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This study investigated from a longitudinal retrospective perspective what characterizes and predicts 6th graders (Mage = 12.95, SD = 0.27) with low (LMA) or high (HMA) math achievement concerning the development of early domain-specific and domain-general cognitive abilities. They were examined and compared to average achievers (n = 88) at four-time points from kindergarten (Mage = 6.58, SD = 0.36) to third grade (Mage = 9.53, SD = 0.33). The LMA (n = 27) or HMA (n = 41) children exhibited persistent multi-weakness and multi-strength profiles, respectively, present already prior to formal schooling. The cognitive profiles of the two groups, and their development, were mostly qualitatively similar, but there were also important qualitative differences. Logistic regression analyzes showed that superior verbal arithmetic, logical reasoning, and executive functions are vital for developing superior mathematical skills while inferior verbal arithmetic, logical reasoning, and spatial processing ability constitute unique potential risk factors for low mathematical skills.
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Logro , Cognición/fisiología , Función Ejecutiva/fisiología , Matemática , Procesamiento Espacial , Niño , Preescolar , Femenino , Humanos , Masculino , Solución de Problemas , Lectura , Estudios Retrospectivos , Instituciones AcadémicasRESUMEN
BACKGROUND: The aim was to examine the impact of lipopolysaccharide-induced systemic inflammation on expression of mRNA for cocaine- and amphetamine-regulated transcript (CART) and the thyrotropin receptor (TSHR) and its ligands in CNS areas of relevance for feeding controls and metabolism. Lipopolysaccharide effects on plasma levels of TSH and CART peptides were also examined. METHODS: Lipopolysaccharide (150-200 µg/mouse) was injected in C57BL/6J mice and tissue and plasma samples taken after 24 h. To establish if plasma increase in CART peptide levels were prostanoid dependent, indomethacin was given via the drinking water beginning 48 h prior to LPS. We evaluated mRNA expression for CART, TSHR, TSHß, and thyrostimulin in brain and pituitary extracts. Plasma levels of TSH, CARTp, and serum amyloid P component were analyzed by ELISA. RESULTS: Lipopolysaccharide suppressed TSHR mRNA expression in the arcuate nucleus and the pituitary. CART mRNA expression was reduced in the arcuate nucleus but elevated in the pituitary of mice treated with Lipopolysaccharide, whereas plasma TSH remained unchanged. Plasma CART peptide concentration increased after LPS treatment in a prostanoid-independent manner, and CART peptide levels correlated positively to degree of inflammation. CONCLUSIONS: Our findings suggest that central and peripheral CART is affected by acute inflammation. Considering the role of the arcuate nucleus in feeding controls, our data highlight TSHR and CART as putative neuroendocrine signaling components that respond to inflammation, perhaps to maintain weight and metabolic homeostasis during states of disease.
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Núcleo Arqueado del Hipotálamo/metabolismo , Inflamación/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Receptores de Tirotropina/metabolismo , Animales , Femenino , Lipopolisacáridos , Ratones Endogámicos C57BL , Hipófisis/metabolismo , ARN Mensajero/metabolismo , Distribución Aleatoria , Pérdida de PesoRESUMEN
To date, few studies have tried to pinpoint the mechanisms supporting children's skills in science. This study investigated to what extent logical reasoning, spatial processing, and working memory, tapped at age 9-10 years, are predictive of physics skills at age 12-13 years. The study used a sample of 81 children (37 girls). Measures of arithmetic calculation and reading comprehension were also included in the study. The multiple regression model accounted for 24% of the variation in physics achievement. The model showed that spatial processing (4.6%) and verbal working memory (4.5%) accounted for a similar amount of unique variance, while logical reasoning accounted for 5.7% variance. The measures of arithmetic calculation and reading comprehension did not account for any unique variance. Nine percent of the accounted variance was shared variance. The results demonstrate that physics is a multivariate discipline that draws upon numerous cognitive resources. Logical reasoning ability is a key component in order for children to learn about abstract physics facts, concepts, theories, and applying complex scientific methods. Spatial processing is important as it may sub-serve the assembly of diverse sources of visual-spatial information into a spatial-schematic image. The working memory system provides a flexible and efficient mental workspace that can supervise, coordinate, and execute processes involved in physics problem-solving.
