scholarly journals Next-Generation Molecular Investigations in Lysosomal Diseases: Clinical Integration of a Comprehensive Targeted Panel

Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 294
Author(s):  
Bénédicte Sudrié-Arnaud ◽  
Sarah Snanoudj ◽  
Ivana Dabaj ◽  
Hélène Dranguet ◽  
Lenaig Abily-Donval ◽  
...  

Diagnosis of lysosomal disorders (LDs) may be hampered by their clinical heterogeneity, phenotypic overlap, and variable age at onset. Conventional biological diagnostic procedures are based on a series of sequential investigations and require multiple sampling. Early diagnosis may allow for timely treatment and prevent clinical complications. In order to improve LDs diagnosis, we developed a capture-based next generation sequencing (NGS) panel allowing the detection of single nucleotide variants (SNVs), small insertions and deletions, and copy number variants (CNVs) in 51 genes related to LDs. The design of the LD panel covered at least coding regions, promoter region, and flanking intronic sequences for 51 genes. The validation of this panel consisted in testing 21 well-characterized samples and evaluating analytical and diagnostic performance metrics. Bioinformatics pipelines have been validated for SNVs, indels and CNVs. The clinical output of this panel was tested in five novel cases. This capture-based NGS panel provides an average coverage depth of 474× which allows the detection of SNVs and CNVs in one comprehensive assay. All the targeted regions were covered above the minimum required depth of 30×. To illustrate the clinical utility, five novel cases have been sequenced using this panel and the identified variants have been confirmed using Sanger sequencing or quantitative multiplex PCR of short fluorescent fragments (QMPSF). The application of NGS as first-line approach to analyze suspected LD cases may speed up the identification of alterations in LD-associated genes. NGS approaches combined with bioinformatics analyses, are a useful and cost-effective tool for identifying the causative variations in LDs.

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2162 ◽  
Author(s):  
Hyunseok P. Kang ◽  
Jared R. Maguire ◽  
Clement S. Chu ◽  
Imran S. Haque ◽  
Henry Lai ◽  
...  

Hereditary breast and ovarian cancer syndrome, caused by a germline pathogenic variant in theBRCA1orBRCA2(BRCA1/2) genes, is characterized by an increased risk for breast, ovarian, pancreatic and other cancers. Identification of those who have aBRCA1/2mutation is important so that they can take advantage of genetic counseling, screening, and potentially life-saving prevention strategies. We describe the design and analytic validation of the Counsyl Inherited Cancer Screen, a next-generation-sequencing-based test to detect pathogenic variation in theBRCA1andBRCA2genes. We demonstrate that the test is capable of detecting single-nucleotide variants (SNVs), short insertions and deletions (indels), and copy-number variants (CNVs, also known as large rearrangements) with zero errors over a 114-sample validation set consisting of samples from cell lines and deidentified patient samples, including 36 samples withBRCA1/2pathogenic germline mutations.


2020 ◽  
Vol 5 (3) ◽  
pp. 467-479 ◽  
Author(s):  
Malinda Butz ◽  
Amber McDonald ◽  
Patrick A Lundquist ◽  
Melanie Meyer ◽  
Sean Harrington ◽  
...  

Abstract Background Deafness and hearing loss are common conditions that can be seen independently or as part of a syndrome and are often mediated by genetic causes. We sought to develop and validate a hereditary hearing loss panel (HHLP) to detect single nucleotide variants (SNVs), insertions and deletions (indels), and copy number variants (CNVs) in 166 genes related to nonsyndromic and syndromic hearing loss. Methods We developed a custom-capture next-generation sequencing (NGS) reagent to detect all coding regions, ±10 flanking bp, for the 166 genes related to nonsyndromic and syndromic hearing loss. Our validation consisted of testing 52 samples to establish accuracy, reproducibility, and analytical sensitivity. In addition to NGS, supplementary methods, including multiplex ligation-dependent probe amplification, long-range PCR, and Sanger sequencing, were used to ensure coverage of regions that had high complexity or homology. Results We observed 100% positive and negative percentage agreement for detection of SNVs (n = 362), small indels (1–22 bp, n = 25), and CNVs (gains, n = 8; losses, n = 17). Finally, we showed that this assay was able to detect variants with a variant allele frequency ≥20% for SNVs and indels and ≥30% to 35% for CNVs. Conclusions We validated an HHLP that detects SNVs, indels, and CNVs in 166 genes related to syndromic and nonsyndromic hearing loss. The results of this assay can be utilized to confirm a diagnosis of hearing loss and related syndromic disorders associated with known causal genes.


