Trisomy 21 (T21), trisomy 18 (T18) and trisomy 13 (T13) represent the most common autosomal trisomies detected in live-born infants. Previous studies have addressed interventions, morbidities and survival in term or near-term infants with T21, T18 or T13, or were limited by a small number of patients. However, the combination of one of these chromosomal anomalies and very low birth weight (VLBW) presents greater challenges. Data from the NICHD Neonatal Research Network (NRN) and from the Vermont Oxford Network (VON) databases were used to examine the frequency, interventions, risk of mortality and neonatal morbidities, including patent ductus arteriosus (PDA), necrotizing enterocolitis (NEC), late onset sepsis (LOS), retinopathy of prematurity (ROP), and bronchopulmonary dysplasia (BPD), among VLBW infants with T21, T18 or T13 compared to VLBW infants without major birth defects (BD) and VLBW infants with non-chromosomal BD. Anthropometric VON charts for the assessment of birth weight for gestational age among 22 week to term infants with T21, T18 or T13 were also developed. In the VON database (n=539,509), the frequency of VLBW infants diagnosed with T21 was 1681 (0.31%), with T18 was 1416 (0.27%), and with T13 was 435 (0.08%). Major surgery was reported for 30.4% of infants with T21, 9.2% with T18, and 6.8% with T13. In-hospital mortality occurred for 33.1% of infants with T21, 89.0% with T18, and 92.4% with T13. Median survival time was 4 days (95% CI: 3-4) among infants with T18 and 3 days (95% CI: 2-4) among infants with T13. Birth weight for gestational age charts were created using VON data with a total of 5147 infants with T21 aged 22-41 weeks, 1053 infants with T18 aged 22-41 weeks, and 613 infants with T13 aged 22-40 weeks. Among the three groups, infants with T18 were the most likely to be growth restricted while infants with T21 were the least likely to be growth restricted. The new anthropometric VON charts for infants with T21 were also compared to the Lubchenco and Fenton charts and both showed frequent misclassification of infants with T21 as small or large for gestational age. In the NICHD NRN database (n=52,259), 133 (0.26%) VLBW infants were diagnosed with T21, 132 (0.25%) with T18 and 40 (0.08%) with T13. The adjusted relative risk, estimated using Poisson regression models with robust variance estimators, showed an increased risk of death, PDA, NEC, LOS, and BPD among infants with T21 relative to infants with no BD. Relative to infants with non-chromosomal BD, infants with T21 were at increased risk of PDA and NEC. A trend toward a lower risk of ROP was observed among infants with T21 compared to infants with non-chromosomal BD and infants without major BD. Infants with T13, but not infants with T18, were less likely to be mechanically ventilated than infants with T21 and infants without BD. Infants with T18 had increased risk of PDA compared to infants with T13, infants with T21 and infants without BD and increased risk of BPD compared to infants with T21 and infants without BD. The current studies evaluated the largest cohorts of VLBW infants with T21, T18 or T13. These data are important to help families and care providers make informed decisions involving the care of their VLBW infants with these chromosomal anomalies.

No description available.

Thesis (M.S.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains vi, 41 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 39-41).

Down syndrome, also referred to as trisomy 21, is a chromosomal abnormality in which the 21st human chromosome is partially or entirely duplicated. It is associated with a myriad of characteristics, including distinct facial deformities, intellectual disability, a heart defect, low muscle tone, and development of Alzheimer's disease symptoms with aging. This duplication is associated with increased levels of gene expression relative to what is present in euploid cells and disrupts the structure of some gene products. This study examines current mouse models of trisomy 21, describes a bioinformatics approach to evaluate relationships between genes on chromosome 21, and to determine the role they may play in Down syndrome associated intellectual disability. The Ts1Rhr, Tc1, and Ts65Dn mouse models are compared and contrasted to human trisomy 21. Representation of intellectual disability is determined by how the mice in each model perform on learning and memory tasks. Each model is examined for duplication of Down syndrome associated genes as well as for body weight, cerebral size, cerebellar size, balance, motor coordination, learning and memory, attention, activity, presence or absence of a heart defect, and presence or absence of a craniofacial defect. Next, a bioinformatics approach is proposed as tool with the capacity to examine the individual genes on chromosome 21, the relationships between the genes, group genes together by functional similarity and biological implication, and then establish which of these groups are enriched. The combined evaluation of mouse models and bioinformatics can be used as an innovative way to study the involvement in the intellectual disability associated with Down syndrome. Through the review of current mouse models and the evaluation of individual chromosome 21 genes using bioinformatics resources, the study seeks to determine what insights on intellectually disability can be gained.