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Hyperdiploidy, i.e. gain of whole chromosomes, is one of the most common genetic features of childhood acute lymphoblastic leukemia (ALL), but its pathogenetic impact is poorly understood. Here, we report a proteogenomic analysis on matched datasets from genomic profiling, RNA-sequencing, and mass spectrometry-based analysis of >8,000 genes and proteins as well as Hi-C of primary patient samples from hyperdiploid and ETV6/RUNX1-positive pediatric ALL. We show that CTCF and cohesin, which are master regulators of chromatin architecture, display low expression in hyperdiploid ALL. In line with this, a general genome-wide dysregulation of gene expression in relation to topologically associating domain (TAD) borders were seen in the hyperdiploid group. Furthermore, Hi-C of a limited number of hyperdiploid childhood ALL cases revealed that 2/4 cases displayed a clear loss of TAD boundary strength and 3/4 showed reduced insulation at TAD borders, with putative leukemogenic effects.
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Regulación Leucémica de la Expresión Génica , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Transcripción Genética , Adolescente , Aneuploidia , Factor de Unión a CCCTC/genética , Proteínas de Ciclo Celular/genética , Niño , Preescolar , Cromatina/genética , Proteínas Cromosómicas no Histona/genética , Aberraciones Cromosómicas , Subunidad alfa 2 del Factor de Unión al Sitio Principal/genética , Femenino , Dosificación de Gen , Perfilación de la Expresión Génica , Genoma Humano , Estudio de Asociación del Genoma Completo , Humanos , Lactante , Recién Nacido , Masculino , Proteogenómica/métodos , Proteoma/genética , Proteínas Proto-Oncogénicas c-ets/genética , Proteínas Represoras/genética , Análisis de Secuencia de ARN , Cohesinas , Proteína ETS de Variante de Translocación 6RESUMEN
Most B cell precursor acute lymphoblastic leukemia (BCP ALL) can be classified into known major genetic subtypes, while a substantial proportion of BCP ALL remains poorly characterized in relation to its underlying genomic abnormalities. We therefore initiated a large-scale international study to reanalyze and delineate the transcriptome landscape of 1,223 BCP ALL cases using RNA sequencing. Fourteen BCP ALL gene expression subgroups (G1 to G14) were identified. Apart from extending eight previously described subgroups (G1 to G8 associated with MEF2D fusions, TCF3-PBX1 fusions, ETV6-RUNX1-positive/ETV6-RUNX1-like, DUX4 fusions, ZNF384 fusions, BCR-ABL1/Ph-like, high hyperdiploidy, and KMT2A fusions), we defined six additional gene expression subgroups: G9 was associated with both PAX5 and CRLF2 fusions; G10 and G11 with mutations in PAX5 (p.P80R) and IKZF1 (p.N159Y), respectively; G12 with IGH-CEBPE fusion and mutations in ZEB2 (p.H1038R); and G13 and G14 with TCF3/4-HLF and NUTM1 fusions, respectively. In pediatric BCP ALL, subgroups G2 to G5 and G7 (51 to 65/67 chromosomes) were associated with low-risk, G7 (with ≤50 chromosomes) and G9 were intermediate-risk, whereas G1, G6, and G8 were defined as high-risk subgroups. In adult BCP ALL, G1, G2, G6, and G8 were associated with high risk, while G4, G5, and G7 had relatively favorable outcomes. This large-scale transcriptome sequence analysis of BCP ALL revealed distinct molecular subgroups that reflect discrete pathways of BCP ALL, informing disease classification and prognostic stratification. The combined results strongly advocate that RNA sequencing be introduced into the clinical diagnostic workup of BCP ALL.
