Thesis (M.Med.Sc.)--University of Hong Kong, 2004. / Also available in print.

In the first part of this thesis, two chromosome Y specific genes ( SRYand TSPY) were chosen as the molecular targets to investigate the characteristics of fetal-specific DNA fragments in maternal plasma. By employing the touch down ligation-mediated PCR coupled with cloning and sequencing, the end property and the fragment species of fetal DNA were studied. / Noninvasive prenatal detection of fetal chromosomal aneuploidies is a much sought-after goal in fetomaternal medicine. The discovery of fetal DNA in the plasma of pregnant women has offered new opportunities for this purpose. However, the fact that fetal DNA amounts to just a minor fraction of all DNA in maternal plasma makes it challenging for locus-specific DNA assays to detect the small increase in sequences derived from a trisomic chromosome. On the other hand, although the clinical applications of plasma DNA for prenatal diagnosis are expanding rapidly, the biological properties of circulating DNA in plasma remain unclear. Recently, next-generation sequencing technologies have transformed the landscape of biomedical research through the ultra-high-throughput sequence information generated in a single run. Massively parallel sequencing allows us to study plasma DNA at an unprecedented resolution and also precisely detect fetal chromosomal aneuploidies in a locus-independent way. / Our group has demonstrated the use of massively parallel sequencing to quantify maternal plasma DNA sequences for the noninvasive prenatal detection of fetal trisomy 21. In the second part of this thesis, the clinical utility of this new sequencing approach was extended to the prenatal detection of fetal trisomy 18 and 13. A region-selection method was developed to minimize the effects of GC content on the diagnostic sensitivity and precision for the prenatal diagnosis of trisomy 13. To facilitate the next-generation sequencing-based maternal plasma DNA analysis for clinical implementation, two measures, i.e., lowering the starting volume of maternal plasma and barcoding multiple maternal plasma samples, were investigated. / Taken together, the results presented in this thesis have demonstrated the clinical utility of massively parallel sequencing of maternal plasma DNA and have also provided us a better understanding of the biology of circulating DNA molecules. / The third part of this thesis focuses on the massively parallel paired-end sequencing of plasma DNA. By analyzing millions of sequenced DNA fragments, the biological properties of maternal plasma DNA were elucidated, such as the size distribution of fetal-derived and maternally-contributed DNA molecules and the potential effect of epigenetic modification on DNA fragmentation. Moreover, the plasma DNA from hematopoietic stem cell transplant patients was characterized by paired-end sequencing approach. These sequencing data not only confirmed the predominant hematopoietic origin of cell-free DNA but also revealed the size difference between hematologically-derived and other tissue-derived DNA molecules in plasma. / Zheng, Wenli. / Adviser: Lo Yu Ming Dennis. / Source: Dissertation Abstracts International, Volume: 73-03, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 261-275). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Lo, Yin Wai Wyatt. / "December 2010." / Thesis (M.