scholarly journals Application of a custom NGS Gene Panel revealed a high diagnostic utility for molecular testing of hereditary ataxias.

2021 ◽  
Author(s):  
Wiktoria Radziwonik ◽  
Ewelina Elert-Dobkowska ◽  
Aleksandra Klimkowicz-Mrowiec ◽  
Karolina Ziora-Jakutowicz ◽  
Iwona Stepniak ◽  
...  
Keyword(s):  
Molecular Diagnosis ◽  
Molecular Testing ◽  
Diagnostic Efficiency ◽  
Integrative Genomics ◽  
Hereditary Ataxias ◽  
Pathogenic Variants ◽  
Targeted Ngs ◽  
Hsp Genes ◽  
Next Generation Sequencing Ngs ◽  
Rare Group

Abstract Background Hereditary ataxias (HA) are a rare group of heterogeneous disorders. Here, we present results of molecular testing a group of ataxia patients using custom-designed Next Generation Sequencing (NGS) panel. Due to genetic and clinical overlapping of hereditary ataxias and spastic paraplegias (HSP), designed panel encompassing together HA and HSP genes. Methods The NGS libraries comprising coding sequence for 152 genes were performed using KAPA HyperPlus and HyperCap Target Enrichment Kit and sequenced on the MiSeq instrument. Obtained results were analyzed using BaseSpace Variant Interpreter and Integrative Genomics Viewer. All pathogenic and likely pathogenic variants were confirmed using the Sanger sequencing. Results A total of 29 patients with hereditary ataxias were enrolled to the NGS testing, and 16 patients had a confirmed molecular diagnosis with diagnostic efficiency of 55.2%. Pathogenic or likely pathogenic mutations were identified in 10 different genes: POLG (PEOA1, n=3; SCAE, n=2), CACNA1A (EA2, n=2), SACS (ARSACS, n=2), SLC33A1 (SPG42, n=2), STUB1 (SCA48, n=1), SPTBN2 (SCA5, n=1), TGM6 (SCA35, n=1), SETX (AOA2, n=1), ANO10 (SCAR10, n=1), SPAST (SPG4, n=1). Conclusions We demonstrated that approach based on targeted NGS panel can be highly effective and useful tool in the molecular diagnosis of ataxia patients. Furthermore, we highlight that sequencing panel targeted to ataxias together with HSP genes increase the diagnostic success.

scholarly journals Next Generation Sequencing Identifies Five Novel Mutations in Lebanese Patients with Bardet–Biedl and Usher Syndromes

Genes ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1047 ◽  
Author(s):  
Lama Jaffal ◽  
Wissam H Joumaa ◽  
Alexandre Assi ◽  
Charles Helou ◽  
George Cherfan ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Usher Syndrome ◽  
Bioinformatic Analysis ◽  
Next Generation ◽  
Novel Mutations ◽  
Pathogenic Variants ◽  
Whole Exome ◽  
Targeted Ngs ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing

Aim: To identify disease-causing mutations in four Lebanese families: three families with Bardet–Biedl and one family with Usher syndrome (BBS and USH respectively), using next generation sequencing (NGS). Methods: We applied targeted NGS in two families and whole exome sequencing (WES) in two other families. Pathogenicity of candidate mutations was evaluated according to frequency, conservation, in silico prediction tools, segregation with disease, and compatibility with inheritance pattern. The presence of pathogenic variants was confirmed via Sanger sequencing followed by segregation analysis. Results: Most likely disease-causing mutations were identified in all included patients. In BBS patients, we found (M1): c.2258A > T, p. (Glu753Val) in BBS9, (M2): c.68T > C; p. (Leu23Pro) in ARL6, (M3): c.265_266delTT; p. (Leu89Valfs*11) and (M4): c.880T > G; p. (Tyr294Asp) in BBS12. A previously known variant (M5): c.551A > G; p. (Asp184Ser) was also detected in BBS5. In the USH patient, we found (M6): c.188A > C, p. (Tyr63Ser) in CLRN1. M2, M3, M4, and M6 were novel. All of the candidate mutations were shown to be likely disease-causing through our bioinformatic analysis. They also segregated with the corresponding phenotype in available family members. Conclusion: This study expanded the mutational spectrum and showed the genetic diversity of BBS and USH. It also spotlighted the efficiency of NGS techniques in revealing mutations underlying clinically and genetically heterogeneous disorders.