2017 ◽  
Author(s):  
Sarah Garcia ◽  
Stephen Williams ◽  
Andrew Wei Xu ◽  
Jill Herschleb ◽  
Patrick Marks ◽  
...  

SummaryLarge genomic structural variants (>50bp) are important contributors to disease, yet they remain one of the most difficult types of variation to accurately ascertain, in part because they tend to cluster in duplicated and repetitive regions, but also because the various signals for these events can be challenging to detect with short reads. Clinically, aCGH and karyotype remain the most commonly used assays for genome-wide structural variant (SV) detection, though there is clear potential benefit to an NGS-based assay that accurately detects both SVs and single nucleotide variants. Linked-Read sequencing is a relatively simple, fast, and cost-effective method that is applicable to both genome and targeted assays. Linked-Reads are generated by performing haplotype-level dilution of long input DNA molecules into >1 million barcoded partitions, generating barcoded short reads within those partitions, and then performing short read sequencing in bulk. We performed 30x Linked-Read genome sequencing on a set of 23 samples with known balanced or unbalanced SVs. Twenty-seven of the 29 known events were detected and another event was called as a candidate. Sequence downsampling was performed on a subset to determine the lowest sequence depth required to detect variations. Copy-number variants can be called with as little as 1-2x sequencing depth (5-10Gb) while balanced events require on the order of 10x coverage for variant calls to be made, although specific signal is clearly present at 1-2x sequencing depth. In addition to detecting a full spectrum of variant types with a single test, Linked-Read sequencing provides base-level resolution of breakpoints, enabling complete resolution of even the most complex chromosomal rearrangements.


2021 ◽  
Vol 12 ◽  
Author(s):  
Komal M. Patel ◽  
Arpan D. Bhatt ◽  
Krati Shah ◽  
Bhargav N. Waghela ◽  
Ramesh J. Pandit ◽  
...  

Muscular Dystrophies (MDs) are a group of inherited diseases and heterogeneous in nature. To date, 40 different genes have been reported for the occurrence and/or progression of MDs. This study was conducted to demonstrate the application of next-generation sequencing (NGS) in developing a time-saving and cost-effective diagnostic method to detect single nucleotide variants (SNVs) and copy number variants (CNVs) in a single test. A total of 123 cases clinically suspected of MD were enrolled in this study. Amplicon panel-based diagnosis was carried out for 102 (DMD/BMD) cases and the results were further screened using multiplex ligation-dependent probe amplification (MLPA). Whilst in the case of LGMD (N = 19) and UMD (N = 2), only NGS panel-based analysis was carried out. We identified the large deletions in 74.50% (76/102) of the cases screened with query DMD or BMD. Further, the large deletion in CAPN3 gene (N = 3) and known SNV mutations (N = 4) were identified in LGMD patients. Together, the total diagnosis rate for this amplicon panel was 70.73% (87/123) which demonstrated the utility of panel-based diagnosis for high throughput, affordable, and time-saving diagnostic strategy. Collectively, present study demonstrates that the panel based NGS sequencing could be superior over to MLPA.


2021 ◽  
Vol 22 (12) ◽  
pp. 6419
Author(s):  
Janine Reurink ◽  
Adrian Dockery ◽  
Dominika Oziębło ◽  
G. Jane Farrar ◽  
Monika Ołdak ◽  
...  

A substantial proportion of subjects with autosomal recessive retinitis pigmentosa (arRP) or Usher syndrome type II (USH2) lacks a genetic diagnosis due to incomplete USH2A screening in the early days of genetic testing. These cases lack eligibility for optimal genetic counseling and future therapy. USH2A defects are the most frequent cause of USH2 and are also causative in individuals with arRP. Therefore, USH2A is an important target for genetic screening. The aim of this study was to assess unscreened or incompletely screened and unexplained USH2 and arRP cases for (likely) pathogenic USH2A variants. Molecular inversion probe (MIP)-based sequencing was performed for the USH2A exons and their flanking regions, as well as published deep-intronic variants. This was done to identify single nucleotide variants (SNVs) and copy number variants (CNVs) in 29 unscreened or partially pre-screened USH2 and 11 partially pre-screened arRP subjects. In 29 out of these 40 cases, two (likely) pathogenic variants were successfully identified. Four of the identified SNVs and one CNV were novel. One previously identified synonymous variant was demonstrated to affect pre-mRNA splicing. In conclusion, genetic diagnoses were obtained for a majority of cases, which confirms that MIP-based sequencing is an effective screening tool for USH2A. Seven unexplained cases were selected for future analysis with whole genome sequencing.