Drosophila melanoqaster individuals trisomic for an entire chromosome arm can survive to late stages of pupal development. To examine gene expression in these hyperploids, the levels of five enzymes whose structural genes are located on the left arm of chromosome two have been examined both in aneuploid and in diploid strains. Elevated levels of enzyme activity were observed in larvae possessing small segmental duplications for these genes. However, in 2L trisomies, the three distally mapping loci showed compensated levels of expression close to that observed in the diploid strains. Analysis of electrophoretic variants revealed that for one of these compensated loci all three alleles were expressed in trisomies. Two proximally located genes displayed dose-dependent levels of enzyme activity. For most genes, autosomal compensation appears to be very discrete: either the expression of the gene is repressed or it is not. To extend these observations, and to determine if autosomal compensation was peculiar to the left arm of chromosome two, trisomies for the X, for 2R, and for 3L also were examined. Compensating and non-compensating loci were also found on 3L, whereas all loci examined in X-chromosomal trisomies were dosage compensated. This suggests that X-chromosomal and autosomal trisomies are not necessarily analagous. Dosage compensation in X-chromosomal trisomies (metafemales) may occur exclusively or partially by the mechanism that operates between euploid males and females. However, some compensation in X trisomies may occur by regulatory controls distinct from male-female dosage compensation as indicated by the following results. The expression of LSP-1aT a gene that normally escapes complete dosage compensation in diploid males, was fully compensated in trisomic-X larvae. Possibly, compensation of this gene in these individuals was mediated by regulatory mechanisms other than those controlling male-female dosage compensation. As such, loci that normally do not reside on the X chromosome, but which have been transposed to this chromosome, might be expected to escape compensation in metafemales. This appears to be the case; an Adh gene that had been transposed from the second to the X chromosome was expressed at a similar level (per gene) in metafemales and females. In addition, a native X-chromosomal locus appeared to be compensated between males and females, but was not compensated in X-chromosomal trisomies. Thus, some X-linked loci escape regulation by dosage compensation in metafemales. It is possible that some of the regulatory systems operating in X-chromosomal and autosomal trisomies are analagous, and reflect a common form hyperploid compensation. The level at which compensation occured was investigated by measuring the quantities of RNA produced by several genes in whole-arm trisomies. For the heat-shock gene, hsp 85. compensation for protein levels appeared to be Post-transcriptionally regulated. However, measurements of RNA synthesis on salivary gland polytene chromosomes revealed that for most of the genes compensation was transcriptionally regulated. Dosage compensation on the autosomes probably reflects the existence of a system that normally operates in diploids to control gene expression by negative regulation. / Science, Faculty of / Zoology, Department of / Graduate

Quantitative fluorescence polymerase chain reaction (QF-PCR) is a molecular genetic method based on the amplification of microsatellites (Short tandem repeats, STR) and measurement of the peak heights of amplicons in the electropherogram. Currently, the QF-PCR deemed reliable, fast, and inexpensive method that is gradually replacing conventional cytogenetic analysis of aneuploidy (examination of long-term cultures of amniotic fluid). However, in certain cases it is impossible to determine the parental origin and meiotic aneuploidy by QF-PCR. The aim of this work was to verify the new dinucleotide STR markers on chromozomes 13, 16, 18, 21, and 22 and further increase the diagnostic efficiency of QF-PCR retaining other STR markers on chromozome 15, 16, 22 and to determine the population and the analytical characteristics of these markers. For all dinucleotide STR markers stutter occurred in high frequency and therefore there were found not to be suitable for routine diagnostics. STR markers for chromozomes 15, 16 and 22 were tested on 100 patients. We selected four informative markers for both chromozome 16 and 22, and three markers for chromozome 15. Thus, I expanded set of diagnostic STR markers in this thesis.

No description available.

No description available.