scholarly journals Progressive Myoclonus Epilepsies

2021 ◽  
Vol 7 (6) ◽  
pp. e641
Author(s):  
Laura Canafoglia ◽  
Silvana Franceschetti ◽  
Antonio Gambardella ◽  
Pasquale Striano ◽  
Anna Teresa Giallonardo ◽  
...  
Keyword(s):  
Late Onset ◽  
Diagnostic Yield ◽  
Homozygosity Mapping ◽  
Genetic Origin ◽  
Pathogenic Variants ◽  
Whole Exome ◽  
Progressive Ataxia ◽  
Targeted Ngs ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing

Background and ObjectivesTo assess the current diagnostic yield of genetic testing for the progressive myoclonus epilepsies (PMEs) of an Italian series described in 2014 where Unverricht-Lundborg and Lafora diseases accounted for ∼50% of the cohort.MethodsOf 47/165 unrelated patients with PME of indeterminate genetic origin, 38 underwent new molecular evaluations. Various next-generation sequencing (NGS) techniques were applied including gene panel analysis (n = 7) and/or whole-exome sequencing (WES) (WES singleton n = 29, WES trio n = 7, and WES sibling n = 4). In 1 family, homozygosity mapping was followed by targeted NGS. Clinically, the patients were grouped in 4 phenotypic categories: “Unverricht-Lundborg disease-like PME,” “late-onset PME,” “PME plus developmental delay,” and “PME plus dementia.”ResultsSixteen of 38 (42%) unrelated patients reached a positive diagnosis, increasing the overall proportion of solved families in the total series from 72% to 82%. Likely pathogenic variants were identified in NEU1 (2 families), CERS1 (1 family), and in 13 nonfamilial patients in KCNC1 (3), DHDDS (3), SACS, CACNA2D2, STUB1, AFG3L2, CLN6, NAXE, and CHD2. Across the different phenotypic categories, the diagnostic rate was similar, and the same gene could be found in different phenotypic categories.DiscussionThe application of NGS technology to unsolved patients with PME has revealed a collection of very rare genetic causes. Pathogenic variants were detected in both established PME genes and in genes not previously associated with PME, but with progressive ataxia or with developmental encephalopathies. With a diagnostic yield >80%, PME is one of the best genetically defined epilepsy syndromes.

scholarly journals Expanded Analysis of Secondary Germline Findings From Matched Tumor/Normal Sequencing Identifies Additional Clinically Significant Mutations

2019 ◽  
pp. 1-11 ◽  
Author(s):  
Ecaterina Ileana Dumbrava ◽  
Lauren Brusco ◽  
Molly S. Daniels ◽  
Chetna Wathoo ◽  
Kenna R. Shaw ◽  
...  
Keyword(s):  
Clinical Utility ◽  
Molecular Testing ◽  
Pathogenic Variants ◽  
Cancer Related Gene ◽  
Predisposition Genes ◽  
Potential Clinical Utility ◽  
Genetics And Genomics ◽  
Clinically Significant ◽  
Next Generation Sequencing Ngs ◽  
Secondary Results

Purpose Next-generation sequencing (NGS) for tumor molecular profiling can reveal secondary germline likely pathogenic and pathogenic variants (LPV/PV). The American College of Medical Genetics and Genomics (ACMG) recommends return of secondary results for a subset of 59 genes, but other genes with evidence of clinical utility are emerging. We previously reported that 4.3% of patients who underwent NGS of a targeted panel of 201 genes had LPV/PV on the basis of the ACMG list. We report the frequency of additional germline cancer-related gene variants and discuss their clinical utility. Patients and Methods Matched tumor and germline DNA NGS of a targeted panel of 201 genes was performed in a research laboratory on samples from 1,000 patients with advanced or metastatic solid tumors enrolled in a molecular testing protocol ( ClinicalTrials.gov identifier: NCT01772771). The frequency of germline LPV/PV in 54 cancer-related genes, beyond the genes in ACMG list, were analyzed. Results Among 1,000 patients who underwent tumor/normal DNA sequencing, 46 (4.6%) were found to have a germline LPV/PV in the following genes: AR (n = 5), ATM (n = 4), BAP1 (n = 1), CDH1 (n = 1), CDKN2A (n = 1), CHEK1 (n = 2), CHEK2 (n = 10), EGFR (n = 1), ERCC3 (n = 4), ERCC5 (n = 1), HNF1B (n = 1), HRAS (n = 1), MITF (n = 4), MLL3 (n = 1), NF1 (n = 3), PKHD1 (n = 4), PTCH1 (n = 1), and SMARCA4 (n = 1). Thus, 8.7% of patients had an LPV/PV, with two patients having two concomitant germline LPV/PV. Five mutations in high-penetrance hereditary cancer predisposition genes were selected to be returned to patients or their representatives: BAP1, CDH1, CDKN2A, EGFR, and SMARCA4. Conclusion Broader genomic testing is likely to identify additional secondary pathogenic germline alterations, some with potential clinical utility for return to patients and their relatives. The recommended genes for which germline results should be returned are continually changing, which warrants continued study.

