstico , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/terapia , Resultado do Tratamento , TrissomiaRESUMO
Detection of somatic mutations may help verify the diagnosis of myelodysplastic syndrome (MDS) in patients with persistent cytopenias or with MDS-predisposition syndromes, prior to the development of overt leukemia. However, the spectrum and consequences of acquired changes in paediatric patients have not been fully evaluated, and especially not in the context of an underlying syndrome. We incorporated a targeted next-generation-sequencing panel of 54 genes for the detection of somatic mutations in paediatric and young adult patients with inherited or acquired cytopenias. Sixty-five patients were included in this study, of whom 17 (26%) had somatic mutations. We detected somatic mutations in 20% of individuals with inherited MDS-predisposition syndromes, including in patients with severe congenital neutropenia and Fanconi anaemia, and with germline mutations in SAMD9L. Thirty-eight per cent of children with acquired cytopenias and suspected MDS had somatic changes, most commonly in genes related to signal transduction and transcription. Molecularly abnormal clones often preceded cytogenetic changes. Thus, routine performance of somatic panels can establish the diagnosis of MDS and determine the optimal timing of haematopoietic stem cell transplantation, prior to the development of leukaemia. In addition, performing somatic panels in patients with inherited MDS-predisposition syndromes may reveal their unique spectrum of acquired mutations.
Assuntos
Transformação Celular Neoplásica/genética , Predisposição Genética para Doença , Sequenciamento de Nucleotídeos em Larga Escala , Leucemia Mieloide Aguda/genética , Mutação , Síndromes Mielodisplásicas/genética , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
Gray platelet syndrome (GPS) is a rare recessive disorder caused by biallelic variants in NBEAL2 and characterized by bleeding symptoms, the absence of platelet α-granules, splenomegaly, and bone marrow (BM) fibrosis. Due to the rarity of GPS, it has been difficult to fully understand the pathogenic processes that lead to these clinical sequelae. To discern the spectrum of pathologic features, we performed a detailed clinical genotypic and phenotypic study of 47 patients with GPS and identified 32 new etiologic variants in NBEAL2. The GPS patient cohort exhibited known phenotypes, including macrothrombocytopenia, BM fibrosis, megakaryocyte emperipolesis of neutrophils, splenomegaly, and elevated serum vitamin B12 levels. Novel clinical phenotypes were also observed, including reduced leukocyte counts and increased presence of autoimmune disease and positive autoantibodies. There were widespread differences in the transcriptome and proteome of GPS platelets, neutrophils, monocytes, and CD4 lymphocytes. Proteins less abundant in these cells were enriched for constituents of granules, supporting a role for Nbeal2 in the function of these organelles across a wide range of blood cells. Proteomic analysis of GPS plasma showed increased levels of proteins associated with inflammation and immune response. One-quarter of plasma proteins increased in GPS are known to be synthesized outside of hematopoietic cells, predominantly in the liver. In summary, our data show that, in addition to the well-described platelet defects in GPS, there are immune defects. The abnormal immune cells may be the drivers of systemic abnormalities such as autoimmune disease.
Assuntos
Grânulos Citoplasmáticos/patologia , Heterogeneidade Genética , Síndrome da Plaqueta Cinza , Sistema Imunitário/patologia , Fenótipo , Biópsia , Proteínas Sanguíneas/genética , Estudos de Casos e Controles , Estudos de Coortes , Grânulos Citoplasmáticos/metabolismo , Diagnóstico Diferencial , Frequência do Gene , Estudos de Associação Genética , Síndrome da Plaqueta Cinza/classificação , Síndrome da Plaqueta Cinza/genética , Síndrome da Plaqueta Cinza/imunologia , Síndrome da Plaqueta Cinza/patologia , Humanos , Sistema Imunitário/fisiologia , Doenças do Sistema Imunitário/sangue , Doenças do Sistema Imunitário/diagnóstico , Doenças do Sistema Imunitário/genética , Doenças do Sistema Imunitário/patologia , MutaçãoRESUMO
Splenectomy is considered therapeutic in various non-malignant haematologic diseases. Adverse events - specifically infections and thromboembolism - are not extensively documented in the paediatric population, maintaining the concern over risks-versus-benefits of the procedure. We studied a cohort of paediatric haematology patients undergoing splenectomy between 1977 and 2015 to determine short- and long-term complications. We summarised all the patients of the haematology clinic in our major Israeli tertiary centre undergoing splenectomy for therapeutic reasons, capturing infectious and thromboembolic events. The data of 103 patients, comprising 1657 follow-up years, were analysed. The cohort included 33 patients with transfusion-dependent thalassaemia, seven with non-transfusion-dependent thalassaemia, four with sickle-thalassaemia, 41 with hereditary spherocytosis, and 18 with immune thrombocytopenia. Standard presplenectomy vaccinations were noted in most. No typical cases of overwhelming postsplenectomy infection (OPSI) were identified, nor were typical OPSI bacteria isolated. Thalassaemics with central lines were most prone to infection and thrombosis. Beyond this subgroup, thrombotic events were anecdotal. This is the largest study to date to comprehensively analyse infectious and thrombotic complications of childhood splenectomy for the treatment of haematologic diseases. The use of splenectomy appears to be a relatively safe therapeutic option in paediatric patients with proper preoperative vaccination and follow-up care; use of central venous lines or catheters increase the risk in thalassaemic patients and should be avoided if possible.