2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Chihiro Hata ◽  
Hirofumi Nakaoka ◽  
Yu Xiang ◽  
Dong Wang ◽  
Anping Yang ◽  
...  

Abstract Multigene panel testing via next-generation sequencing focuses on the detection of small-sized mutations, such as single nucleotide variants and short insertions and deletions (INDELs). However, intermediate-sized INDELs have not been fully explored due to technical difficulties. Here, we performed bioinformatics analyses to identify intermediate-sized INDELs in 54 cancer-related genes from 583 Han Chinese patients with breast cancer. We detected a novel deletion–insertion in a translational variant of PTEN (also known as PTENα) in one patient.


2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e18547-e18547
Author(s):  
Man Hu ◽  
Jinming Yu ◽  
Zihan Zhou ◽  
Peifeng Li ◽  
Xianbin Zhang ◽  
...  

e18547 Background: Even though local and regional controls have been substantially improved in nasopharyngeal carcinoma (NPC) in the contemporary era of intensity-modulated radiotherapy with extensive use of combined chemotherapy, the distant metastasis becomes the major cause of treatment failure and cancer-related death. To date, the genes contributed to metastasis of NPC is still unclear. The aim of this study was to identify the genes which lead to distant metastasis. Methods: A total of forty primary nonkeratinizing NPC patients were diagnosed at Shandong Cancer Hospital in this study. The formaldehyde-fixed paraffin embedded (FFPE) taken from primary sites or metastatic lymph nodes were performed next-generation sequencing (NGS) panel (Shanghai OrigiMed Co., Ltd.) to determine variated genes, such as single nucleotide variants (SNV), copy number variants (CNV) and rearrangement. These patients were followed up until Febr. 8, 2020. The genes related to distant metastasis were identified by logistic regression. Moreover, this study compared the frequency of mutated gene between our data and Catalog of Somatic Mutations in Cancer (COSMIC) database by the Chi-square test or Fisher’s exact test. Results: The study included 31 men and 9 women. The median age of the patients at diagnosis was 47 years (range 15–71 years). With the median follow-up of 10.6 months (range 16.8–72.3 months), 7 patients had distant metastasis and 1 undergone recurrent. Notably, EMSY and MCL1 variants were contributed to NPC distant metastasis (OR = 31, P = 0.049). The top eight SNV of genes in our study were CYLD, KMT2D, BAP1, EP300, TP53, ATM, NFKBIA and SPEN. When compared to COSMIC database, the mutant frequencies of CYLD, EP300 and BAP1 in our study were significantly higher than that of COSMIC database. However, the mutant frequencies of IDH2 and KMT2C were significantly lower than COSMIC database. Conclusions: This is the first study which suggests that EMSY and MCL1 variants were involved in the metastasis of NPC. The study identified 5 genes, which mutation frequency is significantly different from the COSMIC database. The study provided a molecular basis for a comprehensive understanding of, and exploring targeted therapies for nasopharyngeal carcinoma.


Author(s):  
Maheen Nisar

Rapid progress is being made in the development of next-generation sequencing (NGS) technologies, allowing repeated findings of new genes and a more in-depth analysis of genetic polymorphisms behind the pathogenesis of a disease. In a field such as psychiatry, characteristic of vague and highly variable somatic manifestations, these technologies have brought great advances towards diagnosing various psychiatric and mental disorders, identifying high-risk individuals and towards more effective corresponding treatment. Psychiatry has the difficult task of diagnosing and treating mental disorders without being able to invariably and definitively establish the properties of its illness. This calls for diagnostic technologies that go beyond the traditional ways of gene manipulation to more advanced methods mainly focusing on new gene polymorphism discoveries, one of them being NGS. This enables the identification of hundreds of common and rare genetic variations contributing to behavioral and psychological conditions. Clinical NGS has been useful to detect copy number and single nucleotide variants and to identify structural rearrangements that have been challenging for standard bioinformatics algorithms. The main objective of this article is to review the recent applications of NGS in the diagnosis of major psychiatric disorders, and hence gauge the extent of its impact in the field. A comprehensive PubMed search was conducted and papers published from 2013-2018 were included, using the keywords, “schizophrenia” or “bipolar disorder” or “depressive disorder” or “attention deficit disorder” or “autism spectrum disorder” and “next-generation sequencing”


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