scholarly journals Improving the Management of Patients with Hearing Loss by the Implementation of an NGS Panel in Clinical Practice

Genes ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1467
Author(s):  
Gema García-García ◽  
Alba Berzal-Serrano ◽  
Piedad García-Díaz ◽  
Rebeca Villanova-Aparisi ◽  
Sara Juárez-Rodríguez ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Autosomal Recessive ◽  
Targeted Next Generation Sequencing ◽  
Pathogenic Variants ◽  
Targeted Ngs ◽  
Syndromic Hearing Loss ◽  
Genetics And Genomics ◽  
Custom Panel ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing

A cohort of 128 patients from 118 families diagnosed with non-syndromic or syndromic hearing loss (HL) underwent an exhaustive clinical evaluation. Molecular analysis was performed using targeted next-generation sequencing (NGS) with a custom panel that included 59 genes associated with non-syndromic HL or syndromic HL. Variants were prioritized according to the minimum allele frequency and classified according to the American College of Medical Genetics and Genomics guidelines. Variant(s) responsible for the disease were detected in a 40% of families including autosomal recessive (AR), autosomal dominant (AD) and X-linked patterns of inheritance. We identified pathogenic or likely pathogenic variants in 26 different genes, 15 with AR inheritance pattern, 9 with AD and 2 that are X-linked. Fourteen of the found variants are novel. This study highlights the clinical utility of targeted NGS for sensorineural hearing loss. The optimal panel for HL must be designed according to the spectrum of the most represented genes in a given population and the laboratory capabilities considering the pressure on healthcare.

scholarly journals Diagnostic difficulties and possibilities of NF1-like syndromes in childhood

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Eva Pinti ◽  
Krisztina Nemeth ◽  
Krisztina Staub ◽  
Anna Lengyel ◽  
Gyorgy Fekete ◽  
...  
Keyword(s):  
Diagnostic Criteria ◽  
Neurofibromatosis Type ◽  
Early Years ◽  
Diagnostic Efficiency ◽  
Clinical Criteria ◽  
Pathogenic Variants ◽  
Clinical Diagnostic ◽  
Long Time ◽  
Diagnostic Difficulties ◽  
Clinical Diagnostic Criteria

Abstract Background Neurofibromatosis type 1 (NF1), which is caused by heterozygous inactivating pathogenic variants in the NF1, has poor phenotypic expressivity in the early years of life and there are numerous conditions, including many other tumor predisposition syndromes, that can mimic its appearance. These are collectively termed NF1-like syndromes and are also connected by their genetic background. Therefore, the NF1’s clinical diagnostic efficiency in childhood could be difficult and commonly should be completed with genetic testing. Methods To estimate the number of syndromes/conditions that could mimic NF1, we compiled them through an extensive search of the scientific literature. To test the utility of NF1’s National Institutes of Health (NIH) clinical diagnostic criteria, which have been in use for a long time, we analyzed the data of a 40-member pediatric cohort with symptoms of the NF1-like syndromes’ overlapping phenotype and performed NF1 genetic test, and established the average age when diagnostic suspicion arises. To facilitate timely identification, we compiled strongly suggestive phenotypic features and anamnestic data. Results In our cohort the utility of NF1’s clinical diagnostic criteria were very limited (sensitivity: 80%, specificity: 30%). Only 53% of children with clinically diagnosed NF1 had a detectable NF1 pathogenic variation, whereas 40% of patients without fulfilled clinical criteria tested positive. The average age at first genetic counseling was 9 years, and 40% of children were referred after at least one tumor had already been diagnosed. These results highlight the need to improve NF1-like syndromes’ diagnostic efficiency in childhood. We collected the most extensive spectrum of NF1-like syndromes to help the physicians in differential diagnosis. We recommend the detailed, non-invasive clinical evaluation of patients before referring them to a clinical geneticist. Conclusions Early diagnosis of NF1-like syndromes can help to prevent severe complications by appropriate monitoring and management. We propose a potential screening, diagnostic and management strategy based on our findings and recent scientific knowledge.