Introdução: As trissomias 18 (T18) e Trissomia 13 (T13) são respectivamente a segunda e terceira causa mais comum de aneuploidias, com um aumento no diagnóstico dado o desenvolvimento de métodos e protocolos que incluem rastreio ecográfico e bioquímico, com a possibilidade de realizar um diagnóstico pré-natal a partir da realização de cariótipo fetal. São síndromes polimalformativas graves, potencialmente letais, associadas a uma alta taxa de aborto espontâneo, morte intrauterina e uma vida pós-natal curta, com morte neonatal precoce. O presente estudo visa descrever e analisar a história natural destas trissomias em um país onde não há previsão legal para interrupção terapêutica para estes casos. Objetivos Analisar e descrever a história natural das gestações com diagnóstico pré-natal de trissomia 13 e trissomia 18, identificadas através da realização de amniocentese para obtenção de cariótipo, que foram realizadas entre outubro de 1994 até outubro de 2017 no Serviço de Ginecologia e Obstetrícia do Hospital de Clínicas de Porto Alegre e acompanhadas pelo grupo de Medicina Fetal, e assim comparar os dados encontrados nesta casuística local com a literatura atual a respeito do tema. Métodos: Realizado análise dos prontuários das pacientes que realizaram cariótipo fetal através de amniocentese, e fizeram diagnóstico pré-natal de trissomia 13 ou trissomia 18.Quando incompletos, foram realizadas ligações telefônicas para completá-los. A partir dos dados coletados (demográficos, ecográficos, curso da gestação) foram avaliados os possíveis desfechos fetais (abortamento espontâneo, óbito fetal e nascido vivo), descrevendo a sua história natural, e considerando principalmente a sobrevida dos nativivos. Análise estatística usando SPSS versão 18.0. Resultados: Quarenta e duas pacientes foram incluídas, sendo 13 (31%) T13 e 29 (69%) T18. Todos os casos fizeram cariótipo para diagnóstico pré-natal através de amniocentese. 92,9% das pacientes foram encaminhadas devido a malformações detectadas em ecografia. Na avaliação das malformações, encontrou-se que a identificação de fenda labial e/ou palatina (p 0,008), dilatação pielocalicial (p 0,037) e holoprosencefalia (p <0,0001) foram achados ecográficos com significância estatística freqüentes em T13. A taxa de abortamento foi de 9% para T18, enquanto não houve casos em T13. Óbito fetal aconteceu em 46% e 52% dos casos para T13 e T18 respectivamente. A taxa de nascidos vivos foi de 54% para T13, sendo que a mediana de sobrevida foi de um dia (IC95% -33,55-90,40). 71% dos casos morreram nas primeiras 24 horas e dois casos que ultrapassaram a primeira semana de vida: com 14 dias e 180 dias respectivamente. Para T18 a mediana de sobrevida foi de dois dias [IC95% -1,89-13,17]. Cinco casos (45%) faleceram dentro das primeiras 24 horas. Outros 45% morreram na primeira semana de vida. Um caso (10%) ultrapassou o primeiro mês de vida, com sobrevida de 39 dias. Nenhum caso em ambas as trissomias ultrapassou o primeiro ano de vida. Conclusões: Os resultados deste estudo são consistentes com os referenciados na literatura acerca do diagnóstico de T13 e T18, quando realizado no pré-natal. A presença de malformações em ecografia foi o que mais motivou o encaminhamento para o atendimento especializado e realização de procedimentos diagnósticos, sendo identificados alguns achados característicos que podem aumentar a suspeita diagnóstica, quando detectados no exame ultrassonográfico, principalmente para trissomia 13, como são a defeitos de línea media e dilatação pielocalicial. Além disso, foi possível confirmar as características de síndrome polimalformativa potencialmente letal, destas trissomias quando avaliada a história natural, caracterizando-se por uma taxa alta de morte fetal intra-uterina e com uma sobrevida global curta ao nascimento. Este estudo também proporcionará informações importantes para definir condutas e protocolos de manejo e acompanhamento a serem executadas por equipes multidisciplinares treinadas, que permitam adequados processos de aconselhamento pré-concepcional e genético, e assim facilitar a tomada de decisões pela paciente gestante, seu parceiro e a família. Além disso, proporcionará informações que permitam reavaliar as políticas em saúde coletiva, abrindo a discussão sobre se deve também ser considerada a interrupção