Assuntos
Doenças Hematológicas , Esplenectomia , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Seguimentos , Doenças Hematológicas/epidemiologia , Doenças Hematológicas/cirurgia , Humanos , Doença Iatrogênica/epidemiologia , Lactente , Masculino , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Estudos RetrospectivosRESUMO
BACKGROUND: The SRP54 (signal recognition protein 54) is a conserved component of the ribonucleoprotein complex that mediates cotranslational targeting and translocation of proteins to the endoplasmic reticulum. In 2017, mutations in the gene have been described as a cause of congenital neutropenia with or without pancreatic insufficiency, and since then, only limited cases were added to the literature. METHODS: Two patients with neutropenia underwent hematological, immunological, and genetic work-up, including lymphocyte phenotyping, immunoglobulins, and complement levels, antineutrophil and antinuclear antibodies, bone marrow FISH panel for myelodysplastic syndrome, whole-exome sequencing, and in silico proteomic analysis. RESULTS: Clinical findings in the two families revealed a wide spectrum of immunological and clinical manifestations, ranging from mild asymptomatic neutropenia during febrile illnesses to severe neutropenia and life-threatening infection requiring leg amputation. Immunological and hematological work-up showed isolated neutropenia with normal lymphocyte subpopulations, immunoglobulin and complement levels, and negative autoimmune tests. Bone marrow aspirations showed variability ranging from normal myelopoiesis to myeloid maturation arrest at the promyelocytic stage, with normal FISH panel for myelodysplastic syndrome. Genetic analysis identified a novel, de novo, in-frame deletion in the SRP54 gene, c.342-344delAAC, p.T115del. In silico proteomic analysis suggested impaired SRP54 protein function due to reduced GTP activity and stability. CONCLUSIONS: We describe congenital neutropenia with variable clinical presentation in novel mutation of the SRP54 gene.
Assuntos
Mutação , Neutropenia/congênito , Neutropenia/patologia , Partícula de Reconhecimento de Sinal/genética , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Neutropenia/genética , Neutropenia/metabolismo , Linhagem , Prognóstico , Proteômica , Sequenciamento do ExomaRESUMO
BACKGROUND: Essential thrombocythemia (ET) is rare in children, and pediatric guidelines are lacking. Therefore, we aimed to evaluate ET diagnosis and treatment in a pediatric cohort. PROCEDURE: Data of patients with ET from three hospitals were reviewed. Molecular diagnosis included JAK2V617F, CALR, and MPL mutations. Patients were evaluated for acquired von Willebrand syndrome (AVWS). Follow-up included clinical symptoms, adverse events, and treatment. RESULTS: Twelve children (median age: 8 years, range 1-14.5) were included. Mean lag period between the first documentation of thrombocytosis until ET diagnosis was 36 months. Six patients were positive for JAK2V617F and two for CALR mutations. In six of nine patients, AVWS was diagnosed. At diagnosis, only 33% of patients started therapy with aspirin (n = 4) and hydroxyurea (n = 2). In three of eight untreated patients, therapy was added during follow-up. The cohort was followed for a median of 32.5 months (range: 4-108 months). Clinical follow-up disclosed vascular complications in 4 of 12 patients (deep vein thrombosis, n = 1; transient ischemic attack, n = 3). Two females experienced excessive bleeding; both were diagnosed with AVWS. Neither leukemia nor myelofibrosis evolved in our cohort. CONCLUSION: Increased awareness to pediatric ET is warranted, as delayed diagnosis is common. Compared to adults, AVWS may be more prevalent among children with ET.
