scholarly journals An enrichment method to increase cell-free fetal DNA fraction and significantly reduce false negatives and test failures for non-invasive prenatal screening: a feasibility study

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Ping Hu ◽  
Dong Liang ◽  
Yangyi Chen ◽  
Ying Lin ◽  
Fengchang Qiao ◽  
...  
Genes ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 15
Author(s):  
Luigi Carbone ◽  
Federica Cariati ◽  
Laura Sarno ◽  
Alessandro Conforti ◽  
Francesca Bagnulo ◽  
...  

Fetal aneuploidies are among the most common causes of miscarriages, perinatal mortality and neurodevelopmental impairment. During the last 70 years, many efforts have been made in order to improve prenatal diagnosis and prenatal screening of these conditions. Recently, the use of cell-free fetal DNA (cff-DNA) testing has been increasingly used in different countries, representing an opportunity for non-invasive prenatal screening of pregnant women. The aim of this narrative review is to describe the state of the art and the main strengths and limitations of this test for prenatal screening of fetal aneuploidies.


2021 ◽  
Vol 70 (1) ◽  
pp. 19-50
Author(s):  
Elena A. Kalashnikova ◽  
Andrey S. Glotov ◽  
Elena N. Andreyeva ◽  
Ilya Yu. Barkov ◽  
Galina Yu. Bobrovnik ◽  
...  

This review article offers an analysis of application of cell-free fetal DNA non-invasive prenatal screening test for chromosome abnormalities in the mothers blood in different countries. The diagnostic capacities of the method, its limitations, execution models and ethical aspects pertinent to its application are discussed. The data for the discordant results is shown and analyzed. The advantages of the genome-wide variant of cell-free fetal DNA analysis and the problems concerning its application in the mass screening are described. The main suggestion is to implement the contingent cell-free fetal DNA testing model for the common trisomies (for the chromosomes 21, 18 and 13) into the prenatal diagnostic screening programs in the Russian Federation. This novel model is based on the results of the mass combined first trimester prenatal screening in four federal subjects of the country completed by 2019 and is offered as an additional screening in the mid-level risk group (with cut-off from 1 : 100 to 1 : 500 or from 1 : 100 to 1 : 1000) defined according to the first trimester prenatal screening results. The basic requirements for the implementation of the contingent model in the Russian Federation are stated.


Author(s):  
Abhijeet Kumar ◽  
Madhusudan Dey ◽  
Devendra Arora

<p>Prenatal screening for chromosomal abnormalities has two components i.e. prenatal screening (maternal serum screening and cell-free fetal DNA screening) and prenatal diagnosis (chorionic villus sampling, amniocentesis, and cordocentesis). Prenatal testing in the past decade is evolving towards non-invasive methods to determine the chromosome abnormality disorders in the fetus without incurring the risk of miscarriage. Conventional tools for prenatal screening included maternal age, maternal serum markers, ultrasound marker (nuchal thickness), and their combinations. With the increased risk of screening test patients were offered diagnostic tests (chorionic villus sampling, amniocentesis, and cordocentesis). After the availability of noninvasive prenatal tests for commercial use in 2011, a great marketing drive is there to establish it as a master tool for prenatal testing. However various society guidelines i.e. ACOG, RCOG, and ISUOG have clearly stated that cell-free fetal DNA based noninvasive prenatal tests is a screening test, not a diagnostic test. In the succeeding paragraph, we will review current trends in the field of cell-free fetal DNA noninvasive prenatal tests and the relevance of invasive testing in the context of noninvasive prenatal tests. Noninvasive prenatal tests does not entirely replace invasive prenatal testing procedures. Positive noninvasive prenatal tests findings must be confirmed by diagnostic tests based on an invasive sample source, mainly chorionic villus sampling or amniocentesis due to false positive and false negative reports of cell-free fetal DNA based tests. Continuing research and development efforts are focused on overriding noninvasive prenatal tests limitations. Recent studies show that procedure-associated risks in the case of prenatal invasive testing are very low as compared to previous studies. Prenatal invasive testing will remain as the backbone of prenatal diagnostic testing until the limitation of noninvasive prenatal tests is overcome.</p>


2020 ◽  
Vol 19 (6) ◽  
pp. 124-132
Author(s):  
A.S. Olenev ◽  
◽  
E.E. Baranova ◽  
O.V. Sagaydak ◽  
A.M. Galaktionova ◽  
...  

