Prenatal diagnosis and early childhood outcome of fetuses with extremely large nuchal translucency.

Objective: To evaluate the prenatal and perinatal outcome of fetuses with extremely large nuchal translucency (eNT) thickness (≥ 6.5 mm).

Methods: 193 (0.

Application of exome sequencing for prenatal diagnosis of fetal structural anomalies: clinical experience and lessons learned from a cohort of 1618 fetuses.

Background: Exome sequencing (ES) is becoming more widely available in prenatal diagnosis. However, data on its clinical utility and integration into clinical management remain limited in practice. Herein, we report our experience implementing prenatal ES (pES) in a large cohort of fetuses with anomalies detected by ultrasonography using a hospital-based in-house multidisciplinary team (MDT) facilitated by a three-step genotype-driven followed by phenotype-driven analysis framework.

Contribution of maternal mosaicism to false-positive chromosome X loss associated with noninvasive prenatal testing.

Objective: To report the frequency of maternal mosaicism contributing to false-positive chromosome X loss associated with noninvasive prenatal testing (NIPT) at a single center.

Methods: Pregnancies undergone NIPT using massively parallel sequencing at Guangzhou Women and Children's Medical Center between February 2015 and May 2020 were included in this study. Fetal karyotyping, quantitative fluorescence PCR (QF-PCR) or microarray analysis was provided to patients with abnormal sex chromosomal aneuploidy (SCA) results for confirmatory testing, and QF-PCR was also employed to detect maternal sex chromosome status.

Evaluation of the Z-score accuracy of noninvasive prenatal testing for fetal trisomies 13, 18 and 21 at a single center.

Objective: To assess the correlation between Z-scores of positive noninvasive prenatal testing (NIPT) results and the positive predictive value (PPV) of NIPT.

Methods: Pregnancies with positive NIPT results at Guangzhou Women and Children's Medical Centre between July 2017 and May 2020 were included in this study. Fetal karyotyping or microarray analysis was provided to patients with abnormal NIPT results for confirmatory testing.

[Clinical and genetic analysis of three pediatric patients with 15q24 microdeletion syndrome].

Objective: To explore the genetic basis for three patients with development delay and to correlate their clinical phenotypes with genetic findings.

Methods: The karyotypes of the probands and their parents were analyzed by conventional G-banding. Chromosomal microarray analysis (CMA) was used to detect microdeletion and microduplication.

Pregnancy outcome of autosomal aneuploidies other than common trisomies detected by noninvasive prenatal testing in routine clinical practice.

Objective: The objective of the study is to report the incidence and pregnancy outcome of autosomal aneuploidies other than common trisomies 21, 18, and 13 detected by noninvasive prenatal testing (NIPT) at a single center.

Methods: Pregnant women undergoing NIPT from February 2015 to January 2018 in our center were offered expanded screening to include rare autosomal aneuploidies. Aneuploidies included extra copy chromosomes (most likely trisomies) and decreased copy chromosomes (most likely monosomies).

Chromosomal polymorphisms are independently associated with multinucleated embryo formation.

Purpose: The purpose of this study is to explore the factors associated with embryo multinucleation, particularly focused on the influence of parental chromosomal polymorphisms in embryo multinucleation.

Methods: This is a retrospective case-control study involving 1260 infertile couples undergoing their first IVF/ICSI cycles. Couples were screened for abnormalities in their karyotype and were evaluated for blastomere persistence of multinucleation.

The prevalence of non-detectable chromosomal abnormalities by QF-PCR in amniocentesis for certain referral indications: experience at a mainland Chinese hospital.

Purpose: To study the prevalence of non-detectable chromosomal abnormalities by quantitative fluorescent polymerase chain reaction (QF-PCR) in a Chinese population referred for amniocentesis.

Methods: The karyotype results were reviewed in 8,466 amniotic fluid cultures performed for positive fetal Down syndrome screening or advanced maternal age between January 2002 and June 2012. The karyotype results were classified as detectable or not detectable by QF-PCR, using the assumption that all tests were conducted by this rapid molecular method.