terapêutica da gestação em casos de trissomia 13 e trissomia 18 a partir do desejo dos pais e da autorização judicial. / Introduction: Trisomy 18 (T18) and Trisomy 13 (T13) are respectively the second and third most common cause of aneuploidies, with an increase in diagnosis given the development of methods and protocols that include ultrasound and biochemical screening, with the possibility of performing a prenatal diagnosis from the fetal karyotype. These are a serious, potentially lethal polymalformative syndromes associated with a high rate of spontaneous abortion, intrauterine death and short postnatal life with early neonatal death. The present study aims to describe and analyze the natural history of these trisomies in a country where there is no consider a legal provision for therapeutic interruption in these cases. Objectives To analyze and describe the natural history of pregnancies with prenatal diagnosis of trisomy 13 and trisomy 18, identified through amniocentesis to obtain a fetal karyotype, which were performed between October 1994 and October 2017 at the Gynecology and Obstetrics Service of Hospital de Clínicas de Porto Alegre and accompanied by the Fetal Medicine Group, and thus compare the data found in this local casuistry with the current literature on the subject. Methods: Analyzed the medical records of patients who performed a fetal karyotype, through amniocentesis, for prenatal diagnosis of trisomy 13 or trisomy 18. When incomplete, telephone calls were made to complete them. The possible fetal outcomes (spontaneous abortion, fetal death and live birth), describing their natural history, and considering mainly the survival of the 16 children were born alive. Data about each patient was collected and organized (demographic, ultrasound, gestation course) in order to do a secondary analysis. Statistical analysis using SPSS version 18.0. Results: Forty-two patients were included, being 13 (31%) T13 and 29 (69%) T18. All cases had a fetal karyotype for prenatal diagnosis through amniocentesis. 92.9% of the patients were referred due to malformations detected on ultrasound. In the malformations assessment, it was found that the identification of cleft lip and / or palate (p 0.008), pyelocalycial dilatation (p 0.037) and holoprosencephaly (p <0.0001) were frequent echographic findings in T13. The abortion rate was 9% for T18, while there were no cases in T13. Fetal death occurred in 46% and 52% of cases for T13 and T18 respectively. The rate of live births was 54% for T13, and the median survival was one day [95% CI - 33.55-90.40]. 71% of the cases died in the first 24 hours and two cases that exceeded the first week of life: 14 days and 180 days respectively. For T18 the median survival was 2 days [95% CI -1.89-13.17]. Five cases (45%) died within the first 24 hours. Another 45% died in the first week. One case (10%) exceeded the month of life, with a survival of 39 days. No case in both trisomies has exceeded the year of life. Conclusions The results of this study are consistent with those referenced in the literature on the diagnosis of T13 and T18, when performed in the prenatal period. The presence of malformations in ultrasound was the most motivated the referral to specialized care and diagnostic procedures, being identified some characteristic findings that can increase the diagnostic suspicion, when detected in the ultrasound examination, mainly for trisomy 13, as they are defects of midline and pyelocalycial dilatation. In addition, it was possible to confirm the characteristics of a potentially lethal polymalformative syndrome of these trisomies when evaluated its natural history, characterized by a high rate of intrauterine fetal death and short overall survival at birth. This study will also provide important information to define management and follow-up procedures and protocols to be carried out by trained multidisciplinary teams that allow adequate preconceptional and genetic counseling processes, and thus facilitate decision making by the pregnant patient, her partner and the family. In addition, it will provide information to reassess collective health policies, opening the discussion on whether to also consider the therapeutic interruption of gestation in cases of trisomy 13 and trisomy 18, based on parental desire and judicial authorization.

