Free fetal dna

A "sandwich-like" biosensor was developed based on the magnetic bead platform for sensitive detection of breast cancer 1 (BRCA1) DNA. In the present study, a tetrahedron-structured reporter probe (TSRP) was designed, in which 3 vertices of the tetrahedron were labelled with digoxin (Dig) and the other one was labelled with a detection probe. TSRP here provided accurate enzyme loading and well-organized spatial arrangement for optimized signal amplification. The detection limit of this biosensor was as low as 10 fM, which is at least 4 orders of magnitude lower than the single DNA probe (100 pM), and the signal gain was 2 times higher than the analysis using three one-dimensional (1D) reporter probes...

BACKGROUND: Noninvasive prenatal testing (NIPT) uses cell-free DNA (cfDNA)(5) as an analyte to detect copy-number alterations in the fetal genome. Because maternal and fetal cfDNA contributions are comingled, changes in the maternal genome can manifest as abnormal NIPT results. Circulating tumor DNA (ctDNA) present in cases of maternal neoplasia has the potential to distort the NIPT readout to a degree that prevents interpretation, resulting in a nonreportable test result for fetal aneuploidy...

Non-invasive prenatal screening (NIPS) has revolutionized the approach to prenatal fetal aneuploidy screening. Many commercial providers now offer analyses for sub-chromosomal copy number variations (CNVs). Here, we review the use of NIPS in the context of screening for microdeletions and microduplications, issues surrounding the choice of disorders tested for, and the advantages and disadvantages associated with the inclusion of microdeletions to current NIPS. Several studies have claimed benefits; however, we suggest that microdeletions have not demonstrated a low enough false positive rate to be deemed practical or ethically acceptable, especially considering their low positive predictive values...

The biomedical technology related to prenatal screen/diagnosis has developed rapidly in recent decades. Many prenatal genetic examinations are now available to assist pregnant women to better understand the status and development of their fetus. Moreover, many commercial advertisements for innovative prenatal examinations are now shown in the media. Cell-free DNA Screening (cfDNA screening), a non-invasive prenatal testing (NIPT) procedure, is a safe and high accuracy test that may be done at an earlier gestational age to screen for fetal aneuploidy...

The midsagittal view of the fetal profile is essential in first trimester screening at 11 + 0 to 13 + 6 weeks of gestation. None of the standard sections in prenatal medicine is as well defined and undergoes such a strong quality assurance program. These requirements were recently challenged by the introduction of cell-free DNA screening. The fetal profile view was previously only needed for the appropriate measurement of the fetal nuchal translucency thickness. In recent years, it became evident that there are many more anomalies or markers for fetal defects that can be seen in this section such as spina bifida, facial clefts or retrognathia...

Pre-eclampsia is a hypertensive disorder in pregnancy, which accounts for 10-15% of the maternal and perinatal mortality worldwide. Abnormal placental development and tissue hypoxia are its main etiologic factors. The present diagnostic methods of blood pressure monitoring and renal function evaluation are insufficient in the early detection of pre-eclampsia. Since molecular events portent well ahead of the disease onset, biomarker research for the early diagnosis of pre-eclampsia has recently generated ambitious clinical targets...

No abstract text is available yet for this article.

INTRODUCTION: While there is evidence for a relationship between cell-free fetal DNA (cffDNA) and parturition, questions remain regarding whether cffDNA could trigger a pro-inflammatory response on the pathway to parturition. We hypothesized that placental and/or fetal DNA stimulates toll-like receptor 9 (TLR9) leading to secretion of pro-inflammatory cytokines by macrophage cells. METHODS: Four in vitro DNA stimulation studies were performed using RAW 264.7 mouse peritoneal macrophage cells incubated in media containing the following DNA particles: an oligodeoxynucleotide (ODN2395), intact genomic DNA (from mouse placentas, fetuses and adult liver), mouse DNA complexed with DOTAP (a cationic liposome forming compound), and telomere-depleted mouse DNA...

OBJECTIVES: The objective of this study was to identify maternal characteristics associated with a failed cell-free DNA (cfDNA) test due to a low fetal fraction (FF). METHOD: Retrospective cohort study of women with singleton pregnancies who had cfDNA screening at 10-25 weeks gestation between October 2011 and January 2016. cfDNA screening was performed using methylation techniques until October 2013; thereafter, samples were run with massively parallel sequencing...

Wildlife health is of interest for public and animal health because wild animals have been identified as important sentinels for the surveillance for zoonotic pathogens. This work investigated Brucella spp., Coxiella burnetii, and Leptospira spp. infection seroprevalence in a free-ranging red deer population. The study was conducted in a fenced reserve with controlled hunting activity in central Spain with animals that did not have any contact with livestock. Sampling was performed at two time points before and 5 years after the implementation of new management measures, including a reduction in the red deer population in the reserve...