[Dandy-walker syndrome and microdeletions on chromosome 7].

Objective: To investigate genetic etiology of Dandy-Walker syndrome with array-based comparative genomic hybridization (array-CGH).

Methods: Eight fetuses with Dandy-Walker malformations but normal karyotypes by conventional cytogenetic technique were selected. DNA samples were extracted and hybridized with Affymetrix cytogenetic 2.

[Application of fluorescence in situ hybridization to prenatal diagnosis of aneuploidy in 110 uncultured amniotic fluid samples].

Objective: To optimize the prenatal diagnosis platform by using domestically made fluorescence in situ hybridization(FISH) kit and to explore the clinical application of FISH to rapid prenatal diagnosis of a wide range of chromosomal abnormalities.

Methods: Amniotic fluid samples from 110 pregnant women were studied with the rapid prenatal diagnosis method of FISH and the conventional cell culture method of karyotyping, the results from both methods were compared.

Results: Four cases of trisomy 21, 1 case of trisomy 18, 58 cases of 46, XX, and 47 cases of 46, XY were detected by FISH in the 110 amniotic fluid samples.

[Application of array-based comparative genomic hybridization in precise diagnosis of unbalanced chromosome aberration].

Objective: To evaluate the method of array-based comparative genomic hybridization (array-CGH) in identifying unbalanced chromosome aberrations.

Methods: Four cases that could not be diagnosed by conventional cytogenetic technique were selected to undergo array-CGH analysis. DNA samples were extracted and hybridized with the Affymetrix SNP 6.

[Application of spectral karyotyping in diagnosis and prenatal diagnosis of the marker chromosome].

Objective: To determine the value of spectral karyotyping(SKY) in identification of the marker chromosome.

Methods: Selected six cases that could not be identified in clinic were studied, using samples of peripheral blood from four cases, and samples of amonic fluid and fetal cord blood for prenatal diagnosis in two cases were investigated. All cases were analyzed with the routine SKY method, and the results with the SKY View software.

[Application of spectral karyotyping in diagnosis of complex chromosome aberration].

Objective: To determine the value of spectral karyotyping (SKY) to identify the complex chromosome aberration.

Methods: Four cases were selected that can not be identified by standard cytogenetic techniques. The chromosome specimens were detected by the routine SKY method, and the results were analyzed by the SKY View software.

[Polymorphisms analysis of short tandem repeat loci D21S1433, D21S1442, D21S1444, D21S2051 in Guangdong Han nationality in China].

Objective: To investigate the polymorphic distribution of short tandem repeat (STR) sequences D21S1433, D21S1442, D21S1444, D21S2051 in Guangdong Han nationality in China.

Methods: Using quantitative fluorescens PCR technology, the authors analyzed 200 unrelated samples to acknowledge the allele frequency, heterozygosity and other genetic information.

Results: D21S1433, D21S1442, D21S1444, D21S2051 were tested in 200 samples, which were tested to be statistical according to Hardy-Weinberg equilibrium (P> 0.

Application of real-time fluorescence quantitative PCR to rapid molecular detection of Down's syndrome.

Objective: To develop a rapid and reliable technique for the detection of Down's syndrome.

Methods: The peripheral blood samples were collected from twenty-five Down's syndrome patients and fifty normal individuals. Four polymorphic loci on chromosomes 21, 1, 19 were amplified by real-time fluorescence quantitative PCR, and then four pairs of deltaCt values were analytically compared between the two groups.

[Studies on safety of cordocentesis guided by transabdominal ultrasound for prenatal diagnosis].

Objective: To assess the safety and efficacy of diagnostic cordocentesis during pregnancy.

Methods: During March 1990 to June 2003, 2403 consecutive cordocenteses were performed under transabdominal ultrasound guidance at Guangzhou Women and Children's Hospital. The results of each procedure was prospectively collected and subsequently analysed in terms of operational complications and pregnancy outcomes.