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Leucemia-Linfoma Linfoblástico de Células Precursoras B/clasificación , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Transcriptoma , Adulto , Niño , Bases de Datos de Ácidos Nucleicos , Femenino , Humanos , Masculino , Modelos Genéticos , Mutación , Fusión de Oncogenes , Proteínas de Fusión Oncogénica/genética , Pronóstico , Análisis de Secuencia de ARNRESUMEN
Single nucleotide polymorphism array (SNP-A) analyses are increasingly being introduced in routine genetic diagnostics of acute lymphoblastic leukemia (ALL). Despite this, only few studies that have compared the diagnostic value of SNP-A with conventional chromosome banding have been published. We here report such a comparison of 296 ALL cases, the largest series to date. Only genomic imbalances >5 Mb and microdeletions targeting the BTG1, CDKN2A/B, EBF1, ERG, ETV6, IKZF1, PAX5, and RB1 genes and the pseudoautosomal region 1 (PAR1) were ascertained, in agreement with recent guidelines. Of 36 T-cell ALL cases, the karyotypes of 24 cases (67%) were revised by SNP-A analyses that either revealed additional imbalances >5 Mb or better characterized the changes found by G-banding. Of 260 B-cell precursor (BCP) ALL cases, SNP-A analyses identified additional copy number alterations, including the above-mentioned microdeletions, or better characterized the imbalances found by G-banding in 236 (91%) cases. Furthermore, the cytogenetic subtype classification of 41/260 (16%) BCP ALL cases was revised based on the SNP-A findings. Of the subtype revisions, 12/41 (29%) had clinical implications as regards risk stratifying cytogenetic groups or genotype-specific minimal residual disease stratification. We conclude that SNP-A analyses dramatically improve the cytogenetic characterization of both T-cell and BCP ALL and also provide important information pertinent to risk stratification of BCP ALL.
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Polimorfismo de Nucleótido Simple/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiología , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adolescente , Niño , Preescolar , Estudios de Cohortes , Análisis Citogenético , Humanos , Lactante , Recién Nacido , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnósticoAsunto(s)
Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Disomía Uniparental/genética , Alelos , Aberraciones Cromosómicas , Biología Computacional/métodos , Bases de Datos Genéticas , Variación Genética , Genotipo , Humanos , Polimorfismo de Nucleótido Simple , Leucemia-Linfoma Linfoblástico de Células Precursoras B/diagnóstico , Secuenciación del ExomaRESUMEN
High-throughput sequencing was applied to investigate the mutation/methylation patterns on 1q and gene expression profiles in pediatric B-cell precursor acute lymphoblastic leukemia (BCP ALL) with/without (w/wo) dup(1q). Sequencing of the breakpoint regions and all exons on 1q in seven dup(1q)-positive cases revealed non-synonymous somatic single nucleotide variants (SNVs) in BLZF1, FMN2, KCNT2, LCE1C, NES, and PARP1. Deep sequencing of these in a validation cohort w (n = 17)/wo (n = 94) dup(1q) revealed similar SNV frequencies in the two groups (47% vs. 35%; P = 0.42). Only 0.6% of the 36,259 CpGs on 1q were differentially methylated between cases w (n = 14)/wo (n = 13) dup(1q). RNA sequencing of high hyperdiploid (HeH) and t(1;19)(q23;p13)-positive cases w (n = 14)/wo (n = 52) dup(1q) identified 252 and 424 differentially expressed genes, respectively; only seven overlapped. Of the overexpressed genes in the HeH and t(1;19) groups, 23 and 31%, respectively, mapped to 1q; 60-80% of these encode nucleic acid/protein binding factors or proteins with catalytic activity. We conclude that the pathogenetically important consequence of dup(1q) in BCP ALL is a gene-dosage effect, with the deregulated genes differing between genetic subtypes, but involving similar molecular functions, biological processes, and protein classes.