Lam, Yuk Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 142-157). / Abstracts in English and Chinese. / ABSTRACT --- p.i / 摘要 --- p.iv / ACKNOWLEDGEMENTS --- p.vi / CONTRIBUTORS --- p.viii / PUBLICATIONS --- p.ix / LIST OF TABLES --- p.x / LIST OF FIGURES --- p.xi / LIST OF ABBREVIATIONS --- p.xiii / TABLE OF CONTENTS --- p.xiv / Chapter SECTION I: --- BACKGROUND --- p.1 / Chapter CHAPTER 1: --- PRENATAL DIAGNOSIS OF FETAL ANEUPLOIDIES --- p.2 / Chapter 1.1 --- The need for prenatal screening and diagnosis --- p.2 / Chapter 1.2 --- Patau Syndrome (Trisomy 13) --- p.2 / Chapter 1.3 --- Current methods for fetal aneuploidy detection --- p.4 / Chapter 1.3.1 --- Routine prenatal screening tests --- p.4 / Chapter 1.3.2 --- Definitive prenatal diagnosis by invasive procedures --- p.7 / Chapter 1.4 --- New approach for noninvasive prenatal diagnosis --- p.11 / Chapter 1.4.1 --- Circulating fetal cells --- p.11 / Chapter 1.4.2 --- Cell-free fetal nucleic acids in maternal circulation --- p.12 / Chapter 1.4.3 --- Diagnostic applications of cell-free fetal nucleic acids in maternal plasma --- p.12 / Chapter CHAPTER 2: --- DEVELOPMENT OF FETAL EPIGENETIC MARKERS IN MATERNAL PLASMA --- p.17 / Chapter 2.1 --- Limitations of fetal DNA markers --- p.17 / Chapter 2.2 --- DNA methylation is an actively-researched area under the field of epigenetics --- p.18 / Chapter 2.3 --- Genome-scale DNA methylation analysis brings new insight into epigenetics --- p.20 / Chapter 2.4 --- The first demonstration of using an epigenetic method for detecting maternally-inherited fetal DNA in maternal plasma --- p.22 / Chapter 2.5 --- The first universal marker for fetal DNA in maternal plasma --- p.24 / Chapter 2.6 --- Discovery of more fetal epigenetic markers --- p.25 / Chapter 2.6.1 --- Methylated fetal epigenetic markers are more desirable --- p.25 / Chapter 2.6.2 --- Discovery of hypermethylated fetal epigenetic markers by studying tumor suppressor genes --- p.26 / Chapter 2.6.3 --- Discovery of hypermethylated fetal epigenetic markers on chromosome 21 --- p.28 / Chapter 2.7 --- Noninvasive detection of fetal aneuploidies using fetal epigenetic markers --- p.29 / Chapter 2.7.1 --- Noninvasive detection of fetal trisomy 18 by the epigenetic allelic ratio (EAR) approach --- p.29 / Chapter 2.7.2 --- Noninvasive detection of fetal trisomy 21 by the epigenetic-genetic (EGG) approach --- p.30 / Chapter 2.8 --- Aim of thesis --- p.32 / Chapter SECTION II: --- MATERIALS AND METHODS --- p.34 / Chapter CHAPTER 3: --- METHODS FOR QUANTITATIVE ANALYSIS OF DNA METHYLATION --- p.35 / Chapter 3.1 --- Subject recruitment and sample collection --- p.35 / Chapter 3.2 --- Sample processing --- p.38 / Chapter 3.3 --- DNA extraction --- p.38 / Chapter 3.3.1 --- Placental tissues --- p.38 / Chapter 3.3.2 --- Maternal blood cells --- p.39 / Chapter 3.3.3 --- Maternal plasma --- p.40 / Chapter 3.4 --- Methylated DNA immunoprecipitation and tiling array analysis (MeDIP-chip) --- p.41 / Chapter 3.4.1 --- Principles --- p.41 / Chapter 3.4.2 --- DNA sample and array processing --- p.43 / Chapter 3.4.2.1 --- DNA preparation and target hybridization --- p.43 / Chapter 3.4.2.2 --- Data analysis --- p.44 / Chapter 3.5 --- DNA methylation analysis on randomly-chosen regions on chromosome / Chapter 3.6 --- Bisulfite conversion --- p.46 / Chapter 3.6.1 --- Principles of bisulfite conversion --- p.46 / Chapter 3.6.2 --- Procedures of bisulfite conversion --- p.46 / Chapter 3.7 --- Quantitative analysis of DNA