Congenital malformations, chromosomal and monogenic disease play a significant role in perinatal mortality and child disability. According to the early prenatal screening results in the Russian Federation in 2018, the overall ratio of chromosomal anomaly prevalence is 1:250–1:300. Currently aneuploidy risk is calculated by using indirect biochemical and ultrasound markers, that have low sensitivity and specificity which can cause false positives and false negative results leading to unreasonable invasive procedures or missing chromosomal anomalies. It is well known that cell-free fetal DNA is detected in maternal blood. Whole‐genome sequencing based non-invasive prenatal testing (NIPT) can detect fetal chromosomal aneuploidy with high sensitivity as early as 10 weeks into pregnancy. The accuracy of determining fetal sex is also high: sensitivity and specificity are 98,9% and 99,9% respectively. Implementing molecular technology into clinical practice is required to improve prenatal diagnosis in the Russian Federation, icluding Moscow. Integration of NIPT to analyse cell-free fetal DNA will increase the efficiency of fetal chromosomal anomalies’ detection. However, there are some legal and ethical aspects to consider when integrating a new technology for wide-spread use. This review reveals arguable issues of NIPT integration into widespread clinical practice and possible ways of solving those issues. Key words: NIPT, noninvasive prenatal test, prenatal screening, fetal sex, invasive prenatal diagnosis, X-linked disease, chromosomal anomaly, chromosomal microarray analysis


2019 ◽  
Vol 19 (2) ◽  
pp. 105-111
Author(s):  
Nadia Shafei ◽  
Mohammad Saeed Hakhamaneshi ◽  
Massoud Houshmand ◽  
Siavash Gerayeshnejad ◽  
Fardin Fathi ◽  
...  

Background: Beta thalassemia is a common disorder with autosomal recessive inheritance. The most prenatal diagnostic methods are the invasive techniques that have the risk of miscarriage. Now the non-invasive methods will be gradually alternative for these invasive techniques. Objective: The aim of this study is to evaluate and compare the diagnostic value of two non-invasive diagnostic methods for fetal thalassemia using cell free fetal DNA (cff-DNA) and nucleated RBC (NRBC) in one sampling community. Methods: 10 ml of blood was taken in two k3EDTA tube from 32 pregnant women (mean of gestational age = 11 weeks), who themselves and their husbands had minor thalassemia. One tube was used to enrich NRBC and other was used for cff-DNA extraction. NRBCs were isolated by MACS method and immunohistochemistry; the genome of stained cells was amplified by multiple displacement amplification (MDA) procedure. These products were used as template in b-globin segments PCR. cff-DNA was extracted by THP method and 300 bp areas were recovered from the agarose gel as fetus DNA. These DNA were used as template in touch down PCR to amplify b-globin gen. The amplified b-globin segments were sequenced and the results compared with CVS resul. Results: The data showed that sensitivity and specificity of thalassemia diagnosis by NRBC were 100% and 92% respectively and sensitivity and specificity of thalassemia diagnosis by cff-DNA were 100% and 84% respectively. Conclusion: These methods with high sensitivity can be used as screening test but due to their lower specificity than CVS, they cannot be used as diagnostic test.


2015 ◽  
Vol 43 (2) ◽  
pp. 228-240 ◽  
Author(s):  
Rachel Rebouché

A regulatory moment for prenatal health care is here. An increasing amount of legislative attention has concentrated on the decisions pregnant women make after prenatal testing. The impetus for this legislation is a new non-invasive prenatal genetic test (NIPT). From the beginning of pregnancy, cell-free fetal DNA travels across the placental lining into the mother’s bloodstream, increasing in quantity as the pregnancy progresses. Laboratories can now analyze that DNA for chromosomal abnormalities and for fetal sex at 10 weeks of gestation. NIPT, which relies on a sample of the pregnant woman’s blood, is painless, occurs early in pregnancy, and is available for clinical and commercial use. In 2013, major health insurance plans began to cover NIPT for certain populations of women, such as women over 35 years old. And private companies have started marketing prenatal testing kits directly to consumers, who return a blood sample from the prospective mother to a company laboratory.


2012 ◽  
Vol 15 (Supplement) ◽  
pp. 17-26 ◽  
Author(s):  
Neil D. Avent ◽  
A Webb ◽  
TE Madgett ◽  
T Miran ◽  
K Sillence ◽  
...  

ABSTRACT Current invasive procedures [amniocentesis and chorionic villus sampling (CVS)] pose a risk to mother and fetus and such diagnostic procedures are available only to high risk pregnancies limiting aneuploidy detection rate. This review seeks to highlight the necessity of investing in non invasive prenatal diagnosis (NIPD) and how NIPD would improve patient safety and detection rate as well as allowing detection earlier in pregnancy. Non invasive prenatal diagnosis can take either a proteomics approach or nucleic acid-based approach; this review focuses on the latter. Since the discovery of cell free fetal DNA (cffDNA) and fetal RNA in maternal plasma, procedures have been developed for detection for monogenic traits and for some have become well established (e.g., RHD blood group status). However, NIPD of aneuploidies remains technically challenging. This review examines currently published literature evaluating techniques and approaches that have been suggested and developed for aneuploidy detection, highlighting their advantages and limitations and areas for further research.


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