Term labor in humans is associated with increased oxidative stress (OS) -induced senescence and damages to amnion epithelial cells (AECs). Senescent fetal cells release alarmin high-mobility group box 1 (HMGB1) and cell-free fetal telomere fragments (cffTF) which can be carried by exosomes to other uterine tissues to produce parturition-associated inflammatory changes. This study characterized AEC-derived exosomes under normal and OS conditions and their packaging of HMGB1 and cffTF. Primary AECs were treated with either standard media or oxidative stress-induced media (exposure to cigarette smoke extract for 48h)...

Whole-genome sequencing (WGS) of maternal plasma cell-free DNA (cfDNA) can potentially evaluate all 24 chromosomes to identify abnormalities of the placenta, fetus, or pregnant woman. Current bioinformatics algorithms typically only report on chromosomes 21, 18, 13, X, and Y; sequencing results from other chromosomes may be masked. We hypothesized that by systematically analyzing WGS data from all chromosomes, we could identify rare autosomal trisomies (RATs) to improve understanding of feto-placental biology...

During pregnancy, cell-free DNA (cfDNA) in maternal blood encompasses a small percentage of cell-free fetal DNA (cffDNA), an easily accessible source for determination of fetal disease status in risk families through non-invasive procedures. In case of monogenic heritable disease, background maternal cfDNA prohibits direct observation of the maternally inherited allele. Non-invasive prenatal diagnostics (NIPD) of monogenic diseases therefore relies on parental haplotyping and statistical assessment of inherited alleles from cffDNA, techniques currently unavailable for routine clinical practice...

OBJECTIVE: To investigate factors associated with abnormal cell-free DNA (cfDNA) results for sex chromosomes (SC). Study Design This is a retrospective cohort study of abnormal cfDNA results for SC at a referral practice, from March 2013 to July 2015. CfDNA results were abnormal if they were positive for SC aneuploidy (SCA), inconclusive, or discordant with ultrasound (US) findings. Primary outcome was concordance with karyotype or postnatal evaluation. RESULTS: Of fifty abnormal cfDNA results for SC, 31 patients (62%) were positive for SCA, 13 (26%) were inconclusive, and 6 (12%) were sex-discordant on US...

OBJECTIVES: To evaluate the utility of noninvasive prenatal testing using cell-free circulating fetal DNA (cfDNA) in screening for the three main autosomal fetal trisomies in twin pregnancies. METHODS: CfDNA testing was offered to 492 patients with twin pregnancies without ultrasound anomalies as a first-line screening test or after serum screening in clinical practice. Data were collected prospectively and a retrospective analysis was performed. CfDNA analysis was performed by massively parallel sequencing...

From the discovery of cell-free fetal (cff)-DNA in 1997 so far, many studies have been performed on various aspects of cff-nucleic acid. It is undoubted that currently, invasive prenatal diagnosis progresses to the noninvasive test. However, there are many problems. One of the most challenging issues in this field is differentiation and detection of the small amount of cff-nucleic acid in maternal plasma. Many markers and methods have been used for this purpose. This review makes an attempt to review and compare the studies in the field...

No abstract text is available yet for this article.

Two recent studies demonstrated that array CGH and NGS allow identification of chromosomal abnormalities in fetal trophoblasts circulating in maternal blood. This remarkable breakthrough paves the way for an improved assay that supersedes the performance of non-invasive prenatal testing (NIPT) in cell-free fetal DNA. Furthermore, it is foreseeable to expand the use of this new genomic analysis in trophoblasts to uncover single gene mutations of clinical significance prenatally.

OBJECTIVE: The unique biological behavior of sex chromosomes has implications for cell-free DNA (cfDNA) testing. Our purpose is to predict the (1) false positive/negative rates of cfDNA testing consequent to fetoplacental mosaicism for any sex chromosome aneuploidies (SCA) and (2) positive predictive value (PPV) and negative predictive values of a high-risk and low-risk cfDNA result for any SCA. METHOD: This is a retrospective analysis of 67 030 chorionic villus sampling karyotypes, including fetoplacental mosaicism cases...

Maternal cell-free DNA (cfDNA) results that are discordant with the diagnostic fetal karyotype should prompt further investigation. If deeper analysis of the cfDNA results demonstrates a "saw-tooth" pattern characteristic of genome-wide imbalance, maternal malignancy is suggested. Identifying the maternal malignancy can, however, be difficult.