RESUMO
Changes in gene dosage are a major driver of cancer, known to be caused by a finite, but increasingly well annotated, repertoire of mutational mechanisms. This can potentially generate correlated copy-number alterations across hundreds of linked genes, as exemplified by the 2% of childhood acute lymphoblastic leukaemia (ALL) with recurrent amplification of megabase regions of chromosome 21 (iAMP21). We used genomic, cytogenetic and transcriptional analysis, coupled with novel bioinformatic approaches, to reconstruct the evolution of iAMP21 ALL. Here we show that individuals born with the rare constitutional Robertsonian translocation between chromosomes 15 and 21, rob(15;21)(q10;q10)c, have approximately 2,700-fold increased risk of developing iAMP21 ALL compared to the general population. In such cases, amplification is initiated by a chromothripsis event involving both sister chromatids of the Robertsonian chromosome, a novel mechanism for cancer predisposition. In sporadic iAMP21, breakage-fusion-bridge cycles are typically the initiating event, often followed by chromothripsis. In both sporadic and rob(15;21)c-associated iAMP21, the final stages frequently involve duplications of the entire abnormal chromosome. The end-product is a derivative of chromosome 21 or the rob(15;21)c chromosome with gene dosage optimized for leukaemic potential, showing constrained copy-number levels over multiple linked genes. Thus, dicentric chromosomes may be an important precipitant of chromothripsis, as we show rob(15;21)c to be constitutionally dicentric and breakage-fusion-bridge cycles generate dicentric chromosomes somatically. Furthermore, our data illustrate that several cancer-specific mutational processes, applied sequentially, can coordinate to fashion copy-number profiles over large genomic scales, incrementally refining the fitness benefits of aggregated gene dosage changes.
Assuntos
Aberrações Cromossômicas , Cromossomos Humanos Par 21/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Cromátides/genética , Quebra Cromossômica , Cromossomos Humanos Par 15/genética , Variações do Número de Cópias de DNA/genética , Humanos , Recombinação Genética/genética , Translocação Genética/genéticaRESUMO
I am a single woman of a certain age. I have Alzheimer's disease and I live alone without a carer. I manage as best I can, but I am often in terror of inevitable future deterioration.
Assuntos
Doença de Alzheimer , Grupo Associado , Apoio Social , Serviços de Saúde/provisão & distribuição , Humanos , Identificação SocialRESUMO
Intrachromosomal amplification of chromosome 21 (iAMP21) defines a distinct subgroup of childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL) that has a dismal outcome when treated with standard therapy. For improved diagnosis and risk stratification, the initiating genetic events need to be elucidated. To investigate the genetic basis of BCP-ALL, genomes of 94 iAMP21 patients were interrogated by arrays, FISH, and multiplex ligation-dependent probe amplification. Most copy number alterations targeted chromosome 21, reinforcing the complexity of this chromosome. The common region of amplification on chromosome 21 was refined to a 5.1-mb region that included RUNX1, miR-802, and genes mapping to the Down syndrome critical region. Recurrent abnormalities affecting genes in key pathways were identified: IKZF1 (22%), CDKN2A/B (17%), PAX5 (8%), ETV6 (19%), and RB1 (37%). Investigation of clonal architecture provided evidence that these abnormalities, and P2RY8-CRLF2, were secondary to chromosome 21 rearrangements. Patient outcome was uniformly poor with standard therapy irrespective of the presence or absence of these changes. This study has provided evidence that chromosome 21 instability is the only anomaly among those so far investigated that is common to all iAMP21 patients, and therefore the initiating event is likely to be found among the complex structural rearrangements of this abnormal chromosome.