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 186-206). / Abstracts in English and Chinese. / ABSTRACT --- p.II / 摘要 --- p.VII / ACKNOWLEDGEMENTS --- p.X / PUBLICATIONS --- p.XI / TABLE OF CONTENTS --- p.XII / LIST OF TABLES --- p.XVIII / LIST OF FIGURES --- p.XXI / LIST OF ABBREVIATIONS --- p.XXIV / Chapter SECTION I: --- BACKGROUND --- p.1 / Chapter CHAPTER 1: --- PRENATALTESTNG --- p.2 / Chapter 1.1. --- THE AIM --- p.2 / Chapter 1.2. --- INVASIVE PRENATAL DIAGNOSIS --- p.4 / Chapter 1.3. --- NONINVASIVE PRENATAL SCREENING --- p.6 / Chapter CHAPTER 2: --- NONINVASIVE PRENATAL DIAGNOSIS --- p.10 / Chapter 2.1. --- CIRCULATING FETAL CELLS IN PRENATAL DIAGNOSIS --- p.10 / Chapter 2.2. --- CIRCULATING FETAL NUCLEIC ACIDS IN PRENATAL DIAGNOSIS --- p.12 / Chapter 2.3.1. --- Biology of circulating fetal DNA . --- p.14 / Chapter 2.3.2. --- Clinical applications of circulating fetal DNA --- p.15 / Chapter 2.3.2.1. --- Qualitative analysis of fetal DNA in maternal plasma --- p.16 / Chapter 2.3.2.2. --- Quantitative analysis of fetal DNA in maternal plasma --- p.17 / Chapter 2.4. --- CIRCULATING FETAL RNA IN MATERNAL PLASMA --- p.20 / Chapter 2.4.1. --- Biology of circulating fetal RNA --- p.20 / Chapter 2.4.2. --- Clinical applications of circulating fetal RNA --- p.22 / Chapter 2.4.2.1. --- Quantitative analysis of fetal RNA in maternal plasma --- p.22 / Chapter CHAPTER 3: --- TECHNICAL CHALLENGES IN ANALYZING CIRCULATING FETAL NUCLEIC ACIDS --- p.26 / Chapter 3.1. --- INTRODUCTION --- p.26 / Chapter 3.2. --- "PREANALYTICAL ISSUES IN MATERNAL PLASMA NUCLEIC ACID ANALYSE"";" --- p.28 / Chapter 3.2.1. --- Low abundance of cell-free fetal nucleic acids in maternal plasma --- p.28 / Chapter 3.2.2. --- High level of maternal background in maternal plasma --- p.30 / Chapter 3.3. --- ANALYTICAL ISSUES IN MATERNAL PLASMA NUCLEIC ACID ANALYS --- p.IS / Chapter 3.3.1. --- Imprecise measurement of fetal nucleic acid quantity --- p.33 / Chapter 3.3.2. --- Coexistence of fetal nucleic acids and maternal nucleic acid background in maternal plasma --- p.36 / Chapter 3.4. --- AIMS OF THIS THESIS --- p.41 / Chapter SECTION II: --- MATERIALS AND METHODS --- p.42 / Chapter CHAPTER 4: --- QUANTITATIVE AND QUALITATIVE ANALYSIS OF NUCLEIC ACIDS --- p.43 / Chapter 4.1. --- SAMPLE COLLECTION AND PROCESSING --- p.43 / Chapter 4.1.1. --- Preparation of plasma and blood cells --- p.43 / Chapter 4.1.2. --- Preparation of placental tissues --- p.44 / Chapter 4.2. --- NUCLEIC ACID EXTRACTION --- p.45 / Chapter 4.2.1. --- Extraction of total RNA --- p.45 / Chapter 4.2.1.1. --- Plasma samples --- p.45 / Chapter 4.2.1.2. --- Placental tissue samples --- p.46 / Chapter 4.2.2. --- Extraction of genomic DNA --- p.48 / Chapter 4.2.2.1. --- Plasma samples --- p.48 / Chapter 4.2.2.2. --- Blood cell samples --- p.48 / Chapter 4.3. --- CONVENTIONAL REAL-TIME PCR ANALYSIS OF NUCLEIC ACIDS --- p.50 / Chapter 4.3.1. --- Principles of real-time polymerase chain reaction --- p.50 / Chapter 4.3.2. --- Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) --- p.52 / Chapter 4.3.3. --- Quantitative polymerase chain reaction (qPCR) --- p.53 / Chapter 4.4. --- DIGITAL REAL-TIME PCR ANALYSIS OF NUCLEIC ACIDS --- p.55 / Chapter 4.4.1. --- Principles of digital PCR (dPCR) --- p.55 / Chapter 4.4.2. --- 384-reaction well dPCR v --- p.56 / Chapter 4.4.3. --- Microfluidics dPCR --- p.57 / Chapter 