scholarly journals Genetic Analysis in Fetal Skeletal Dysplasias by Trio Whole-Exome Sequencing

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Kai Yang ◽  
Ming Shen ◽  
Yousheng Yan ◽  
Ya Tan ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Autosomal Recessive ◽  
Clinical Manifestations ◽  
Autosomal Recessive Inheritance ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Skeletal Dysplasias ◽  
Whole Exome ◽  
Quantitative Fluorescence

Skeletal dysplasias (SDs) comprise a series of severe congenital disorders that have strong clinical heterogeneity and usually attribute to diverse genetic variations. The pathogenesis of more than half of SDs remains unclear. Additionally, the clinical manifestations of fetal SDs are ambiguous, which poses a big challenge for accurate diagnosis. In this study, eight unrelated families with fetal SD were recruited and subjected to sequential tests including chromosomal karyotyping, chromosomal microarray analysis (CMA), and trio whole-exome sequencing (WES). Sanger sequencing and quantitative fluorescence PCR (QF-PCR) were performed as affirmative experiments. In six families, a total of six pathogenic/likely pathogenic variations were identified in four genes including SLC26A2, FGFR3, FLNB, and TMEM38B. These variations caused disorders following autosomal dominant or autosomal recessive inheritance patterns, respectively. The results provided reliable evidence for the subsequent genetic counseling and reproductive options to these families. With its advantage in variation calling and interpreting, trio WES is a promising strategy for the investigation of fetal SDs in cases with normal karyotyping and CMA results. It has considerable prospects to be utilized in prenatal diagnosis.

Whole Exome Sequencing of Six Chinese Families With Hereditary Non-Syndromic Hearing Loss: A Genetic Etiology Study

2020 ◽  
Author(s):  
Pengfei Liang ◽  
Fengping Chen ◽  
Shujuan Wang ◽  
Qiong Li ◽  
Wei Li ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Sanger Sequencing ◽  
Large Scale ◽  
Autosomal Recessive ◽  
Autosomal Recessive Inheritance ◽  
Chinese Families ◽  
Whole Exome ◽  
Syndromic Hearing Loss

Abstract Background: Hereditary non-syndromic hearing loss (NSHL) has a high genetic heterogeneity with >152 genes identified as associated molecular causes. The present study aimed to detect the possible damaging variants of the deaf probands from six unrelated Chinese families.Methods: After excluding the mutations in the most common genes, GJB2 and SLC26A4, 12 probands with prelingual deafness and autosomal recessive inheritance were evaluated by whole-exome sequencing (WES). All the candidate variants were verified by Sanger sequencing in all patients and their parents.Results: Biallelic mutations were identified in all deaf patients. Among these six families, 10 potentially causative mutations, including 3 reported and 7 novel mutations, in 3 different deafness-associated autosomal recessive (DFNB) genes (MYO15A, COL11A2, and CDH23) were identified. The mutations in MYO15A were frequent with 7/10 candidate variants. Sanger sequencing confirmed that these mutations segregated with the hearing loss of each family.Conclusions: Next-generation sequencing (NGS) approach becomes more cost-effective and efficient when analyzing large-scale genes compared to the conventional polymerase chain reaction-based Sanger sequencing, which is often used to screen common deafness-related genes. The current findings further extend the mutation spectrum of hearing loss in the Chinese population, which has a positive significance for genetic counseling.

scholarly journals Identification of two novel pathogenic variants of PIBF1 by whole exome sequencing in a 2-year-old boy with Joubert syndrome

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Yue Shen ◽  
Hao Wang ◽  
Zhimin Liu ◽  
Minna Luo ◽  
Siyu Ma ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Autosomal Recessive ◽  
Autosomal Recessive Disorder ◽  
Autosomal Recessive Inheritance ◽  
Joubert Syndrome ◽  
Causative Gene ◽  
Pathogenic Variants ◽  
Whole Exome ◽  
Syndrome Individual

Abstract Background Joubert syndrome (OMIM 213300) is an autosomal recessive disorder with gene heterogeneity. Causal genes and their variants have been identified by sequencing or other technologies for Joubert syndrome subtypes. Case presentation A two-year-old boy was diagnosed with Joubert syndrome by global development delay and molar tooth sign of mid-brain. Whole exome sequencing was performed to detect the causative gene variants in this individual, and the candidate pathogenic variants were verified by Sanger sequencing. We identified two pathogenic variants (NM_006346.2: c.1147delC and c.1054A > G) of PIBF1 in this Joubert syndrome individual, which is consistent with the mode of autosomal recessive inheritance. Conclusion In this study, we identified two novel pathogenic variants in PIBF1 in a Joubert syndrome individual using whole exome sequencing, thereby expanding the PIBF1 pathogenic variant spectrum of Joubert syndrome.