methylation --- p.47 / Chapter 3.7.1 --- Bisulfite PCR and genomic sequencing --- p.47 / Chapter 3.7.1.1 --- Primer design for bisulfite polymerase chain reaction (PCR) --- p.47 / Chapter 3.7.1.2 --- Bisulfite PCR --- p.49 / Chapter 3.7.1.3 --- Cloning --- p.50 / Chapter 3.7.1.4 --- Bisulfite genomic sequencing --- p.52 / Chapter 3.7.1.5 --- Data acquisition and interpretation --- p.53 / Chapter 3.7.2 --- EpiTYPER，a mass-spectrometry-based method --- p.54 / Chapter 3.7.2.1 --- Principles of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) --- p.54 / Chapter 3.7.2.2 --- Primer design of the EpiTYPER assay --- p.55 / Chapter 3.7.2.3 --- The EpiTYPER assay and its principle --- p.56 / Chapter 3.8 --- Methylation-sensitive restriction enzyme (MSRE)-mediated real-time quantitative PCR (qPCR) --- p.61 / Chapter 3.9 --- Digital PCR --- p.66 / Chapter 3.9.1 --- Principles of digital PCR --- p.66 / Chapter 3.9.2 --- Poisson distribution --- p.68 / Chapter 3.10 --- Statistical analyses --- p.69 / Chapter SECTION III: --- SYSTEMATIC IDENTIFICATION OF A FETAL DNA METHYLATION MARKER ON CHROMOSOME 13 FOR DETECTION OF FETAL TRISOMY 13 --- p.70 / Chapter CHAPTER 4: --- SYSTEMATIC IDENTIFICATION OF POTENTIAL FETAL EPIGENETIC MARKERS BY MEDIP-CHIP ANALYSIS --- p.71 / Chapter 4.1 --- Systematic discovery of fetal epigenetic markers on chromosome 13 by MeDIP-chip analysis --- p.71 / Chapter 4.2 --- Experimental design --- p.73 / Chapter 4.3 --- Results --- p.76 / Chapter 4.3.1 --- Identification of differentially methylated DNA regions by MeDIP-chip or non-MeDIP-chip approaches followed by EpiTYPER analysis --- p.76 / Chapter 4.3.2 --- Confirmation of differential methylation patterns and exclusion of regions with high inter-individual variations by EpiTYPER analysis --- p.82 / Chapter 4.3.3 --- Confirmation of differential DNA methylation patterns with higher resolution by bisulfite sequencing --- p.85 / Chapter 4.4 --- Discussion --- p.95 / Chapter CHAPTER 5: --- THE APPLICATION OF FETAL EPIGENETIC MARKER ON CHROMSOME 13 FOR DETECTION OF FETAL TRISOMY 13 --- p.98 / Chapter 5.1 --- Identification of a fetal epigenetic marker on chromosome 13 for the detection of fetal trisomy 13 by the epigenetic-genetic (EGG) chromosome dosage approach --- p.98 / Chapter 5.2 --- Experimental design --- p.101 / Chapter 5.3 --- Results --- p.105 / Chapter 5.3.1 --- Optimization of the digestion protocol --- p.105 / Chapter 5.3.2 --- Detection of digestion-resistant EFNB2-3'UTR moleculesin maternal plasma --- p.109 / Chapter 5.3.3 --- Evaluation of the fetal specificity of digestion-resistant EFNB2´ؤ3 'UTR DNA molecules in maternal plasma --- p.111 / Chapter 5.3.4 --- Comparison of EFNB2-3'UTR methylation profiles between the euploid and trisomy 13 placental tissue samples --- p.115 / Chapter 5.3.5 --- Chromosome dosage analysis by the EGG analysis using placental tissue samples --- p.118 / Chapter 5.4 --- Discussion --- p.122 / Chapter SECTION IV: --- CONCLUDING REMARKS --- p.125 / Chapter CHAPTER 6: --- CONCLUSION AND FUTURE PERSPECTIVES --- p.126 / Chapter 6.1 --- Development of fetal epigenetic markers for noninvasive prenatal diagnosis --- p.126 / Chapter 6.2 --- Systematic identification of fetal epigenetic markers on chromosome13 --- p.127 / Chapter 6.3 --- Detection of fetal trisomy 13 by the epigenetic-genetic (EGG) relative chromosome dosage analysis --- p.129 / Chapter 6.4 --- Future perspectives --- p.132 / Appendix I --- p.134 / Appendix II --- p.136 / REFERENCES --- p.142