4.5. --- MATRIX-ASSISTED LASER DESORPTIONIONIZATION/TIME-OF-FLIGHT MASS SPECTROMETRY (MALDI-TOF MS) ANALYSIS OF NUCLEIC ACIDS --- p.59 / Chapter 4.5.1. --- Principles of MALDI-TOF MS --- p.59 / Chapter 4.5.2. --- DNA genotyping analysis by MassArray Homogenous MassExtend (hME) assay --- p.60 / Chapter 4.6. --- CLONING AND DNA SEQUENCING --- p.63 / Chapter SECTION III: --- IMPROVEMENTS ON MATERNAL PLASMA ANALYSIS OF CIRCULATING RNA --- p.65 / Chapter CHAPTER 5: --- ENRICHMENT OF PLACENTA EXPRESSED MRNA MARKERS BY WHOLE TRANSCRIPTOME PREAMPLIFICATION --- p.66 / Chapter 5.1. --- INTRODUCTION --- p.66 / Chapter 5.2. --- MATERIALS AND METHODS --- p.69 / Chapter 5.2.1. --- Study design --- p.69 / Chapter 5.2.2. --- Subjects and sample collection --- p.71 / Chapter 5.2.3. --- RNA extraction and sample dilution --- p.71 / Chapter 5.2.4. --- Preamplification --- p.73 / Chapter 5.2.5. --- qPCR analysis --- p.74 / Chapter 5.3. --- RESULTS --- p.83 / Chapter 5.3.1. --- Comparison of mRNA expression profiles in placental tissues with and without preamplification --- p.83 / Chapter 5.3.1.1. --- Undiluted placental tissue RNA --- p.84 / Chapter 5.3.1.2. --- Diluted placental tissue RNA --- p.88 / Chapter 5.3.2. --- The effect of RNA input on the degree of amplification --- p.92 / Chapter 5.3.2.1. --- Correlation between RNA input and RNA output --- p.94 / Chapter 5.3.2.2. --- Correlation between RNA input and output/input ratio --- p.96 / Chapter 5.3.3. --- Preamplification of maternal plasma RNA --- p.98 / Chapter 5.3.3.1. --- Concentrations of placenta expressed mRNA in third trimester maternal plasma --- p.98 / Chapter 5.3.3.2. --- Concentrations of placenta expressed mRNA in first trimester maternal plasma --- p.100 / Chapter 5.4. --- DISCUSSION --- p.102 / Chapter SECTION IV: --- IMPROVEMENTS ON MATERNAL PLASMA ANALYSIS OF CIRCULATING DNA --- p.105 / Chapter CHAPTER 6: --- ACCURATE GENE DOSAGE ANALYSIS BY MULTIPLEX QPCR --- p.106 / Chapter 6.1. --- INTRODUCTION --- p.106 / Chapter 6.2. --- MATERIALS AND METHODS --- p.110 / Chapter 6.2.1. --- Study design --- p.110 / Chapter 6.2.2. --- Subjects and sample collection --- p.112 / Chapter 6.2.3. --- DNA extraction and sample dilution --- p.113 / Chapter 6.2.4. --- qPCR analysis --- p.113 / Chapter 6.2.4.1. --- Monoplex assays --- p.114 / Chapter 6.2.4.2. --- Multiplex assays --- p.114 / Chapter 6.2.5. --- Microfluidics dPCR assay --- p.122 / Chapter 6.2.6. --- Gene Dosage Comparison --- p.122 / Chapter 6.2.6.1. --- In adult male samples --- p.123 / Chapter 6.2.6.2. --- In maternal plasma samples --- p.123 / Chapter 6.3. --- RESULTS --- p.125 / Chapter 6.3.1. --- The influence of using the same and different sets of primers for amplifying different chromosomal loci --- p.125 / Chapter 6.3.2. --- Effects of using monoplex and multiplex real-time PCR formulations --- p.130 / Chapter 6.3.3. --- Effects of incorporating calibration curves for template quantification in conventional qPCR --- p.135 / Chapter 6.4. --- DISCUSSION --- p.140 / Chapter CHAPTER 7: --- DPCR DETECTION OF PATERNALLY INHERITED POINT MUTATIONS --- p.144 / Chapter 7.1. --- INTRODUCTION --- p.144 / Chapter 7.2. --- MATERIALS AND METHODS --- p.153 / Chapter 7.2.1. --- Study design --- p.153 / Chapter 7.2.2. --- Subjects and sample collection --- p.157 / Chapter 7.2.3. --- DNA extraction and sample preparation --- p.158 / Chapter 7.2.4. --- MassArray hME assays --- p.159 / Chapter 7.2.5. --- dPCR assay --- p.159 / Chapter 7.3. --- RESULTS --- p.161 / Chapter 7.3.1. --- Validation of the digital HbE assay --- p.161 / Chapter 7.3.2. --- Determination of the minimum fetal DNA amount required for digital PCR detection --- p.165 / Chapter 7.3.3. --- Detection of paternally inherited fetal HbE mutation in maternal plasma --- p.172 / Chapter 7.4. --- DISCUSSION --- p.175 / Chapter SECTION V: --- CONCLUDING REMARKS --- p.180 / Chapter CHAPTER 8: --- CONCLUSION AND FUTURE PERSPECTIVES --- p.181 / Chapter 8.1. --- IMPROVEMENTS ON QUANTITATIVE AND QUALITATIVE ANALYSIS OF FETAL NUCLEIC ACIDS IN MATERNAL PLASMA --- p.181 / Chapter 8.2. --- PERSPECTIVES FOR FUTURE WORK --- p.184 / REFERENCES --- p.186

Chen, Zhang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (p. 109-114). / Abstracts in English and Chinese. / ABSTRACT --- p.I / 摘要 --- p.III / ACKNOWLEDGEMENTS --- p.IV / PUBLICATIONS --- p.VI / CONTRIBUTORS --- p.VII / TABLE OF CONTENTS --- p.VIII / LIST OF TABLES --- p.XIII / LIST OF FIGURES --- p.XIV / LIST OF ABBREVIATIONS --- p.XVI / Chapter SECTION I : --- BACKGROUND --- p.1 / Chapter CHAPTER 1: --- PRENATAL DIAGNOSIS OF FETAL TRISOMY BY NEXT GENERATION SEQUENCING TECHNOLOGY --- p.2 / Chapter 1.1 --- FETAL TRISOMY --- p.2 / Chapter 1.2 --- CONVENTIONAL PRENATAL DIAGNOSIS OF FETAL TRISOMIES --- p.3 / Chapter 1.3 --- CELL FREE FETAL D N A AND ITS APPLICATION IN PRENATAL DIAGNOSIS --- p.5 / Chapter 1.4 --- NEXT GENERATION SEQUENCING TECHNOLOGY --- p.5 / Chapter 1.5 --- SUBSTANTIAL BIAS IN THE NEXT GENERATION SEQUENCING PLATFORM --- p.9 / Chapter 1.6 --- PRENATAL DIAGNOSIS OF TRISOMY BY NEXT GENERATION SEQUENCING --- p.10 / Chapter 1.7 --- AIMS OF THIS THESIS --- p.11 / Chapter SECTION I I : --- MATERIALS AND METHODS --- p.13 / Chapter CHAPTER 2: --- METHODS FOR NONINVASIVE PRENATAL DIAGNOSIS OF FETAL TRISOMY MATERNAL PLASMA DNA SEQUENCING --- p.14 / Chapter 2.1 --- STUDY DESIGN AND PARTICIPANTS --- p.14 / Chapter 2.1.1 --- Ethics Statement --- p.14 / Chapter 2.1.2 --- "Study design, setting and participants" --- p.14 / Chapter 2.2 --- MATERNAL PLASMA D N A SEQUENCING --- p.17 / Chapter 2.3 --- SEQUENCING DATA ANALYSIS --- p.18 / Chapter SECTION I I I : --- TRISOMY 13 AND 18 DETECTION BY THE T21 BIOINFORMATICS ANALYSIS PIPELINE --- p.21 / Chapter CHAPTER 3: --- THE T21 BIOINFORMATICS ANALYSIS PIPELINE FOR TRISOMY 13 AND 18 DETECTION --- p.22 / Chapter 3.1 --- INTRODUCTION --- p.22 / Chapter 3.2 --- METHODS --- p.23 / Chapter 3.2.1 --- Bioinformatics analysis pipeline for trisomy 13 and 18 detection --- p.23 / Chapter 3.3 --- RESULTS --- p.23 / Chapter 3.3.1 --- Performance of the T21 bioinformatics analysis pipeline for trisomy 13 and 18 detection --- p.23 / Chapter 3.3.2 --- The precision of quantifying chrl 3 and chrl 8 --- p.27 / Chapter 3.4 --- DISCUSSION --- p.29 / Chapter SECTION IV : --- IMPROVING THE T21 BIOINFORMATICS ANALYSIS PIPELINE FOR TRISOMY 13 AND 18 DETECTION --- p.30 / Chapter CHAPTER 4: --- IMPROVING THE ALIGNMENT --- p.31 / Chapter 4.1 --- INTRODUCTION --- p.31 / Chapter 4.2 --- METHODS --- p.32 / Chapter 4.2.1 --- Allowing mismatches in the index sequences --- p.32 / Chapter 4.2.2 --- Calculating the mappability of the human reference genome --- p.33 / Chapter 4.2.3 --- Aligning reads to the non-repeat masked human reference genome --- p.34 / Chapter 4.2.4 --- Trisomy 13 and 18 detection --- p.34 / Chapter 4.3 --- RESULTS --- p.34 / Chapter 4.3.1 --- Increasing read numbers by allowing mismatches in the index sequences --- p.34 / Chapter 4.3.2 --- Increasing read numbers by using the non-masked reference genome for alignment . --- p.38 / Chapter 4.3.3 --- Allowing mismatches in the read alignment --- p.42 / Chapter 4.3.4 --- The performance of trisomy 13 and 18 detection after improving the alignment --- p.47 / Chapter 4.4 --- DISCUSSION --- p.50 / Chapter CHAPTER 5: --- REDUCING THE GC BIAS BY CORRECTION OF READ COUNTS --- p.53 / Chapter 5.1 --- INTRODUCTION --- p.53 / Chapter 5.2 --- METHODS --- p.54 / Chapter 5.2.1 --- Read alignment --- p.54 / Chapter 5.2.2 --- Calculating the correlation between GC content and read counts --- p.55 / Chapter 5.2.3 --- GC correction in read counts --- p.55 / Chapter 5.2.4 --- Trisomy 13 and 18 detection --- p.56 / Chapter 5.3 --- RESULTS --- p.56 / Chapter 5.3.1 --- GC bias in plasma DNA sequencing --- p.56 / Chapter 5.3.2 --- Correcting the GC bias in read counts by linear regression --- p.59 / Chapter 5.3.3 --- Correcting the GC bias in read counts by LOESS regression --- p.65 / Chapter 5.3.4 --- Bin size --- p.72 / Chapter 5.4 --- DISCUSSION --- p.75 / Chapter CHAPTER 6: --- REDUCING THE GC BIAS BY MODIFYING THE GENOMIC REPRESENTATION CALCULATION --- p.77 / Chapter 6.1 --- INTRODUCTION --- p.77 / Chapter 6.2 --- METHODS --- p.78 / Chapter 6.2.1 --- Modifying the genomic representation calculation --- p.78 / Chapter 6.2.2 --- Trisomy 13 and 18 detection --- p.78 / Chapter 6.2.3 --- Combining GC correction and modified genomic representation --- p.78 / Chapter 6.3 --- RESULTS --- p.79 / Chapter 6.3.1 --- Reducing the GC bias by modifying genomic representation calculation --- p.79 / Chapter 6.3.2 --- Combining GC correction and modified genomic representation --- p.86 / Chapter 6.4 --- DISCUSSION --- p.89 / Chapter CHAPTER 7: --- IMPROVING THE STATISTICS FOR TRISOMY 13 AND 18 DETECTION --- p.91 / Chapter 7.1 --- INTRODUCTION --- p.91 / Chapter 7.2 --- METHODS --- p.92 / Chapter 7.2.1 --- Comparing chrl 3 or chrl8 with other chromosomes within the sample --- p.92 / Chapter 7.2.2 --- Comparing chrl 3 or chrl 8 with the artificial chromosomes --- p.92 / Chapter 7.3 --- RESULTS --- p.93 / Chapter 7.3.1 --- Determining the trisomy 13 and 18 status by comparing chromosomes within the samples --- p.93 / Chapter 7.3.2 --- Determining the trisomy 13 and 18 status by comparing chrl3 or chrl 8 with artificial chromosomes --- p.97 / Chapter 7.4 --- DISCUSSION --- p.100 / Chapter SECTION V : --- CONCLUDING REMARKS --- p.102 / Chapter CHAPTER 8: --- CONCLUSION AND FUTURE PERSPECTIVES --- p.103 / Chapter 8.1 --- THE PERFORMANCE OF THE T21 BIOINFORMATICS ANALYSIS PIPELINE DEVELOPED FOR TRISOMY 21 DETECTION IS SUBOPTIMAL FOR TRISOMY 13 AND 18 DETECTION --- p.103 / Chapter 8.2 --- THE ALIGNMENT COULD BE IMPROVED BY ALLOWING ONE MISMATCH IN THE INDEX AND USING THE NON-REPEAT MASKED HUMAN REFERENCE GENOME AS THE ALIGNMENT REFERENCE --- p.104 / Chapter 8.3 --- THE PRECISION OF QUANTIFYING CHR13 AND CHR18 COULD BE IMPROVED BY THE G C CORRECTION OR THE MODIFIED GENOMIC REPRESENTATION --- p.104 / Chapter 8.4 --- THE STATISTICS FOR TRISOMY 13 AND 18 DETECTION COULD BE IMPROVED BY COMPARING CHR13 OR CHR18 WITH ARTIFICIAL CHROMOSOMES WITHIN THE SAMPLE --- p.105 / Chapter 8.5 --- PROSPECTS FOR FUTURE WORK --- p.106 / REFERENCE --- p.109