scholarly journals Whole Exome Sequencing Facilitated the Identification of a Mosaic Small Supernumerary Marker Chromosome (sSMC)

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Huan-xia Xing ◽  
Peng-bin Li ◽  
Li-min Cui ◽  
Jian-ye Jiang ◽  
Ning-ning Hu ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Extended Family ◽  
Phenotypic Variability ◽  
Marker Chromosome ◽  
Chromosome 8 ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Chromosomal Anomalies ◽  
Whole Exome

Small supernumerary marker chromosomes (sSMCs) are a group of rare chromosomal anomalies, which pose challenges in the clinical practice of prenatal diagnosis and genetic counseling. This study enrolled an extended family with an underage male patient displaying infantile seizures, intellectual disability, and retarded speech and psychomotor function. A series of multiplatform genetic detections was conducted to explore the diagnostic variation. Whole exome sequencing (WES) and chromosomal microarray analysis (CMA) indicated a mosaic sSMC derived from the pericentromeric region of chromosome 8 in the patient, which was confirmed using cytogenetic methods. The proband and his mother, who carried this mosaic variant, exhibited strong phenotypic variability. We also ruled out the pathogenicity of a KDM5C variant by extended validation. Our results emphasized the capacity of WES to detect mosaic SMCs and the importance of mosaic ratios in the appearance and severity of symptomatic phenotypes.

Whole Exome Sequencing of Six Chinese Families with Hereditary Non-syndromic Hearing Loss

2021 ◽  
Author(s):  
Pengfei Liang ◽  
Fengping Chen ◽  
Shujuan Wang ◽  
Qiong Li ◽  
Wei Li ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Sanger Sequencing ◽  
Large Scale ◽  
Autosomal Recessive ◽  
Autosomal Recessive Inheritance ◽  
Chinese Families ◽  
Whole Exome ◽  
Syndromic Hearing Loss

Abstract Background: Hereditary non-syndromic hearing loss (NSHL) has a high genetic heterogeneity with >152 genes identified as associated molecular causes. The present study aimed to detect the possible damaging variants of the deaf probands from six unrelated Chinese families.Methods: After excluding the mutations in the most common genes, GJB2 and SLC26A4, 12 probands with prelingual deafness and autosomal recessive inheritance were evaluated by whole-exome sequencing (WES). All the candidate variants were verified by Sanger sequencing in all patients and their parents.Results:Biallelic mutations were identified in all deaf patients. Among these six families, 10 potentially causative mutations, including 3 reported and 7 novel mutations, in 3 different deafness-associated autosomal recessive (DFNB) genes (MYO15A, COL11A2, and CDH23) were identified. The mutations in MYO15A were frequent with 7/10 candidate variants. Sanger sequencing confirmed that these mutations segregated with the hearing loss of each family.Conclusions:Next-generation sequencing (NGS) approach becomes more cost-effective and efficient when analyzing large-scale genes compared to the conventional polymerase chain reaction-based Sanger sequencing, which is often used to screen common deafness-related genes. The current findings further extend the mutation spectrum of hearing loss in the Chinese population, which has a positive significance for genetic counseling.

The Promise of Whole-exome Sequencing for Prenatal Genetic Diagnosis

2020 ◽  
Vol 17 (1) ◽  
pp. 25-31
Author(s):  
Jiun Kang
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Genetic Disorders ◽  
Genetic Diagnosis ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Prognostic Information ◽  
Prenatal Genetic Diagnosis ◽  
Whole Exome ◽  
Nextgeneration Sequencing

Prenatal genetic diagnosis provides information for pregnancy and perinatal decision- making and management. Cytogenetic testing methods, including chromosomal microarray analysis and gene panels, have evolved to become a part of routine laboratory testing, providing valuable diagnostic and prognostic information for prenatal diagnoses. Despite this progress, however, cytogenetic analyses are limited by their resolution and diagnosis is only possible in around 40% of the dysmorphic fetuses. The advent of nextgeneration sequencing (NGS), whole-genome sequencing or whole-exome sequencing has revolutionized prenatal diagnosis and fetal medicine. These technologies have improved the identification of genetic disorders in fetuses with structural abnormalities and provide valuable diagnostic and prognostic information for the detection of genomic defects. Here, the potential future of prenatal genetic diagnosis, including a move toward NGS technologies, is discussed.