Assuntos
Cromossomos Humanos Par 21 , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Adolescente , Adulto , Criança , Pré-Escolar , Aberrações Cromossômicas , Estudos de Coortes , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Feminino , Dosagem de Genes , Humanos , Janus Quinases/genética , Masculino , Mutação , Adulto JovemRESUMO
OBJECTIVES: This study examined the relation of multiple aspects of the home food environment to dietary intake and body weight among overweight and obese children in southern Appalachia. METHODS: The study used baseline data from a cluster-randomized controlled trial, Parent-Led Activity and Nutrition for Healthy Living, evaluating a parent-mediated approach to treating child overweight and obesity in the primary care setting in southern Appalachia. Sixty-seven children ages 5 to 11 years were recruited from four primary care clinics. Multiple linear regression was used to estimate the relation between multiple aspects of the home food environment to dietary intake (fruit and vegetable intake, fat and sweets intake), and standardized body mass index (zBMI), adjusted for baseline family characteristics (education, smoking status during the past month, BMI) and child characteristics (sex, age, Medicaid/TennCare). RESULTS: Findings showed greater parental restriction and pressure in feeding were associated with greater fruit and vegetable intake in children (ß = 0.33, ß = 0.30, respectively; both P < 0.05). The availability of chips and sweets in a child's home and parental inappropriate modeling of eating were associated with an increased risk for consumption of fats and sweets by children (ß = 0.47, ß = 0.54, respectively; both P < 0.01). Parental monitoring of the child's eating was associated with a reduced risk for fat and sweets intake (ß = -0.24; P < 0.01). Finally, parental responsibility for feeding the child was associated with lower zBMI (ß = -0.20; P < 0.05). CONCLUSIONS: The home food environment, including food availability and parenting behaviors, was associated with overweight and obese children's dietary intake and weight. This study adds to evidence suggesting that programs aimed at improving overweight and obese children's eating patterns may target both aspects of the physical home environment and parental behaviors surrounding eating.
Assuntos
Dieta , Sobrepeso/etiologia , Poder Familiar , Adulto , Região dos Apalaches , Atitude Frente a Saúde , Índice de Massa Corporal , Criança , Pré-Escolar , Estudos Transversais , Inquéritos sobre Dietas , Feminino , Humanos , Modelos Lineares , Masculino , Comportamento Materno , Obesidade/etiologia , Relações Pais-Filho , Comportamento Paterno , Autorrelato , Fatores SocioeconômicosRESUMO
School-based efforts to promote physical activity and healthier eating are a potentially effective approach to decreasing child obesity in rural populations. This article describes follow-up data on student activity and eating behaviors 4 years after implementation of the Winning with Wellness obesity prevention initiative. This project was based on the Centers for Disease Control and Prevention's coordinated school health model and used a community-based participatory research approach to address health behaviors in rural Appalachian elementary students. Results suggest significant increases in daily pedometer steps and healthier food selections by students as well as teacher support for continued health promotion efforts.
Assuntos
Exercício Físico , Comportamento Alimentar , Promoção da Saúde , População Rural , Actigrafia , Região dos Apalaches , Criança , Coleta de Dados , Dieta , Feminino , Humanos , Masculino , Obesidade/prevenção & controle , Projetos Piloto , Desenvolvimento de Programas , EstudantesRESUMO
OBJECTIVE: The prevalence of childhood overweight and obesity in southern Appalachia is among the highest in the United States (US). Primary care providers are in a unique position to address the problem; however, little is known about attitudes and practices in these settings. METHODS: A 61-item healthcare provider questionnaire assessing current practices, attitudes, perceived barriers, and skill levels in managing childhood overweight and obesity was distributed to physicians in four primary care clinics. Questionnaires were obtained from 36 physicians. RESULTS: Physicians' practices to address childhood overweight and obesity were limited, despite the fact that most physicians shared the attitude that childhood overweight and obesity need attention. While 71% of physicians reported talking about eating and physical activity habits with parents of overweight or obese children, only 19% reported giving these parents the tools they needed to make changes. Approximately 42% determined the parents' readiness to make small changes for their overweight or obese children. Physicians' self-perceived skill level in managing childhood overweight and obesity was found to be a key factor for childhood overweight- and obesity- related practices. CONCLUSION: Primary care physicians in southern Appalachia currently play a limited role in the prevention or intervention of childhood overweight and obesity. Training physicians to improve their skills in managing childhood overweight and obesity may lead to an improvement in practice.