What Every Neuropathologist Needs to Know: Practical Aspects and Pitfalls in Molecular Diagnosis of Brain Tumors

2021 ◽  
Author(s):  
J Stephen Nix ◽  
Cristiane M Ida
Keyword(s):  
Brain Tumors ◽  
Molecular Diagnosis ◽  
Genetic Alterations ◽  
Genetic Alteration ◽  
Molecular Testing ◽  
Test Results ◽  
Molecular Test ◽  
Molecular Tests ◽  
Clinically Significant ◽  
Selection Of

Abstract Molecular testing has become part of the routine diagnostic workup of brain tumors after the implementation of integrated histomolecular diagnoses in the 2016 WHO classification update. It is important for every neuropathologist to be aware of practical preanalytical, analytical, and postanalytical factors that impact the performance and interpretation of molecular tests. Prior to testing, optimizing tumor purity and tumor amount increases the ability of the molecular test to detect the genetic alteration of interest. Recognizing basic molecular testing platform analytical characteristics allows selection of the optimal platform for each clinicopathological scenario. Finally, postanalytical considerations to properly interpret molecular test results include understanding the clinical significance of the detected genetic alteration, recognizing that detected clinically significant genetic alterations are occasionally germline constitutional rather than somatic tumor-specific, and being cognizant that recommended and commonly used genetic nomenclature may differ. Potential pitfalls in brain tumor molecular diagnosis are also discussed.

scholarly journals Rubinstein-Taybi Syndrome: A Model of Epigenetic Disorder

Genes ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 968
Author(s):  
Julien Van Gils ◽  
Frederique Magdinier ◽  
Patricia Fergelot ◽  
Didier Lacombe
Keyword(s):  
Chromatin Remodeling ◽  
Developmental Disorder ◽  
Facial Dysmorphism ◽  
Diagnostic Efficiency ◽  
Mendelian Disorders ◽  
Pathogenic Variants ◽  
Epigenetic Machinery ◽  
Lysine Acetyltransferase ◽  
Definition Of ◽  
Crebbp Gene

The Rubinstein-Taybi syndrome (RSTS) is a rare congenital developmental disorder characterized by a typical facial dysmorphism, distal limb abnormalities, intellectual disability, and many additional phenotypical features. It occurs at between 1/100,000 and 1/125,000 births. Two genes are currently known to cause RSTS, CREBBP and EP300, mutated in around 55% and 8% of clinically diagnosed cases, respectively. To date, 500 pathogenic variants have been reported for the CREBBP gene and 118 for EP300. These two genes encode paralogs acting as lysine acetyltransferase involved in transcriptional regulation and chromatin remodeling with a key role in neuronal plasticity and cognition. Because of the clinical heterogeneity of this syndrome ranging from the typical clinical diagnosis to features overlapping with other Mendelian disorders of the epigenetic machinery, phenotype/genotype correlations remain difficult to establish. In this context, the deciphering of the patho-physiological process underlying these diseases and the definition of a specific episignature will likely improve the diagnostic efficiency but also open novel therapeutic perspectives. This review summarizes the current clinical and molecular knowledge and highlights the epigenetic regulation of RSTS as a model of chromatinopathy.

scholarly journals BTK, NUTM2A, and PRPF19 Are Novel KMT2A Partner Genes in Childhood Acute Leukemia

Biomedicines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 924
Author(s):  
Elena Zerkalenkova ◽  
Svetlana Lebedeva ◽  
Aleksandra Borkovskaia ◽  
Olga Soldatkina ◽  
Olga Plekhanova ◽  
...  
Keyword(s):  
Acute Leukemia ◽  
Residual Disease ◽  
Chromosomal Rearrangements ◽  
Strong Impact ◽  
Acute Leukemias ◽  
Dna And Rna ◽  
Targeted Ngs ◽  
Childhood Acute Leukemia ◽  
Next Generation Sequencing Ngs ◽  
The Given