scholarly journals The Application of Late Amniocentesis: A Retrospective Study in a Tertiary Fetal Medicine Center in China

2020 ◽  
Author(s):  
Yingting Li ◽  
Huanchen Yan ◽  
Jingsi Chen ◽  
Fei Chen ◽  
Wei Jian ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Copy Number ◽  
Genetic Test ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Test Results ◽  
Whole Exome ◽  
Genetic Test Results

Abstract Background: To assess the indications and complications of late amniocentesis, and the advantage of advanced genetic test results in a tertiary university fetal medical medicine unit.Methods: In this retrospective study, women that underwent amniocentesis at 24+0 to 39+4 weeks, between January 2014 and December 2019, were recruited. Indications, complications, genetic test results, and pregnancy outcomes were reported for each pregnancy. Information was retrieved from patient medical records, checked by research staff, and analyzed. Results: Of the 1277 women (1311 fetuses) included, late detected sonographic abnormalities (86.2%) were the most common indication. The overall preterm birth and intrauterine demise rate were 2.6% and 1.2%, respectively, after amniocentesis. Sixty-six fetuses with aneuploidy (5.1%) and sixty-seven fetuses with pathogenic copy number variations (5.1%) were identified by chromosomal microarray analysis. One pathogenic copy number variation was detected by whole-exome sequencing. The maximal diagnostic yield (36.1%) was in the subgroup of fetuses with the abnormal noninvasive prenatal test, following by multiple abnormalities (23.8%). And 35.8% of the pregnancies were finally terminated.Conclusions: Due to the high detection rates of advanced genetic technologies and safety of the invasive procedure, it is reasonable to recommend late amniocentesis as an effective and credible method to detect late-onset fetal abnormalities. However, chromosomal microarray and whole-exome sequencing may result in uncertain results like variants of uncertain significance. Therefore, comprehensive genetic counseling is necessary.

scholarly journals Molecular Diagnostic Yield of Chromosomal Microarray Analysis and Whole-Exome Sequencing in Children With Autism Spectrum Disorder

JAMA ◽  
2015 ◽  
Vol 314 (9) ◽  
pp. 895 ◽  
Author(s):  
Kristiina Tammimies ◽  
Christian R. Marshall ◽  
Susan Walker ◽  
Gaganjot Kaur ◽  
Bhooma Thiruvahindrapuram ◽  
...  
Keyword(s):  
Autism Spectrum Disorder ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Diagnostic Yield ◽  
Children With Autism ◽  
Autism Spectrum ◽  
Molecular Diagnostic ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Whole Exome

scholarly journals Facial cleft? The first case of manitoba‐oculo‐tricho‐anal syndrome with novel mutations in China: a case report

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shuchen Gu ◽  
Yimin Khoong ◽  
Xin Huang ◽  
Tao Zan
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Clinical Manifestations ◽  
Sporadic Case ◽  
Facial Cleft ◽  
Ocular Manifestations ◽  
First Case ◽  
Whole Exome ◽  
Chinese Girl ◽  
Low Prevalence

Abstract Background Manitoba-oculo-tricho-anal (MOTA) syndrome is a rare syndrome with only 27 cases reported worldwide so far, but none was reported in the population of Eastern Asia. Such extremely low prevalence might be contributed by misdiagnosis due to its similarities in ocular manifestations with facial cleft. In our study, we discovered the first case of MOTA syndrome in the population of China, with 2 novel FRAS1 related extracellular matrix 1 (FREM1) gene stop-gain mutations confirmed by whole exome sequencing. Case presentation A 12-year-old Chinese girl presented with facial cleft-like deformities including aberrant hairline, blepharon-coloboma and broad bifid nose since birth. Whole exome sequencing resulted in the identification of 2 novel stop-gain mutations in the FREM1 gene. Diagnosis of MOTA syndrome was then established. Conclusions We discovered the first sporadic case of MOTA syndrome according to clinical manifestations and genetic etiology in the Chinese population. We have identified 2 novel stop-gain mutations in FREM1 gene which further expands the spectrum of mutational seen in the MOTA syndrome. Further research should be conducted for better understanding of its mechanism, establishment of an accurate diagnosis, and eventually the exploitation of a more effective and comprehensive therapeutic intervention for MOTA syndrome.

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