Non-Invasive Fetal RHD Exon 7 and Exon 10 Genotyping Using Real-Time PCR Testing of Fetal DNA in Maternal Plasma

2005 ◽  
Vol 20 (4) ◽  
pp. 275-280 ◽  
Author(s):  
Ilona Hromadnikova ◽  
Lenka Vechetova ◽  
Klara Vesela ◽  
Blanka Benesova ◽  
Jindrich Doucha ◽  
...  
2005 ◽  
Vol 53 (3) ◽  
pp. 301-305 ◽  
Author(s):  
Ilona Hromadnikova ◽  
Lenka Vechetova ◽  
Klara Vesela ◽  
Blanka Benesova ◽  
Jindrich Doucha ◽  
...  

We assessed the feasibility of fetal RHD and RHCE genotyping by analysis of DNA extracted from plasma samples of RhD-negative pregnant women using real-time PCR and primers and probes targeted toward RHD and RHCE genes. We analyzed 45 pregnant women in the 11th to 40th weeks of pregnancy and correlated the results with serological analysis of cord blood after delivery. Non-invasive prenatal fetal RHD exon 7, RHD exon 10, RHCE exon 2 (C allele), and RHCE exon 5 (E allele) genotyping analysis of maternal plasma samples was correctly performed in 45 out of 45 RhD-negative pregnant women delivering 24 RhD-, 17 RhC-, and 7 RhE-positive newborns. Detection of fetal RHD and the C and E alleles of RHCE gene from maternal plasma is highly accurate and enables implementation into clinical routine. We recommend performing fetal RHD and RHCE genotyping together with fetal sex determination in alloimmunized D-negative pregnancies at risk of hemolytic disease of the newborn. In case of D-negative fetus, amplification of another paternally inherited allele (SRY and/or RhC and/or RhE positivity) proves the presence of fetal DNA in maternal circulation.


Author(s):  
Sherry Sze Yee Ho ◽  
Angela Barrett ◽  
Henna Thadani ◽  
Cecille Laureano Asibal ◽  
Evelyn Siew-Chuan Koay ◽  
...  

AbstractPrenatal diagnosis of sex-linked disorders requires invasive procedures, carrying a risk of miscarriage of up to 1%. Cell-free fetal DNA (cffDNA) present in cell-free DNA (cfDNA) from maternal plasma offers a non-invasive source of fetal genetic material for analysis. Detection of Y-chromosome sequences in cfDNA indicates presence of a male fetus; in the absence of a Y-chromosome signal a female fetus is inferred. We aimed to validate the clinical utility of insertion-deletion polymorphisms (INDELs) to confirm presence of a female fetus using cffDNA.Quantitative real-time PCR (qPCR) for the Y-chromosome-specific sequence,Fetal sex was correctly determined in 77/82 (93.9%) cfDNA samples.We have validated a non-invasive prenatal test to confirm fetal sex as early as 6 gestational weeks using cffDNA from maternal plasma.


Diagnostics ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 564
Author(s):  
Jana Bohmova ◽  
Marek Lubusky ◽  
Iva Holuskova ◽  
Martina Studnickova ◽  
Romana Kratochvilova ◽  
...  

Noninvasive fetal RHD genotyping is an important tool for predicting RhD incompatibility between a pregnant woman and a fetus. This study aimed to assess a methodological approach other than the commonly used one for noninvasive fetal RHD genotyping on a representative set of RhD-negative pregnant women. The methodology must be accurate, reliable, and broadly available for implementation into routine clinical practice. A total of 337 RhD-negative pregnant women from the Czech Republic region were tested in this study. The fetal RHD genotype was assessed using two methods: real-time PCR and endpoint quantitative fluorescent (QF) PCR. We used exon-7-specific primers from the RHD gene, along with internal controls. Plasma samples were analyzed and measured in four/two parallel reactions to determine the accuracy of the RHD genotyping. The RHD genotype was verified using DNA analysis from a newborn buccal swab. Both methods showed an excellent ability to predict the RHD genotype. Real-time PCR achieved its greatest accuracy of 98.6% (97.1% sensitivity and 100% specificity (95% CI)) if all four PCRs were positive/negative. The QF PCR method also achieved its greatest accuracy of 99.4% (100% sensitivity and 98.6% specificity (95% CI)) if all the measurements were positive/negative. Both real-time PCR and QF PCR were reliable methods for precisely assessing the fetal RHD allele from the plasma of RhD-negative pregnant women.


Author(s):  
Wenqian Song ◽  
Shihang Zhou ◽  
Linnan Shao ◽  
Ni Wang ◽  
Lingzi Pan ◽  
...  

AbstractFetal-maternal ABO incompatibility is a frequent cause of hemolytic disease of the fetus and newborn (HDFN). The routine serological testing of maternal IgG antibody level to predict HDFN shows low reliability. Non-invasive fetal ABO genotyping could provide a new avenue for predicting ABO-HDFN in early pregnancy. The aim of our study is to investigate the feasibility of fetal ABO genotyping in maternal plasma with real-time PCR.Plasma samples were collected from a total of 73 blood group O pregnant women between 12 and 25 weeks of gestation, and then DNA was extracted from the maternal plasma containing cell-free fetal DNA (cffDNA). TaqMan-based real-time PCR was performed after methylation-sensitive restriction enzyme to detect hypermethylatedThe fetalWe have developed a rapid and reliable protocol for fetal ABO genotyping in maternal plasma using real-time PCR. This protocol is suitable for routine prenatal diagnose of HDFN and forensic analysis.