Assuntos
Atitude do Pessoal de Saúde , Obesidade/prevenção & controle , Sobrepeso/prevenção & controle , Papel do Médico , Médicos de Atenção Primária/normas , Atenção Primária à Saúde/métodos , Adulto , Região dos Apalaches/epidemiologia , Criança , Competência Clínica , Feminino , Humanos , Masculino , Obesidade/epidemiologia , Sobrepeso/epidemiologia , Prevalência , Inquéritos e QuestionáriosRESUMO
This article provides nurses with a simple structure to aid effective communication. It explains how one trust implemented the situation-background-assessment-recommendation (SBAR) structure to improve patient handover, and outlines the benefits for nurses and patients.
Assuntos
Continuidade da Assistência ao Paciente , Relações Interprofissionais , Administração dos Cuidados ao Paciente , Sistemas de Alerta , Gestão de Riscos , Comunicação , Inglaterra , Humanos , Modelos Organizacionais , Recursos Humanos de Enfermagem Hospitalar , Relações Médico-EnfermeiroRESUMO
The cell line ARH77 is derived from a patient with plasma cell leukemia and has a complex and continually evolving karyotype. It is frequently used in biological studies of myeloma and plasma cell leukemia, so accurate characterization of the genome is valuable. Here we present a detailed cytogenetic investigation using G-banding and multicolor fluorescence in situ hybridization (M-FISH) in association with assessment of copy number alterations (CNAs) throughout the genome using array-based comparative genomic hybridization (aCGH). In addition to providing an accurate description of the karyotype, this complementary approach highlighted the relative merits of the individual techniques. Conventional cytogenetics and M-FISH indicated the location and types of the major chromosomal changes, whether balanced or unbalanced, and at the same time demonstrated the level of karyotypic evolution between cells. The aCGH profiles reflected the unbalanced chromosomal abnormalities detected by cytogenetics, providing refinement of their genomic breakpoint locations as well as the identification of novel genomic changes. Three aCGH platforms, comprising bacterial artificial chromosome (BAC) or oligonucleotide templates, were available for evaluation. Sixteen CNAs were consistently detected by all three platforms. Novel submicroscopic CNAs ( approximately 0.4 Mb) were detected by the highest resolution platform only, whereas the clones from the BAC arrays provided locus-specific FISH probes for confirmation of CNA.
Assuntos
Leucemia Plasmocitária/genética , Linhagem Celular Tumoral , Bandeamento Cromossômico , Mapeamento Cromossômico , Perfilação da Expressão Gênica , Genoma Humano , Humanos , Hibridização in Situ Fluorescente , Cariotipagem , Hibridização de Ácido Nucleico , PrognósticoRESUMO
PURPOSE: To evaluate the effect on outcome of intensifying therapy for patients with acute lymphoblastic leukemia (ALL) and an intrachromosomal amplification of chromosome 21 (iAMP21). PATIENTS AND METHODS: We report two cohorts of patients treated on Medical Research Council ALL97 or United Kingdom (UK) ALL2003. iAMP21 was identified retrospectively in ALL97 and was not used to guide therapy. However, in UKALL2003, iAMP21 was determined prospectively, and patients were allocated to the most intensive treatment arm (regimen C), which included augmented Berlin-Frankfurt-Munster consolidation, escalating Capizzi maintenance, double delayed intensification, and an option for first remission transplantation. The presence of iAMP21 was determined by fluorescence in situ hybridization using probes specific for the RUNX1 gene. RESULTS: iAMP21 was identified in 2% of patients with B-cell precursor ALL treated on UKALL2003 and ALL97. The event-free survival, relapse, and overall survival rates at 5 years for iAMP21 patients treated on ALL97 and UKALL2003 were 29% and 78%, 70% and 16%, and 67% and 89%, respectively (all P < .01). Patients treated on ALL97 had an increased risk of relapse compared with patients treated on UKALL2003 (hazard ratio, 7.2; 95% CI, 2.91 to 17.87; P < .001). CONCLUSION: iAMP21 patients with ALL benefitted from receiving more intensive therapy in UKALL2003. In UKALL2011, they will continue to be treated as cytogenetic high risk, receive intensive chemotherapy (regimen C), and will only be recommended for transplantation if they do not achieve a complete remission by the end of induction therapy. This study illustrates how the discovery and characterization of disease-specific genetic aberrations can be used to tailor therapy more precisely.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Cromossomos Humanos Par 21 , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Criança , Citogenética , Feminino , Humanos , Hibridização in Situ Fluorescente , Masculino , Prognóstico , Estudos Prospectivos , Recidiva , Fatores de Risco , Análise de Sobrevida , Translocação GenéticaRESUMO