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Metilación de ADN/genética , Polimorfismo de Nucleótido Simple/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Transcriptoma/genética , Adolescente , Linfocitos B/fisiología , Niño , Preescolar , Estudios de Cohortes , Diploidia , Exones/genética , Femenino , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Humanos , Lactante , Masculino , Análisis de Secuencia de ARN/métodosRESUMEN
A modified pathways to mathematics model was used to examine the cognitive mechanisms underlying arithmetic skills in third graders. A total of 269 children were assessed on tasks tapping the four pathways and arithmetic skills. A path analysis showed that symbolic number processing was directly supported by the linguistic and approximate quantitative pathways. The direct contribution from the four pathways to arithmetic proficiency varied; the linguistic pathway supported single-digit arithmetic and word problem solving, whereas the approximate quantitative pathway supported only multi-digit calculation. The spatial processing and verbal working memory pathways supported only arithmetic word problem solving. The notion of hierarchical levels of arithmetic was supported by the results, and the different levels were supported by different constellations of pathways. However, the strongest support to the hierarchical levels of arithmetic were provided by the proximal arithmetic skills.
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Cognición/fisiología , Matemática , Solución de Problemas/fisiología , Niño , Femenino , Humanos , Masculino , Memoria a Corto Plazo/fisiología , Procesamiento Espacial/fisiologíaRESUMEN
BACKGROUND: Developing sufficient mathematical skills is a prerequisite to function adequately in society today. Given this, an important task is to increase our understanding regarding the cognitive mechanisms underlying young people's acquisition of early number skills and formal mathematical knowledge. AIMS: The purpose was to examine whether the pathways to mathematics model provides a valid account of the cognitive mechanisms underlying symbolic-number processing and mathematics in adolescents. The pathways model states that the three pathways should provide independent support to symbolic-number skill. Each pathway's unique contribution to formal mathematics varies depending on the complexity and demand of the tasks. SAMPLE: The study used a sample of 114 adolescents (71 girls). Their mean age was 14.60 years (SD = 1.00). METHODS: The adolescents were assessed on tests tapping the three pathways and general cognitive abilities (e.g., working memory). A structural equation path analysis was computed. RESULTS: Symbolic-number comparison was predicted by the linguistic pathway, the quantitative pathway, and processing speed. The linguistic pathway, quantitative pathways, and symbolic-number comparison predicted arithmetic fact retrieval. The linguistic pathway, working memory, visual analogies, and symbolic-number comparison predicted percentage calculation. CONCLUSIONS: There are both similarities and differences in the cognitive mechanisms underlying arithmetic fact retrieval and percentage calculation in adolescents. Adolescents' symbolic-number processing, arithmetic fact retrieval, and percentage calculation continue to rely on the linguistic pathways, whereas the reliance upon the spatial pathway has ceased. The reliance upon the quantitative pathway varies depending on the task.
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Lenguaje , Conceptos Matemáticos , Matemática/educación , Procesos Mentales/fisiología , Modelos Psicológicos , Adolescente , Femenino , Humanos , MasculinoRESUMEN
Global management of wetlands to suppress greenhouse gas (GHG) emissions, facilitate carbon (C) sequestration, and reduce atmospheric CO2 concentrations while simultaneously promoting agricultural gains is paramount. However, studies that relate variability in CO2 and CH4 emissions at large spatial scales are limited. We investigated three-year emissions of soil CO2 and CH4 from the primary wetland types of the Liaohe Delta, China, by focusing on a total wetland area of 3287 km2. One percent is Suaeda salsa, 24% is Phragmites australis, and 75% is rice. While S. salsa wetlands are under somewhat natural tidal influence, P. australis and rice are managed hydrologically for paper and food, respectively. Total C emissions from CO2 and CH4 from these wetland soils were 2.9 Tg C/year, ranging from 2.5 to 3.3 Tg C/year depending on the year assessed. Primary emissions were from CO2 (~98%). Photosynthetic uptake of CO2 would mitigate most of the soil CO2 emissions, but CH4 emissions would persist. Overall, CH4 fluxes were high when soil temperatures were >18°C and pore water salinity <18 PSU. CH4 emissions from rice habitat alone in the Liaohe Delta represent 0.2% of CH4 carbon emissions globally from rice. With such a large area and interannual sensitivity in soil GHG fluxes, management practices in the Delta and similar wetlands around the world have the potential not only to influence local C budgeting, but also to influence global biogeochemical cycling.