Author(s):  
Najmeh Davoodian ◽  
Ali Kadivar ◽  
Heidar Heidari Khoie ◽  
Sima Hematian Khayat ◽  
Mahboobeh Heidari Nasirabadi

Background and Aims: New advances in the use of cell-free fetal DNA (cffDNA) in maternal plasma of pregnant women has provided the possibility of applying cffDNA in prenatal diagnosis as a non-invasive method. One of the applications of prenatal diagnosis is fetal gender determination. Early prenatal determination of fetal sex is required for pregnant women at risk of X-linked and some endocrine diseases. The present study was carried out to perform an efficient polymerase chain reaction (PCR) method in order to improve sensitivity, specificity and accuracy of non-invasive fetal gender detection using fetal DNA in maternal plasma during 8th -12th weeks of pregnancy. Materials and Methods: Thirty-five pregnant women with 8 to 12 weeks of pregnancy were selected for prenatal fetal sex determination. Maternal peripheral blood was collected and cffDNA was extracted from 3-ml of maternal plasma. Two multi copy Y-chromosome-specific region (DYS and DAZ) and a single copy gene (SRY) were amplified by real-time quantitative PCR. Amplification was labeled as positive, negative, or inconclusive according to a stringent algorithm. Results: Using this method, the sensitivity and specificity of the real-time PCR assay was 100% and 93.8% for prenatal fetal sex detection, respectively. Conclusions: It is concluded that fetal sex can be determined with a high level of accuracy by our algorithm, after 8 weeks of gestation with cffDNA analysis.


2003 ◽  
Vol 23 (3) ◽  
pp. 235-238 ◽  
Author(s):  
Ilona Hromadnikova ◽  
Bela Houbova ◽  
Dana Hridelova ◽  
Sona Voslarova ◽  
Josef Kofer ◽  
...  

2009 ◽  
Vol 39 (7) ◽  
pp. 607-617 ◽  
Author(s):  
X. D. Wang ◽  
B. L. Wang ◽  
S. L. Ye ◽  
Y. Q. Liao ◽  
L. F. Wang ◽  
...  

2004 ◽  
Vol 50 (3) ◽  
pp. 516-521 ◽  
Author(s):  
Kirby L Johnson ◽  
Kimberly A Dukes ◽  
John Vidaver ◽  
Erik S LeShane ◽  
Idania Ramirez ◽  
...  

Abstract Background: Analysis of fetal DNA from maternal plasma by PCR offers great potential for noninvasive prenatal genetic diagnosis. To further evaluate this potential, we developed and validated a standard protocol to determine whether fetal DNA sequences could be reproducibly amplified and measured across multiple laboratories in a common set of specimens. Methods: Each of five participating centers in a National Institute of Child Health and Human Development consortium collected 20 mL of peripheral blood from 20 pregnant women between 10 and 20 weeks of gestation. The plasma fraction was separated according to a common protocol, divided, and frozen in five aliquots. One aliquot was shipped to each participating laboratory, where DNA was extracted according to a standard protocol. All plasma samples (n = 100) were then analyzed blindly for the presence and quantity of total DNA (GAPDH) and male fetal DNA (SRY) by real-time PCR. Genomic DNA was isolated from female and male cells at one center, quantified, and shipped to the others to serve as calibrators for GAPDH and SRY, respectively. Results: The amplification of known quantities of DNA was consistent among all centers. The mean quantity of male DNA amplified from maternal plasma when the fetus was male ranged from 51 to 228 genome equivalents (GE)/mL. Qualitative concordance was found overall among centers. The sensitivity of the assay for detection of male DNA when the fetus was male varied from 31% to 97% among centers. Specificity was more consistent (93–100%) with only four false-positive results obtained across the entire study. Conclusions: All centers were able to consistently amplify frozen and shipped DNA. The PCR procedure used here is reliable and reproducible. Centers that extracted and amplified more DNA per milliliter of maternal plasma had superior sensitivities of Y chromosome sequence detection. The specificity of the assay was more consistent among centers. A robust and thoroughly optimized protocol for the extraction of DNA from maternal plasma is needed to make testing of fetal DNA in maternal plasma a clinically relevant analytical tool.


2008 ◽  
Vol 54 (10) ◽  
pp. 1664-1672 ◽  
Author(s):  
Fiona M F Lun ◽  
Rossa W K Chiu ◽  
K C Allen Chan ◽  
Tak Yeung Leung ◽  
Tze Kin Lau ◽  
...  

Abstract 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. Methods: We first determined whether microfluidics digital PCR, real-time PCR, and mass spectrometry produced different estimates of male-DNA concentrations in artificial mixtures of male and female DNA. We then focused on comparing the imprecision of microfluidics digital PCR with that of a well-established nondigital PCR assay for measuring male fetal DNA in maternal plasma. Results: Of the tested platforms, microfluidics digital PCR demonstrated the least quantitative bias for measuring the fractional concentration of male DNA. This assay had a lower imprecision and higher clinical sensitivity compared with nondigital real-time PCR. With the ZFY/ZFX assay on the microfluidics digital PCR platform, the median fractional concentration of fetal DNA in maternal plasma was ≥2 times higher for all 3 trimesters of pregnancy than previously reported. Conclusions: Microfluidics digital PCR represents an improvement over previous methods for quantifying fetal DNA in maternal plasma, enabling diagnostic and research applications requiring precise quantification. This approach may also impact other diagnostic applications of plasma nucleic acids, e.g., in oncology and transplantation.


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