Assuntos
Calreticulina/genética , Janus Quinase 2/genética , Mutação , Receptores de Trombopoetina/genética , Trombocitemia Essencial/genética , Adolescente , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Lactente , Masculino , Estudos Retrospectivos , Trombocitemia Essencial/terapiaRESUMO
Fanconi anemia (FA), an inherited bone marrow failure (BMF) syndrome, caused by mutations in DNA repair genes, is characterized by congenital anomalies, aplastic anemia, high risk of malignancies and extreme sensitivity to alkylating agents. We aimed to study the clinical presentation, molecular diagnosis and genotype-phenotype correlation among patients with FA from the Israeli inherited BMF registry. Overall, 111 patients of Arab (57%) and Jewish (43%) descent were followed for a median of 15 years (range: 0.1-49); 63% were offspring of consanguineous parents. One-hundred patients (90%) had at least one congenital anomaly; over 80% of the patients developed bone marrow failure; 53% underwent hematopoietic stem-cell transplantation; 33% of the patients developed cancer; no significant association was found between hematopoietic stem-cell transplant and solid tumor development. Nearly 95% of the patients tested had confirmed mutations in the Fanconi genes FANCA (67%), FANCC (13%), FANCG (14%), FANCJ (3%) and FANCD1 (2%), including twenty novel mutations. Patients with FANCA mutations developed cancer at a significantly older age compared to patients with mutations in other Fanconi genes (mean 18.5 and 5.2 years, respectively, P=0.001); however, the overall survival did not depend on the causative gene. We hereby describe a large national cohort of patients with FA, the vast majority genetically diagnosed. Our results suggest an older age for cancer development in patients with FANCA mutations and no increased incidence of solid tumors following hematopoietic stem-cell transplant. Further studies are needed to guide individual treatment and follow-up programs.
Assuntos
Anemia de Fanconi , Anemia de Fanconi/genética , Proteína do Grupo de Complementação A da Anemia de Fanconi/genética , Proteína do Grupo de Complementação C da Anemia de Fanconi/genética , Estudos de Associação Genética , Humanos , Israel , MutaçãoAssuntos
Síndrome Linfoproliferativa Autoimune/diagnóstico , Plaquetas/patologia , Síndrome da Plaqueta Cinza/diagnóstico , Síndrome Linfoproliferativa Autoimune/sangue , Síndrome Linfoproliferativa Autoimune/patologia , Medula Óssea/patologia , Consanguinidade , Síndrome da Plaqueta Cinza/sangue , Síndrome da Plaqueta Cinza/patologia , Humanos , IrmãosRESUMO
BRCA1 is essential for repair of DNA double-strand breaks by homologous recombination, and hence for survival. Complete loss of its function is lethal during early embryonic development. Patients who are compound heterozygous for BRCA1 truncating mutations and missense alleles that retain some DNA repair capacity may survive, albeit with very high risk of early onset breast or ovarian cancer and features of Fanconi anemia. However, a mechanism enabling survival of patients homozygous for BRCA1 truncating mutations has not been described. We studied two unrelated families in which four children presented with multiple congenital anomalies and severe chromosomal fragility. One child developed T cell acute lymphocytic leukemia (ALL), and a second child developed neuroblastoma. Each of the four children was homozygous for a nonsense mutation in BRCA1 exon 11. Homozygosity for the nonsense mutations was viable thanks to the presence of a naturally occurring alternative splice donor in BRCA1 exon 11 that lies 5' of the mutations. The mutations did not affect the alternative splice site, but transcription from it produced an in-frame BRCA1 message with deletion of 3,309 bp. The translated BRCA1 protein was only 40% of normal length, but with intact N- and C-terminal sequences. These patients extend the range of BRCA1-related phenotypes and illustrate how naturally occurring alternative splicing can enable survival, albeit with severe consequences, of otherwise lethal genotypes of an essential gene.
Assuntos
Processamento Alternativo , Proteína BRCA1/genética , Neoplasias da Mama/genética , Códon sem Sentido , Homozigoto , Neoplasias Ovarianas/genética , Adolescente , Adulto , Neoplasias da Mama/patologia , Criança , Pré-Escolar , Feminino , Humanos , Neoplasias Ovarianas/patologia , LinhagemRESUMO
BACKGROUND: Most patients with anemia are diagnosed through clinical phenotype and basic laboratory testing. Nonetheless, in cases of rare congenital anemias, some patients remain undiagnosed despite undergoing an exhaustive workup. Genetic testing is complicated by the large number of genes involved in rare anemias and the similarities in the clinical presentation of the different syndromes. OBJECTIVE: We aimed to enhance the diagnosis of patients with congenital anemias by using targeted next-generation sequencing. METHODS: Genetic diagnosis was performed by gene capture followed by next-generation sequencing of 76 genes known to cause anemia syndromes. RESULTS: Genetic diagnosis was achieved in 13 out of 21 patients (62%). Six patients were diagnosed with pyruvate kinase deficiency, 4 with dehydrated hereditary stomatocytosis, 2 with sideroblastic anemia, and 1 with CDA type IV. Eight novel mutations were found. In 7 patients, the genetic diagnosis differed from the pretest presumed diagnosis. The mean lag time from presentation to diagnosis was over 13 years. CONCLUSIONS: Targeted next-generation sequencing led to an accurate diagnosis in over 60% of patients with rare anemias. These patients do not need further diagnostic workup. Earlier incorporation of this method into the workup of patients with congenital anemia may improve patients' care and enable genetic counseling.