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Dióxido de Carbono/análisis , Metano/análisis , Suelo/química , Humedales , Carbono/análisis , China , Monitoreo del Ambiente/métodos , Estaciones del AñoRESUMEN
Fusion genes are potent driver mutations in cancer. In this study, we delineate the fusion gene landscape in a consecutive series of 195 paediatric B-cell precursor acute lymphoblastic leukaemia (BCP ALL). Using RNA sequencing, we find in-frame fusion genes in 127 (65%) cases, including 27 novel fusions. We describe a subtype characterized by recurrent IGH-DUX4 or ERG-DUX4 fusions, representing 4% of cases, leading to overexpression of DUX4 and frequently co-occurring with intragenic ERG deletions. Furthermore, we identify a subtype characterized by an ETV6-RUNX1-like gene-expression profile and coexisting ETV6 and IKZF1 alterations. Thus, this study provides a detailed overview of fusion genes in paediatric BCP ALL and adds new pathogenetic insights, which may improve risk stratification and provide therapeutic options for this disease.
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Reordenamiento Génico/genética , Proteínas de Homeodominio/genética , Proteínas de Fusión Oncogénica/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Empalme Alternativo/genética , Niño , Rotura Cromosómica , Análisis por Conglomerados , Estudios de Cohortes , Análisis Mutacional de ADN , Regulación Neoplásica de la Expresión Génica , Redes Reguladoras de Genes , Humanos , Análisis de Componente PrincipalRESUMEN
To identify copy number alterations (CNAs) in pediatric B-cell precursor acute lymphoblastic leukemia (BCP ALL), array comparative genomic hybridization was performed on 50 cases; detected CNAs were validated in a cohort of 191 cases analyzed by single nucleotide polymorphism arrays. Apart from CNAs involving leukemia-associated genes, recurrent deletions targeting genes not previously implicated in BCP ALL, e.g. INIP, IRF1 and PDE4B, were identified. Deletions of the DNA repair gene INIP were exclusively found in cases with t(12;21), and deletions of SH2B3 were associated with intrachromosomal amplification of chromosome 21 (p < 0.001). A majority of BTLA deletions (7/11; 64%) affected samples with gain of 21q chromosome material, suggesting that BTLA deletions are associated with both germline and somatic gain of chromosome 21. In cases without known risk-associated cytogenetic markers, CNAs associated with adverse prognosis were identified in 50% (10/20), indicating that a majority of these cases could be assigned to distinct genetic subtypes.
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Eliminación de Gen , Dosificación de Gen , Regulación Neoplásica de la Expresión Génica , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patología , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Transformación Celular Neoplásica/genética , Niño , Preescolar , Aberraciones Cromosómicas , Hibridación Genómica Comparativa , Biología Computacional/métodos , Variaciones en el Número de Copia de ADN , Progresión de la Enfermedad , Epigénesis Genética , Femenino , Perfilación de la Expresión Génica , Humanos , Lactante , Recién Nacido , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/mortalidad , RecurrenciaRESUMEN
Cytogenetic analyses of a consecutive series of 67 paediatric (median age 8 years; range 0-17) de novo acute myeloid leukaemia (AML) patients revealed aberrations in 55 (82%) cases. The most common subgroups were KMT2A rearrangement (29%), normal karyotype (15%), RUNX1-RUNX1T1 (10%), deletions of 5q, 7q and/or 17p (9%), myeloid leukaemia associated with Down syndrome (7%), PML-RARA (7%) and CBFB-MYH11 (5%). Single nucleotide polymorphism array (SNP-A) analysis and exon sequencing of 100 genes, performed in 52 and 40 cases, respectively (39 overlapping), revealed ≥1 aberration in 89%; when adding cytogenetic data, this frequency increased to 98%. Uniparental isodisomies (UPIDs) were detected in 13% and copy number aberrations (CNAs) in 63% (median 2/case); three UPIDs and 22 CNAs were recurrent. Twenty-two genes were targeted by focal CNAs, including AEBP2 and PHF6 deletions and genes involved in AML-associated gene fusions. Deep sequencing identified mutations in 65% of cases (median 1/case). In total, 60 mutations were found in 30 genes, primarily those encoding signalling proteins (47%), transcription factors (25%), or epigenetic modifiers (13%). Twelve genes (BCOR, CEBPA, FLT3, GATA1, KIT, KRAS, NOTCH1, NPM1, NRAS, PTPN11, SMC3 and TP53) were recurrently mutated. We conclude that SNP-A and deep sequencing analyses complement the cytogenetic diagnosis of paediatric AML.
