scholarly journals Is there a role for nuchal translucency in detection of rare chromosomal abnormalities in the era of non-invasive prenatal testing?

Author(s):  
Yan-Lin Li ◽  
Dong-Zhi Li
2021 ◽  
Author(s):  
Meiying Cai ◽  
Na Lin ◽  
Xuemei Chen ◽  
Ying Li ◽  
Min Lin ◽  
...  

Abstract Non-invasive prenatal testing (NIPT) is a fast, safe, and non-disruptive diagnostic method. At present, few studies have evaluated the screening efficiency of NIPT positive predictive value (PPV) in study subjects. Here, the results of NIPT in pregnant women were retrospectively analysed, and the detection rate, PPV and follow-up data were evaluated to determine its clinical value. A large multicentre study was conducted involving 52,855 pregnant women who received NIPT. Based on gestational age, amniotic fluid or umbilical cord blood were extracted for simultaneous karyotype and chromosome microarray analysis (CMA) in NIPT-positive patients. Among the 52,855 cases, 754 were NIPT-positive, with a positivity rate of 1.4%. Karyotype analysis and/or CMA confirmed 323 cases of chromosomal abnormalities, with a PPV of 45.1%. PPV of Trisomy 21 (T21), Trisomy 18 (T18), Trisomy 13 (T13), sex chromosomal aneuploidies (SCA) and copy number variations (CNV) were 78.9%, 35.3%, 22.2%, 36.9% and 32.9%, respectively. The PPV of T21, T18, and T13 increased with age whereas, the PPV of SCA and CNVs had little correlation with age. The PPV was significantly high in patients with advanced age along with an abnormal ultrasound.NIPT had a high PPV for T21, and a low PPV for T13 and T18, while screening for SCA and CNVs showed clinical significance. However, in case of NIPT screening for SCA and CNVs, simultaneous karyotype and CMA should be performed to increase the detection rates. Interventional prenatal diagnosis is still required in NIPT-positive cases to avoid false positives or unnecessary termination of pregnancy.


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.


2020 ◽  
Vol 56 (S1) ◽  
pp. 32-32
Author(s):  
I. Brown ◽  
S. Fernando ◽  
M. Menezes ◽  
F. Silva Costa ◽  
J. Ramkrishna ◽  
...  

2021 ◽  
Author(s):  
Justyna Anna Domaradzka ◽  
Marta Deperas ◽  
Ewa Obersztyn ◽  
Anna Kucińska-Chahwan ◽  
Nathalie Brison ◽  
...  

Abstract Background: Non-invasive prenatal testing (NIPT) is a rapidly developing and widely used method in the prenatal screening. Recently, the widespread use of the NIPT caused a neglecting of the limitations of this technology. Case presentation: The 38-year-old woman underwent amniocentesis because of a high risk of trisomy 2 revealed by the genome-wide Non-Invasive Prenatal Test (NIPT). The invasive prenatal diagnosis revealed the mosaicism for a small supernumerary marker chromosome sSMC derived from chromosome 2. Interphase fluorescence in situ hybridization (FISH) on uncultured amniocytes revealed three signals of centromere 2 in 30% of the cells. GTG-banded metaphases revealed abnormal karyotype (47,XX,+mar[21]/46,XX[19]) and was confirmed by array comparative genomic hybridization (aCGH). Cytogenetic analyses (FISH, aCGH, karyotype) on fetal skin biopsies were performed and confirmed the genomic gain of the centromeric region of chromosome 2. In the placenta, three cell lines were detected: a normal cell line, a cell line with trisomy 2 and a third one with only the sSMC.Conclusion: Whole-genome Non-Invasive Prenatal Testing allows not only the identification of common fetal trisomies but also diagnosis of rare chromosomal abnormalities. Especially in such cases, it is extremely important to perform not only NIPT verification on a sample of material other than trophoblast, but also to apply appropriate research methods. Such conduct allows detailed analysis of the detected aberration, thus appropriate clinical validity.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Alexander Scharf

Abstract Non-invasive prenatal testing (NIPT) is often erroneously received as a diagnostic procedure due to its high discriminatory power in the field of fetal trisomy 21 diagnosis (wording: “NIPT replaces amniocentesis”). Already a look at the methodology of NIPT (statistical gene dose comparison of a primarily maternofetal DNA mixture information at selected sites of the genome) easily reveals that NIPT cannot match the gold standard offered by cytogenetic and molecular genetic analysis procedures from the matrix of the entire human genome (origin: vital fetal cells), neither in diagnostic breadth nor in diagnostic depth. In fact, NIPT in fetal medicine in its current stage of development is a selective genetic search procedure, which can be applied in primary (without indication) or secondary (indication-related) screening. Thus, NIPT competes with established search procedures for this field. Here, the combined nuchal translucency (NT) test according to Nicolaides has become the worldwide standard since 2000. The strength of this procedure is its broad predictive power: NT addresses not only the area of genetics, but also the statistically 10 times more frequent structural fetal defects. Thus, NIPT and NT have large overlaps with each other in the field of classical cytogenetics, with slightly different weighting in the fine consideration. However, NIPT without a systematic accompanying ultrasound examination would mean a step back to the prenatal care level of the 1980s. In this respect, additional fine ultrasound should always be required in the professional application of NIPT. NIPT can thus complement NT in wide areas, but not completely replace it.


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