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OBJECTIVES To validate the clinical efficacy and practical feasibility of massively parallel maternal plasma DNA sequencing to screen for fetal trisomy 21 among high risk pregnancies clinically indicated for amniocentesis or chorionic villus sampling. DESIGN Diagnostic accuracy validated against full karyotyping, using prospectively collected or archived(More)
BACKGROUND The discovery of fetal DNA in maternal plasma has opened up an approach for noninvasive prenatal diagnosis. Despite the rapid expansion in clinical applications, the molecular characteristics of plasma DNA in pregnant women remain unclear. METHODS We investigated the size distribution of plasma DNA in 34 nonpregnant women and 31 pregnant women,(More)
BACKGROUND The precise measurement of cell-free fetal DNA in maternal plasma facilitates noninvasive prenatal diagnosis of fetal chromosomal aneuploidies and other applications. We tested the hypothesis that microfluidics digital PCR, in which individual fetal-DNA molecules are counted, could enhance the precision of measuring circulating fetal DNA. (More)
BACKGROUND Hypermethylation of the RASSF1A [Ras association (RalGDS/AF-6) domain family member 1A] gene is frequently observed in hepatocellular carcinoma (HCC). We evaluated the analysis of circulating hypermethylated RASSF1A for detecting HCC and assessing its prognosis. METHODS In module 1, we studied 63 pairs of HCC patients and age- and sex-matched(More)
Fully automated immunoassay formats are available for quantification of urinary albumin in large numbers of samples. However, most of these methods are impractical or expensive. The criteria for point-of-care testing include affordable cost, a disposable device, and minimum main-tenance/technical expertise required to perform tests (15). The sample should(More)
BACKGROUND The availability of an early diagnostic tool for severe acute respiratory syndrome (SARS) would have major public health implications. We investigated whether the SARS coronavirus (SARS-CoV) can be detected in serum and plasma samples during the early stages of SARS and studied the potential prognostic implications of such an approach. METHODS(More)
BACKGROUND We recently demonstrated that the promoter of the RASSF1A gene is hypermethylated in the placenta and hypomethylated in maternal blood cells. This methylation pattern allows the use of methylation-sensitive restriction enzyme digestion for detecting the placental-derived hypermethylated RASSF1A sequences in maternal plasma. METHODS We performed(More)
BACKGROUND The use of fetal DNA in maternal plasma for noninvasive prenatal diagnosis of trisomy 21 (T21) is an actively researched area. We propose a novel method of T21 detection that combines fetal-specific epigenetic and genetic markers. METHODS We used combined bisulfite restriction analysis to search for fetal DNA markers on chromosome 21 that were(More)
  • Gary J W Liao, Fiona M F Lun, +5 authors Y M Dennis Lo
  • 2011
BACKGROUND Massively parallel sequencing has recently been used in noninvasive prenatal diagnosis. The current costs of this technology are still relatively expensive, however, and sample throughput is still relatively low when it is used as a molecular diagnostic tool. Rather than nonselectively sequencing the genome, target enrichment provides a logical(More)
BACKGROUND Cell-free fetal DNA (cffDNA) constitutes approximately 10% of the cell-free DNA in maternal plasma and is a suitable source of fetal genetic material for noninvasive prenatal diagnosis (NIPD). The objective of this study was to determine the feasibility of using digital PCR for NIPD in pregnancies at risk of sickle cell anemia. METHODS(More)