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Análisis Citogenético/métodos , Exones/genética , Leucemia Mieloide Aguda/genética , Polimorfismo de Nucleótido Simple , Adolescente , Niño , Preescolar , Humanos , Lactante , Recién Nacido , Leucemia Mieloide Aguda/diagnóstico , Mutación , Nucleofosmina , Análisis de Secuencia de ADNRESUMEN
Single nucleotide polymorphism (SNP) arrays are increasingly being used in clinical routine for genetic analysis of pediatric B-cell precursor acute lymphoblastic leukemias (BCP ALL). Because constitutional DNA is not readily available as a control at the time of diagnosis, it is important to be able to distinguish between acquired and constitutional aberrations in a diagnostic setting. In the present study we focused on uniparental isodisomies (UPIDs). SNP array analyses of 143 pediatric and 38 adult B-cell precursor acute lymphoblastic leukemias and matched remission samples revealed acquired whole chromosome or segmental UPIDs (wUPIDs, sUPIDs) in 32 cases (18%), without any age- or gender-related frequency differences. Acquired sUPIDs were larger than the constitutional ones (mean 35.3 Mb vs. 10.7 Mb; P < 0.0001) and were more often terminally located in the chromosomes (69% vs. 4.5%; P < 0.0001). Chromosomes 3, 5, and 9 were most often involved in acquired wUPIDs, whilst recurrent acquired sUPIDs targeted 6p, 9p, 9q, and 14q. The majority (56%) of sUPID9p was associated with homozygous CDKN2A deletions. In pediatric ALL, all wUPIDs were found in high hyperdiploid (51-67 chromosomes) cases and an extended analysis, also including unmatched diagnostic samples, revealed a higher frequency of wUPID-positivity in higher modal number (56-67 chromosomes) than in lower modal number (51-55 chromosomes) high hyperdiploid cases (34% vs. 11%; P = 0.04), suggesting different underlying mechanisms of formation of these subtypes of high hyperdiploidy. © 2016 Wiley Periodicals, Inc.
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Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Adulto , Niño , HumanosRESUMEN
Developmental Dyscalculia (DD) has long been thought to be a monolithic learning disorder that can be attributed to a specific neurocognitive dysfunction. However, recent research has increasingly recognized the heterogeneity of DD, where DD can be differentiated into subtypes in which the underlying cognitive deficits and neural dysfunctions may differ. The aim was to further understand the heterogeneity of developmental dyscalculia (DD) from a cognitive psychological perspective. Utilizing four children (8-9 year-old) we administered a comprehensive cognitive test battery that shed light on the cognitive-behavioral profile of each child. The children were compared against norm groups of aged-matched peers. Performance was then contrasted against predominant hypotheses of DD, which would also give insight into candidate neurocognitive correlates. Despite showing similar mathematical deficits, these children showed remarkable interindividual variability regarding cognitive profile and deficits. Two cases were consistent with the approximate number system deficit account and also the general magnitude-processing deficit account. These cases showed indications of having domain-general deficits as well. One case had an access deficit in combination with a general cognitive deficit. One case suffered from general cognitive deficits only. The results showed that DD cannot be attributed to a single explanatory factor. These findings support a multiple deficits account of DD and suggest that some cases have multiple deficits, whereas other cases have a single deficit. We discuss a previously proposed distinction between primary DD and secondary DD, and suggest hypotheses of dysfunctional neurocognitive correlates responsible for the displayed deficits.