BACKGROUND: Health-related quality of life (HRQoL) has been recognized as an important target and health outcome in obesity research. The current study aimed to examine HRQoL in overweight or obese children after a 10-week primary-care-based weight management program, Parent-Led Activity and Nutrition for Healthy Living, in southern Appalachia. METHODS: Sixty-seven children (ages 5-12 years) and their caregivers were recruited from four primary care clinics, two of which were randomized to receive the intervention. Caregivers in the intervention groups received two brief motivational interviewing visits and four group sessions led by providers as well as four phone follow-ups with research staff. Caregivers completed the PedsQL and demographic questionnaires at baseline and at 3, 6, and 12 months postintervention. Child height and weight were collected to determine standardized BMI. RESULTS: Caregivers of children receiving the weight control intervention reported no statistically significant improvements in child total HRQoL, as compared to the control group, across the course of treatment (ß=0.178; 95% confidence interval, -0.681, 1.037; p=0.687). Additionally, no statistically significant improvements were found across other HRQoL domains. CONCLUSIONS: Future studies examining HRQoL outcomes in primary care may consider treatment dose as well as methodological factors, such as utilization of multiple informants and different measures, when designing studies and interpreting outcomes.
Assuntos
Pais , Obesidade Infantil/psicologia , Atenção Primária à Saúde , Qualidade de Vida , Redução de Peso , Programas de Redução de Peso , Adaptação Psicológica , Índice de Massa Corporal , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Relações Pais-Filho , Obesidade Infantil/prevenção & controle , Avaliação de Programas e Projetos de Saúde , Procurador , Autoimagem , Inquéritos e QuestionáriosRESUMO
Deletion of ATM detected by fluorescent in situ hybridization (FISH) in chronic lymphocytic leukemia predicts short treatment free survival and poor outcome following alkylator/purine analogue therapy. We describe five cases, with a diminished ATM FISH signal, investigated by TP53 mutation/dysfunction studies and single nucleotide polymorphism (SNP) array. The diminished signal represented loss of the ATM gene, which could have been missed were the cases not further investigated. These rare cases highlight the need for careful consideration of the choice of probe and interpretation of unusual signal patterns in FISH screening. We define a new minimal region of deletion at 11q22.3.
Assuntos
Proteínas de Ciclo Celular/genética , Deleção Cromossômica , Cromossomos Humanos Par 11/genética , Sondas de DNA , Proteínas de Ligação a DNA/genética , Hibridização in Situ Fluorescente , Leucemia Linfocítica Crônica de Células B/genética , Mutação/genética , Polimorfismo de Nucleotídeo Único/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Supressoras de Tumor/genética , Adulto , Idoso de 80 Anos ou mais , Proteínas Mutadas de Ataxia Telangiectasia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Taxa de Sobrevida , Proteína Supressora de Tumor p53/genéticaRESUMO
Child obesity has become an important public health concern, especially in rural areas. Primary care providers are well positioned to intervene with children and their parents, but encounter many barriers to addressing child overweight and obesity. This paper describes the design and methods of a cluster-randomized controlled trial to evaluate a parent-mediated approach utilizing physician's brief motivational interviewing and parent group sessions to treat child (ages 5-11 years) overweight and obesity in the primary care setting in Southern Appalachia. Specific aims of this pilot project will be 1) to establish a primary care based and parent-mediated childhood overweight intervention program in the primary care setting, 2) to explore the efficacy of this intervention in promoting healthier weight status and health behaviors of children, and 3) to examine the acceptability and feasibility of the approach among parents and primary care providers. If proven to be effective, this approach may be an exportable model to other primary care practices.
