The hidden causes of pregnancy loss: a closer look.

Background: Unexpected pregnancy loss can be a traumatic experience for fertile couples. The aim of the study was to assess the nature and type of chromosomal variants involved in early and late pregnancy loss and provide couples an explanation on the cause of their pregnancy loss.

Methods: Investigations were conducted on 2928 pregnancy loss cases where products of conception (POC) samples could be retrieved for genetic analysis.

Next-generation variant exon screening: Moving forward in routine genetic disease investigations.

Purpose: Patients with genetic diseases often seek testing to reach a firm diagnosis. Based on clinical phenotypes, exome sequencing for small-nucleotide variations or array-based methods for copy-number variations (CNVs) are commonly offered to identify the underlying causative genetic variants. In this study, we investigated whether data from a standard ES test could be used to additionally identify pathogenic CNVs and increase diagnostic yield.

Unexpected Findings of Duchenne Muscular Dystrophy in Prenatal Screening of Chromosome Abnormality Based on Cell-Free Fetal DNA.

This study aims to assess the feasibility of detecting and diagnosing Duchenne muscular dystrophy (DMD) during prenatal screening for chromosome abnormalities using cell-free fetal DNA extracted from peripheral blood samples of pregnant women.Two pregnant women identified as high risk through noninvasive prenatal testing (NIPT) underwent amniocentesis to obtain fetal cells. Subsequent fetal chromosomal karyotyping was conducted, and genomic DNA from fetal cells was extracted for copy number variation sequencing (CNV-Seq) analysis, complemented by multiplex ligation-dependent probe amplification (MLPA) to detect deletions or duplications within the DMD gene.

[Expert consensus on the prenatal diagnosis and genetic counseling for uniparental disomy-related imprinting disorders].

Uniparental disomy (UPD)-related imprinting disorders are a group of congenital disorders which can lead to severe birth defects. Their molecular etiology is the occurrence of UPD in the genomic imprinting regions, which may cause disturbed expression of parent-of-origin imprinted genes. With the widespread applications of genetic testing techniques, the prenatal diagnosis of UPD-related imprinted diseases has gradually become clinical routines.

[Clinical and genetic analysis of ten Chinese pedigrees affected with 7q11.23 duplication syndrome].

Objective: To analyze the clinical and genetic characteristics of ten Chinese pedigrees affected with 7q11.23 duplication syndrome.

Methods: From December 2017 to January 2022, ten pedigrees diagnosed with 7q11.

[Clinical phenotype and genetic analysis of a patient with a heterozygous 6p25.3 deletion and partial trisomy 15q].

Objective: To investigate the clinical phenotype and genetic characteristics of a patient with a heterozygous 6p25.3 deletion and partial trisomy 15q.

Methods: A patient who had presented at the Genetics and Prenatal Diagnosis Center of the First Affiliated Hospital of Zhengzhou University on May 14, 2021 was selected as the study subject.

[The value of combined CNV-Seq and chromosomal karyotyping for the detection of amniocytic mosaicisms and a literature review].

Objective: To assess the value of combined copy number variation sequencing (CNV-seq) and chromosomal karyotyping for the diagnosis of amniocytic mosaicisms, in addition with a literature review.

Methods: Forty cases of amniocytic mosaicisms detected at the Genetic and Prenatal Diagnosis Center of the First Affiliated Hospital of Zhengzhou University from January 2018 to December 2021, in addition with 245 mosaicisms retrieved from 11 recent literature were evaluated in terms of detection rate, consistency rate, and pregnancy outcomes.

Results: The detection rate of amniocytic mosaicisms was 0.

[Analysis of genome copy number variations in fetuses with isolated ventricular septal defect and a literature review].

Objective: To assess the value of copy number variation sequencing (CNV-seq) for revealing the genetic etiology of fetuses with isolated ventricular septal defect (VSD).

Methods: From December 2017 to December 2020, 69 fetuses with isolated VSD were identified at the First Affiliated Hospital of Zhengzhou University. Meanwhile, 839 similar prenatal cases were selected from public databases including Wanfang data, Wanfang Medicine, and China National Knowledge Infrastructure (CNKI) by using keywords such as "Ventricular septal defect", "Copy number variation", and "Prenatal".

The uncertainty of copy number variants: pregnancy decisions and clinical follow-up.

Background: Next-generation sequencing for copy number variants is often used as a follow-up investigation of unusual fetal ultrasound results and is capable of detecting copy number variations with a resolution of ∼0.1 Mb. In a prenatal setting, observation and subsequent management of pregnancies with a fetal variant of uncertain significance remains problematic for counseling.

[Clinical and genetic analysis of a child with mosaic chromosome 8 trisomy syndrome].