Chromosomal rearrangements of the human KMT2A/MLL gene are associated with acute leukemias, especially in infants. KMT2A is rearranged with a big variety of partner genes and in multiple breakpoint locations. Detection of all types of KMT2A rearrangements is an essential part of acute leukemia initial diagnostics and follow-up, as it has a strong impact on the patients’ outcome. Due to their high heterogeneity, KMT2A rearrangements are most effectively uncovered by next-generation sequencing (NGS), which, however, requires a thorough prescreening by cytogenetics. Here, we aimed to characterize uncommon KMT2A rearrangements in childhood acute leukemia by conventional karyotyping, FISH, and targeted NGS on both DNA and RNA level with subsequent validation. As a result of this comprehensive approach, three novel KMT2A rearrangements were discovered: ins(X;11)(q26;q13q25)/KMT2A-BTK, t(10;11)(q22;q23.3)/KMT2A-NUTM2A, and inv(11)(q12.2q23.3)/KMT2A-PRPF19. These novel KMT2A-chimeric genes expand our knowledge of the mechanisms of KMT2A-associated leukemogenesis and allow tracing the dynamics of minimal residual disease in the given patients.

scholarly journals One in seven pathogenic variants can be challenging to detect by NGS: an analysis of 450,000 patients with implications for clinical sensitivity and genetic test implementation

2021 ◽  
Author(s):  
Stephen E. Lincoln ◽  
Tina Hambuch ◽  
Justin M. Zook ◽  
Sara L. Bristow ◽  
Kathryn Hatchell ◽  
...  
Keyword(s):  
Diagnostic Yield ◽  
Copy Number Variants ◽  
Low Complexity ◽  
Clinical Genetic ◽  
Clinical Sensitivity ◽  
Pathogenic Variants ◽  
Wide Range ◽  
Large Indels ◽  
Next Generation Sequencing Ngs ◽  
The Impact

Abstract Purpose To evaluate the impact of technically challenging variants on the implementation, validation, and diagnostic yield of commonly used clinical genetic tests. Such variants include large indels, small copy-number variants (CNVs), complex alterations, and variants in low-complexity or segmentally duplicated regions. Methods An interlaboratory pilot study used synthetic specimens to assess detection of challenging variant types by various next-generation sequencing (NGS)–based workflows. One well-performing workflow was further validated and used in clinician-ordered testing of more than 450,000 patients. Results In the interlaboratory study, only 2 of 13 challenging variants were detected by all 10 workflows, and just 3 workflows detected all 13. Limitations were also observed among 11 less-challenging indels. In clinical testing, 21.6% of patients carried one or more pathogenic variants, of which 13.8% (17,561) were classified as technically challenging. These variants were of diverse types, affecting 556 of 1,217 genes across hereditary cancer, cardiovascular, neurological, pediatric, reproductive carrier screening, and other indicated tests. Conclusion The analytic and clinical sensitivity of NGS workflows can vary considerably, particularly for prevalent, technically challenging variants. This can have important implications for the design and validation of tests (by laboratories) and the selection of tests (by clinicians) for a wide range of clinical indications.

scholarly journals One4Two®: An Integrated Molecular Approach to Optimize Infertile Couples’ Journey

Genes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 60
Author(s):  
Valeria D’Argenio ◽  
Federica Cariati ◽  
Rossella Tomaiuolo
Keyword(s):  
Disease Genes ◽  
Diagnostic Efficacy ◽  
Whole Process ◽  
Pathogenic Variants ◽  
Limiting Step ◽  
Number Of Genes ◽  
Infertile Couples ◽  
Next Generation Sequencing Ngs ◽  
And Diffusion ◽  
Generation Sequencing

The current diagnostic path of infertile couples is long lasting and often ineffective. Genetic tests, in particular, appear as a limiting step due to their jeopardized use on one side, and to the limited number of genes evaluated on the other. In this context, the development and diffusion, also in routine diagnostic settings, of next generation sequencing (NGS)-based methods for the analyses of several genes in multiple subjects at a time is improving the diagnostic sensitivity of molecular analyses. Thus, we developed One4Two®, a custom NGS panel to optimize the diagnostic journey of infertile couples. The panel validation was carried out in three steps analyzing a total of 83 subjects. Interestingly, all the previously identified variants were confirmed, assessing the analytic sensitivity of the method. Moreover, additional pathogenic variants have been identified underlying the diagnostic efficacy of the proposed method. One4Two® allows the simultaneous analysis of infertility-related genes, disease-genes of common inherited diseases, and of polymorphisms related to therapy outcome. Thus, One4Two® is able to improve the diagnostic journey of infertile couples by simplifying the whole process not only for patients, but also for laboratories and reproduction specialists moving toward an even more personalized medicine.

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