Assuntos
Estilo de Vida , Atividade Motora/fisiologia , Obesidade , Pais , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Índice de Massa Corporal , Peso Corporal , Comportamentos Relacionados com a Saúde , Humanos , Incidência , Estado Nutricional , Obesidade/epidemiologia , Obesidade/prevenção & controle , Obesidade/psicologia , Estados Unidos/epidemiologiaRESUMO
Intrachromosomal amplification of chromosome 21 (iAMP21), involving amplification of the RUNX1 gene and duplication of chromosome 21, dup(21q), defines a new cytogenetic subgroup in B-lineage acute lymphoblastic leukemia (ALL) with a poor prognosis. Characterization of this abnormality has become vital to ensure that the most accurate detection method is used. We have previously defined common regions of amplification and deletion of chromosome 21 in these patients, although the level and extent of amplification within the amplicon was highly variable. This study, using interphase fluorescence in situ hybridization (FISH) with chromosome 21 locus specific probes, substantiated these findings in a large series of patients and confirmed that the amplicon always included RUNX1. Thus, FISH with probes directed to the RUNX1 gene remains the most reliable detection method. Metaphase FISH, supported by G- and multiple color chromosomal banding (mBAND) revealed the patient specific morphology and genetic profile of the dup(21q) chromosomes, as well as the complexity of the intrachromosomal changes giving rise to them. These findings suggested that iAMP21 had arisen from a breakage-fusion-bridge cycle: a mechanism previously described in tumors, which we report for the first time in ALL.
Assuntos
Quebra Cromossômica , Cromossomos Humanos Par 21/genética , Translocação Genética/fisiologia , HumanosRESUMO
Patients with acute lymphoblastic leukemia (ALL) and an intrachromosomal amplification of chromosome 21 (iAMP21) comprise a novel and distinct biological subgroup. We prospectively screened 1630 (84%) patients treated on the UK MRC ALL97 protocol for iAMP21 and herein present demographic, clinical, and survival data on the 28 (2%) children found to harbor this abnormality. They had a common or pre-B ALL immunophenotype, were significantly older (median 9 years vs 5 years), and had a lower white cell count (median 3.9 vs 12.4) compared with children without this abnormality. Notably, patients with iAMP21 had a significantly inferior event-free and overall survival at 5 years compared with other patients: 29% (95% confidence interval [CI], 13%-48%) versus 78% (95% CI, 76%-80%) and 71% (95% CI, 51%-84%) versus 87% (95% CI, 85%-88%), respectively. As a result of this 3-fold increase in relapse risk, newly diagnosed patients with iAMP21 recruited to the current UK MRC ALL2003 trial are being treated on the high-risk arm and are considered for bone marrow transplantation in first remission.
Assuntos
Cromossomos Humanos Par 21/genética , Amplificação de Genes/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Criança , Pré-Escolar , Citogenética , Feminino , Humanos , Lactente , Masculino , Prognóstico , Taxa de SobrevidaRESUMO
We have previously identified a unique subtype of acute lymphoblastic leukemia (ALL) associated with a poor outcome and characterized by intrachromosomal amplification of chromosome 21 including the RUNX1 gene (iAMP21). In this study, array-based comparative genomic hybridization (aCGH) (n = 10) detected a common region of amplification (CRA) between 33.192 and 39.796 Mb and a common region of deletion (CRD) between 43.7 and 47 Mb in 100% and 70% of iAMP21 patients, respectively. High-resolution genotypic analysis (n = 3) identified allelic imbalances in the CRA. Supervised gene expression analysis showed a distinct signature for eight patients with iAMP21, with 10% of overexpressed genes located within the CRA. The mean expression of these genes was significantly higher in iAMP21 when compared to other ALL samples (n = 45). Although genomic copy number correlated with overall gene expression levels within areas of loss or gain, there was considerable individual variation. A unique subset of differentially expressed genes, outside the CRA and CRD, were identified when gene expression signatures of iAMP21 were compared to ALL samples with ETV6-RUNX1 fusion (n = 21) or high hyperdiploidy with additional chromosomes 21 (n = 23). From this analysis, LGMN was shown to be overexpressed in patients with iAMP21 (P = 0.0012). Genomic and expression data has further characterized this ALL subtype, demonstrating high levels of 21q instability in these patients leading to proposals for mechanisms underlying this clinical phenotype and plausible alternative treatments.