Objective: To explore the genetic etiology of a child featuring recurrent oral ulcer.

Methods: Clinical data of the child was collected. Whole exome sequencing was carried out for her.

Estimate of genetic variants using CNV-Seq for fetuses with oligohydramnios or polyhydramnios.

Background: Oligohydramnios or polyhydramnios, is associated with chromosomal aberrations, particularly aneuploidy. However, its correlation with copy number variation (CNV) remains unclear.

Methods: We retrospectively analyzed 428 cases with an abnormal level of amniotic fluid, comprising of 139 cases of single ultrasound findings (SU group) and 289 cases of multiple ultrasound findings (MU group), by CNV sequencing (CNV-Seq) and followed their pregnancy outcomes.

[Genetic analysis and prenatal diagnosis for a Chinese pedigree affected with Bainbridge-Ropers syndrome].

Objective: To explore the clinical features and genetic basis for a child with Bainbridge-Ropers syndrome (BRPS).

Methods: Clinical data of the child were retrospectively analyzed. Copy number variation sequencing (CNV-seq) and trio based whole exome sequencing (trio-WES) were carried out.

[CNV-seq analysis of copy number variations in 217 fetuses with nasal bone dysplasia].

Objective: To assess the diagnostic value of copy number variation sequencing (CNV-seq) in the genetic etiology of fetuses with nasal bone dysplasia (NBD).

Methods: A total of 217 fetuses discovered with NBD from December 2017 to December 2020 were divided into the isolated NBD group and NBD combined with other anomalies group, for which copy number variations (CNVs) were analyzed.

Results: A total of 40 fetal abnormalities were detected in 217 cases, with an overall abnormal rate of 18.

[Analysis of chromosomal copy number variations among 163 fetuses with echogenic bowel by using CNV-seq technology].

Objective: To assess the value of low-depth whole-genome copy number variation sequencing (CNV-seq) for the analysis of chromosomal copy number variations among fetuses with echogenic bowel (EB).

Methods: A total of 163 fetuses were included in this study. Amniotic fluid (162 cases) or chorionic villi (1 case) were collected and subjected to CNV-seq for the analysis of CNVs.

[Analysis of a case with Mowat-Wilson syndrome due to nonsense variant of ZEB2 gene].

Objective: To explore the genetic basis for a girl with distinctive facial features, epilepsy, intellectual disability, chronic constipation and hypopigmentation of neck and upper extremities.

Methods: Whole exome sequencing was carried out for the proband. Candidate variant was verified by Sanger sequencing.

[Application of CNV-seq and chromosomal karyotyping in the prenatal diagnosis for carriers of balanced translocations].

Objective: To assess the value of copy number variation sequencing (CNV-seq) and karyotyping in the prenatal diagnosis for carriers of balanced translocations.

Methods: Clinical records of 135 amniocentesis samples of balanced translocation carriers undergoing simultaneous CNV-seq and karyotyping were analyzed. Chromosomal aberrations were defined as those can definitely lead to birth defects definitely, which included chromosomal numerical abnormality, large deletion/duplication and pathogenic copy number variations (pCNVs).

Novel Partial Exon 51 Deletion in the Duchenne Muscular Dystrophy Gene Identified Whole Exome Sequencing and Long-Read Whole-Genome Sequencing.

Duchenne muscular dystrophy (DMD), one of the most common progressive and severely disabling neuromuscular diseases in children, can be largely attributed to the loss of function of the gene on chromosome Xp21.2-p21.1.

[Clinical phenotype and genetic analysis of MECP2 duplication syndrome].

Objective: To analyze the clinical symptom and parental origin of patients with MECP2 duplication syndrome in order to provide a basis for genetic counseling and prenatal diagnosis.

Methods: Clinical symptoms of four patients who were diagnosed with MECP2 duplication syndrome by copy number variation sequencing (CNV-Seq) were reviewed. The maternal origin of the duplications were verified.

[Variant analysis of SEC23B gene in 4 families with congenital dyserythropoietic anemia].

Objective: To identify the pathogenic variants of 4 patients with hemolytic anemia of unknown cause.

Methods: Peripheral blood samples of the patients and their family members were collected to extract DNA. The coding region and splice region in all exons of gene of erythrocyte related diseases were analyzed by using target sequence capture and high-throughput sequencing technology.

[Prenatal diagnosis and family analysis of 22q11.2 microdeletion syndrome].

Objective: To analyze the prenatal diagnosis, parental verification and pregnancy outcome of 6 fetuses with 22q11.2 microdeletion syndrome.

Methods: Copy number variation sequencing (CNV-seq)and chromosomal microarray analysis (CMA) were carried out for the fetuses.