Size-based molecular diagnostics using plasma DNA for noninvasive prenatal testing.

Noninvasive prenatal testing using fetal DNA in maternal plasma is an actively researched area. The current generation of tests using massively parallel sequencing is based on counting plasma DNA sequences originating from different genomic regions. In this study, we explored a different approach that is based on the use of DNA fragment size as a diagnostic parameter.

Cancer genome scanning in plasma: detection of tumor-associated copy number aberrations, single-nucleotide variants, and tumoral heterogeneity by massively parallel sequencing.

Background: Tumor-derived DNA can be found in the plasma of cancer patients. In this study, we explored the use of shotgun massively parallel sequencing (MPS) of plasma DNA from cancer patients to scan a cancer genome noninvasively.

Methods: Four hepatocellular carcinoma patients and a patient with synchronous breast and ovarian cancers were recruited.

FetalQuant: deducing fractional fetal DNA concentration from massively parallel sequencing of DNA in maternal plasma.

Motivation: The fractional fetal DNA concentration is one of the critical parameters for non-invasive prenatal diagnosis based on the analysis of DNA in maternal plasma. Massively parallel sequencing (MPS) of DNA in maternal plasma has been demonstrated to be a powerful tool for the non-invasive prenatal diagnosis of fetal chromosomal aneuploidies. With the rapid advance of MPS technologies, the sequencing cost per base is dramatically reducing, especially when using targeted MPS.

Nonhematopoietically derived DNA is shorter than hematopoietically derived DNA in plasma: a transplantation model.

Background: Plasma DNA is predominantly hematopoietic in origin. The size difference between maternal- and fetal-derived DNA in maternal plasma prompted us to investigate whether there was any discrepancy in molecular size between hematopoietically and nonhematopoietically derived DNA in plasma.

Methods: Plasma DNA samples from 6 hematopoietic stem cell transplant recipients and 1 liver transplant recipient were analyzed by massively parallel paired-end sequencing.

SFRS7-mediated splicing of tau exon 10 is directly regulated by STOX1A in glial cells.

Background: In this study, we performed a genome-wide search for effector genes bound by STOX1A, a winged helix transcription factor recently demonstrated to be involved in late onset Alzheimer's disease and affecting the amyloid processing pathway.

Methodology/principal Findings: Our results show that out of 218 genes bound by STOX1A as identified by chromatin-immunoprecipitation followed by sequencing (ChIP-Seq), the serine/arginine-rich splicing factor 7 (SFRS7) was found to be induced, both at the mRNA and protein levels, by STOX1A after stable transfection in glial cells. The increase in SFRS7 was followed by an increase in the 4R/3R ratios of the microtubule-associated protein tau (MAPT) by differential exon 10 splicing.

Noninvasive prenatal diagnosis of fetal trisomy 18 and trisomy 13 by maternal plasma DNA sequencing.

Massively parallel sequencing of DNA molecules in the plasma of pregnant women has been shown to allow accurate and noninvasive prenatal detection of fetal trisomy 21. However, whether the sequencing approach is as accurate for the noninvasive prenatal diagnosis of trisomy 13 and 18 is unclear due to the lack of data from a large sample set. We studied 392 pregnancies, among which 25 involved a trisomy 13 fetus and 37 involved a trisomy 18 fetus, by massively parallel sequencing.

Non-invasive prenatal assessment of trisomy 21 by multiplexed maternal plasma DNA sequencing: large scale validity study.

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 maternal plasma samples.

Setting: Prenatal diagnostic units in Hong Kong, United Kingdom, and the Netherlands.

Maternal plasma DNA sequencing reveals the genome-wide genetic and mutational profile of the fetus.

Cell-free fetal DNA is present in the plasma of pregnant women. It consists of short DNA fragments among primarily maternally derived DNA fragments. We sequenced a maternal plasma DNA sample at up to 65-fold genomic coverage.

Targeted massively parallel sequencing of maternal plasma DNA permits efficient and unbiased detection of fetal alleles.

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 approach for more efficient and cost-effective massively parallel sequencing because it increases the proportion of informative data from the targeted region(s).