Assuntos
Cromossomos Humanos Par 21 , Regulação Neoplásica da Expressão Gênica , Predisposição Genética para Doença , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Alelos , Aberrações Cromossômicas , Cromossomos Artificiais Bacterianos , Perfilação da Expressão Gênica , Genoma , Genoma Humano , Genótipo , Humanos , Hibridização in Situ Fluorescente , Análise de Sequência com Séries de Oligonucleotídeos , FenótipoRESUMO
This study was undertaken in order to compare the interphase and metaphase cytogenetics of 28 patients with ETV6/RUNX1 positive acute lymphoblastic leukemia, at diagnosis and relapse. The median time to relapse was 26 months. The significant fusion positive population heterogeneity revealed at interphase by a commercial probe for ETV6/RUNX1 fusion has not been described before. Six diagnostic samples had a single abnormal population; others had up to five each, which differed in the numbers of RUNX1 signals, and in the retention or loss of the second ETV6 signal. In contrast, the number of fusion signals was more constant. At relapse, there were fewer populations; the largest or unique clone was sometimes a re-emergence of a minor, diagnostic one, with a retained copy of ETV6 and the most RUNX1 signals. Abnormal, fusion negative clones were identified in bone marrow samples at extra-medullary relapse. Variant three or four-way translocations, which involved chromosomes 12 and 21, were prominent among the complex rearrangements revealed by metaphase FISH. The frequency of their occurrence at diagnosis and reappearance at relapse, sometimes accompanied by minor clonal evolution, was another new observation. Other recurrent cytogenetic features included a second copy of the fusion signal in six cases, partial duplication of the long arm of the X chromosome in two cases, and trisomy 10 in three cases. In comparing our data with previously reported cases, a picture is beginning to emerge of certain diagnostic features, which may provide circumstantial evidence of an increased risk of relapse.
Assuntos
Fusão Gênica Artificial , Proteínas de Ligação a DNA/genética , Proteínas Nucleares/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Repressoras/genética , Fatores de Transcrição/genética , Adolescente , Adulto , Criança , Pré-Escolar , Mapeamento Cromossômico , Subunidade alfa 2 de Fator de Ligação ao Core , Feminino , Humanos , Hibridização in Situ Fluorescente , Lactente , Cariotipagem , Masculino , Pessoa de Meia-Idade , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Prognóstico , Proteínas Proto-Oncogênicas c-ets , Recidiva , Variante 6 da Proteína do Fator de Translocação ETSRESUMO
Summary Interphase fluorescence in situ hybridization (iFISH) was used independently to reveal chromosomal abnormalities of prognostic importance in a large, consecutive series of children (n = 2367) with acute lymphoblastic leukaemia (ALL). The fusions, TEL/AML1 and BCR/ABL, and rearrangements of the MLL gene occurred at frequencies of 22% (n = 447/2027) (25% in B-lineage ALL), 2% (n = 43/2027) and 2% (n = 47/2016) respectively. There was considerable variation in iFISH signal patterns both between and within patient samples. The TEL/AML1 probe showed the highest incidence of variation (59%, n = 524/884), which included 38 (2%) patients with clustered, multiple copies of AML1. We were thus able to define amplification of AML1 as a new recurrent abnormality in ALL, associated with a poor prognosis. Amplification involving the ABL gene, a rare recurrent abnormality confined to T ALL patients, was identified for the first time. The use of centromeric probes revealed significant hidden high hyperdiploidy of 33% and 59%, respectively, in patients with normal (n = 21/64) or failed (n = 32/54) cytogenetic results. The iFISH contributed significantly to the high success rate of 91% (n = 2114/2323) and the remarkable abnormality detection rate of 89% (n = 1879/2114). This study highlights the importance of iFISH as a complementary tool to cytogenetics in routine screening for significant chromosomal abnormalities in ALL.