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PURPOSE: To investigate the genetic and epigenetic landscape of hypodiploid (<45 chromosomes) acute lymphoblastic leukemia (ALL). METHODS: Single nucleotide polymorphism array, whole exome sequencing, RNA sequencing, and methylation array analyses were performed on eleven hypodiploid ALL cases. RESULTS: In line with previous studies, mutations in IKZF3 and FLT3 were detected in near-haploid (25-30 chromosomes) cases. Low hypodiploidy (31-39 chromosomes) was associated with somatic TP53 mutations. Notably, mutations of this gene were also found in 3/3 high hypodiploid (40-44 chromosomes) cases, suggesting that the mutational patterns are similar in low hypodiploid and high hypodiploid ALL. The high hypodiploid ALLs frequently displayed substantial cell-to-cell variability in chromosomal content, indicative of chromosomal instability; a rare phenomenon in ALL. Gene expression analysis showed that genes on heterodisomic chromosomes were more highly expressed in hypodiploid cases. Cases clustered according to hypodiploid subtype in the unsupervised methylation analyses, but there was no association between chromosomal copy number and methylation levels. A comparison between samples obtained at diagnosis and relapse showed that the relapse did not arise from the major diagnostic clone in 3/4 cases. CONCLUSIONS: Taken together, our data support the conclusion that near-haploid and low hypodiploid ALL are different with regard to mutational profiles and also suggest that ALL cases with high hypodiploidy may harbor chromosomal instability.
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Aneuploidia , Epigénesis Genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Transcriptoma/genética , Cariotipo Anormal , Adolescente , Adulto , Anciano , Niño , Preescolar , Análisis Mutacional de ADN , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Hibridación Fluorescente in Situ , Lactante , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
High hyperdiploid (51-67 chromosomes) acute lymphoblastic leukemia (ALL) is one of the most common childhood malignancies, comprising 30% of all pediatric B cell-precursor ALL. Its characteristic genetic feature is the nonrandom gain of chromosomes X, 4, 6, 10, 14, 17, 18 and 21, with individual trisomies or tetrasomies being seen in over 75% of cases, but the pathogenesis remains poorly understood. We performed whole-genome sequencing (WGS) (n = 16) and/or whole-exome sequencing (WES) (n = 39) of diagnostic and remission samples from 51 cases of high hyperdiploid ALL to further define the genomic landscape of this malignancy. The majority of cases showed involvement of the RTK-RAS pathway and of histone modifiers. No recurrent fusion gene-forming rearrangement was found, and an analysis of mutations on trisomic chromosomes indicated that the chromosomal gains were early events, strengthening the notion that the high hyperdiploid pattern is the main driver event in this common pediatric malignancy.
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Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adolescente , Niño , Preescolar , Diploidia , Femenino , Genoma Humano , Humanos , Lactante , Masculino , Mutación , Polimorfismo de Nucleótido SimpleRESUMEN
Paediatric B-cell precursor acute lymphoblastic leukaemias (BCP ALL) with IKZF1 deletions (∆IKZF1) are associated with a poor outcome. However, there are conflicting data as to whether ∆IKZF1 is an independent risk factor if minimal residual disease (MRD) and other copy number alterations also are taken into account. We investigated 334 paediatric BCP ALL, diagnosed 1992-2013 and treated according to Nordic Society for Paediatric Haematology and Oncology ALL protocols, with known IKZF1 status based on either single nucleotide polymorphism array (N = 218) or multiplex ligation-dependent probe amplification (N = 116) analyses. ∆IKZF1, found in 15%, was associated with inferior 10-year probabilities of event-free (60% vs. 83%; P < 0·001) and overall survival (pOS; 73% vs. 89%; P = 0·001). Adjusting for known risk factors, including white blood cell (WBC) count and MRD, ∆IKZF1 was the strongest independent factor for relapse and death. ∆IKZF1 was present in 27% of cases with non-informative cytogenetics ('BCP-other') and a poor 10-year pOS was particularly pronounced in this group (58% vs. 90%; P < 0·001). Importantly, neither MRD nor WBC count predicted events in the ∆IKZF1-positive cases. Co-occurrence of pseudoautosomal region 1 (PAR1) deletions in Xp22.33/Yp11.32 (P2RY8-CRLF2) and ∆IKZF1 increased the risk of relapse (75% vs. 30% for cases with only ∆IKZF1; P = 0·045), indicating that BCP-other ALL with both P2RY8-CRLF2 and ∆IKZF1 constitutes a particularly high-risk group.