Assuntos
Aberrações Cromossômicas , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adolescente , Criança , Pré-Escolar , Subunidade alfa 2 de Fator de Ligação ao Core , Análise Citogenética , Proteínas de Ligação a DNA/genética , Proteínas de Fusão bcr-abl/genética , Amplificação de Genes , Rearranjo Gênico , Genes abl , Histona-Lisina N-Metiltransferase , Humanos , Hibridização in Situ Fluorescente , Lactente , Interfase , Proteína de Leucina Linfoide-Mieloide , Proteínas de Fusão Oncogênica/genética , Prognóstico , Proto-Oncogenes/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/genéticaRESUMO
The recurrent t(14;19)(q32;q13) translocation associated with chronic B-cell lymphoproliferative disorders, such as atypical chronic lymphocytic leukemia, results in the juxtaposition of the IGH@ and BCL3 genes and subsequent overexpression of BCL3. We report six patients with B-cell precursor acute lymphoblastic leukemia who have a cytogenetically identical translocation with different breakpoints at the molecular level. Fluorescence in situ hybridization with locus-specific probes confirmed the involvement of the IGH@ gene but showed that the breakpoint on 19q13 lay outside the region documented in t(14;19)(q32;q13)-positive chronic lymphocytic leukemia. This newly described translocation constitutes a distinct cytogenetic subgroup that is confined to older children and younger adults with B-cell precursor acute lymphoblastic leukemia.
Assuntos
Cromossomos Humanos Par 14/genética , Cromossomos Humanos Par 19/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Translocação Genética/genéticaRESUMO
Prenatal acquisition of leukaemia-associated gene rearrangements is a well-established phenomenon. This is the first report of a complex cytogenetic clone, in association with an ETV6/AML1 fusion, developing in utero. Identical twin girls, aged 4 years, developed ETV6/AML1-positive acute lymphoblastic leukaemia (ALL) within 3 months of one another. Both demonstrated an identical four way, variant t(12;21). There was gain of an AML1 signal in twin 1 and loss of an ETV6 one in twin 2 at interphase. This unique case study demonstrates that ETV6/AML1 fusion and the associated complex chromosomal rearrangements occurred in utero. Clonal expansion of the abnormal cell in one twin was followed by metastasis to the other. There was a prolonged preleukaemic phase, which lasted well into childhood. The short time between the two diagnoses of ALL suggests a common precipitating event. The significance of the different secondary markers remains unclear.
Assuntos
Doenças em Gêmeos/embriologia , Doenças em Gêmeos/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/embriologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Translocação Genética , Pré-Escolar , Cromossomos Humanos Par 12 , Cromossomos Humanos Par 21 , Células Clonais , Subunidade alfa 2 de Fator de Ligação ao Core , Feminino , Humanos , Hibridização in Situ Fluorescente , Cariotipagem , Proteínas de Fusão Oncogênica/genética , Pré-Leucemia/embriologia , Pré-Leucemia/genética , Gêmeos MonozigóticosRESUMO
High hyperdiploidy (HeH) (51 to 65 chromosomes) is found in one third of children with acute lymphoblastic leukemia and is associated with a good prognosis. Cytogenetic features may further refine this prognosis and identify patients with a poor outcome. We examined the effect of sex, age, individual trisomies, modal number, and structural abnormalities on survival among 700 children with HeH. Univariate analysis showed that age. sex, +4, +10, +18, and a high modal number were associated with survival. Multivariate analysis however, revealed that only age, sex, +4, and +18 were independent indicators. Hazard scores for predicting relapse and mortality were constructed. Three risk groups with 5-year event-free survival (EFS) rates of 86%, 75%, and 50% (P <.0001) were identified. The high-risk group comprised boys older than 9 years, boys aged 1 through 9 years without +18, and girls older than 9 years without +18, while girls aged 1 through 9 years with +18 had the best EFS. In terms of mortality, those younger than age 10 years with both +4 and +18 had an improved survival (96% vs 84% at 5 years, P <.0001). These findings confirm that the outcome of children with HeH is heterogeneous and that specific trisomies can identify patients with the greatest and least risk of treatment failure.