scholarly journals Sorting Rare ALS Genetic Variants by Targeted Re-Sequencing Panel in Italian Patients: OPTN, VCP, and SQSTM1 Variants Account for 3% of Rare Genetic Forms

2020 ◽  
Vol 9 (2) ◽  
pp. 412 ◽  
Author(s):  
Viviana Pensato ◽  
Stefania Magri ◽  
Eleonora Dalla Bella ◽  
Pierpaola Tannorella ◽  
Enrica Bersano ◽  
...  

Amyotrophic lateral sclerosis (ALS) is an adult-onset progressive neurodegenerative disease due to motor neuron loss variably associated with frontotemporal dementia (FTD). Next generation sequencing technology revealed an increasing number of rare and novel genetic variants and interpretation of their pathogenicity represents a major challange in the diagnosis of ALS. We selected 213 consecutive patients with sporadic or familial (16%) ALS, tested negative for SOD1, FUS, TARDBP, and C9orf72 mutations. To reveal rare forms of genetic ALS, we performed a comprehensive multi-gene panel screening including 46 genes associated with ALS, hereditary motor neuronopathies, spastic paraplegia, and FTD. Our study allowed the identification of pathogenic or likely pathogenic variants in 4.2% of patients. The genes with the highest percentage of pathogenic variants were OPTN (1%), VCP (1%) SQSTM1(1%), SETX (0.4%), FIG4 (0.4%), and GARS1 (0.4%) genes. We also found 49 novel or rare gene variants of unknown significance in 30 patients (14%), 44 unlikely pathogenic variants (39%), and 48 variants in ALS susceptibility genes. The results of our study suggest the screening of OPTN, VCP, and SQSTM1 genes in routine diagnostic investigations for both sporadic and familial cases, and confirm the importance of diagnosis and couselling for patients and their relative family members.

Diagnostics ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1378
Author(s):  
Vincenzo Castiglione ◽  
Martina Modena ◽  
Alberto Aimo ◽  
Enrica Chiti ◽  
Nicoletta Botto ◽  
...  

Molecular autopsy is the process of investigating sudden death through genetic analysis. It is particularly useful in cases where traditional autopsy is negative or only shows non-diagnostic features, i.e., in sudden unexplained deaths (SUDs), which are often due to an underlying inherited arrhythmogenic cardiac disease. The final goal of molecular autopsy in SUD cases is to aid medico-legal inquiries and to guide cascade genetic screening of the victim’s relatives. Early attempts of molecular autopsy relied on Sanger sequencing, which, despite being accurate and easy to use, has a low throughput and can only be employed to analyse a small panel of genes. Conversely, the recent adoption of next-generation sequencing (NGS) technologies has allowed exome/genome wide examination, providing an increase in detection of pathogenic variants and the discovery of newer genotype-phenotype associations. NGS has nonetheless brought new challenges to molecular autopsy, especially regarding the clinical interpretation of the large number of variants of unknown significance detected in each individual.


2021 ◽  
Author(s):  
Amein Kadhem AlAli ◽  
Abdulrahman Al-Enazi ◽  
Ahmed Ammar ◽  
Mahmoud Hajj ◽  
Cyril Cyrus ◽  
...  

Abstract Background Epilepsy, a serious chronic neurological condition effecting up to 100 million people globally, has clear genetic underpinnings including common and rare variants. In Saudi Arabia the prevalence of epilepsy is high and caused mainly by perinatal and genetic factors. No whole-exome sequencing (WES) studies have been performed to date in Saudi Arabian Epilepsy cohorts. This offers a unique opportunity for the discovery of rare genetic variants impacting this disease as there is a high rate of consanguinity amongst large tribal pedigrees. Results We performed WES on 144 individuals diagnosed with epilepsy, to interrogate known Epilepsy related genes for known and functional novel variants. We also used an American College of Medical Genetics (ACMG) guideline based variant prioritization approach in an attempt to discover putative causative variants. We identified a 32 potentially causative pathogenic variants across 30 different genes in 44/144 (30%) of these Saudi Epilepsy individuals. We also identified 232 variants of unknown significance (VUS) across 101 different genes in 133/144 (92%) subjects. Strong enrichment of variants of likely pathogenicity were observed in previously described epilepsy-associated loci, and a number of putative pathogenic variants in novel loci are also observed. Conclusion Several putative pathogenic variants known to be epilepsy-related loci were identified for the first time in our population, in addition to several potential new loci have been identified which may be prioritized for further investigation.


2019 ◽  
Vol 2 ◽  
pp. 251581631988163 ◽  
Author(s):  
Neven Maksemous ◽  
Robert A Smith ◽  
Heidi G Sutherland ◽  
Bridget H Maher ◽  
Omar Ibrahim ◽  
...  

Objective: Hemiplegic migraine in both familial (FHM) and sporadic (SHM) forms is a rare subtype of migraine with aura that can be traced to mutations in the CACNA1A, ATP1A2 and SCN1A genes. It is characterised by severe attacks of typical migraine accompanied by hemiparesis, as well as episodes of complex aura that vary significantly between individuals. Methods: Using a targeted next generation sequencing (NGS) multigene panel, we have sequenced the genomic DNA of 172 suspected hemiplegic migraine cases, in whom no mutation had previously been found by Sanger sequencing (SS) of a limited number of exons with high mutation frequency in FHM genes. Results: Genetic screening identified 29 variants, 10 of which were novel, in 35 cases in the three FHM genes ( CACNA1A, ATP1A2 and SCN1A). Interestingly, in this suspected HM cohort, the ATP1A2 gene harboured the highest number of variants with 24/35 cases (68.6%), while CACNA1A ranked the second gene, with 5 variants identified in 7/35 cases (20%). All detected variants were confirmed by SS and were absent in 100 non-migraine healthy control individuals. Assessment of variants with the American College of Medical Genetics and Genomics guidelines classified 8 variants as pathogenic, 3 as likely pathogenic and 18 as variants of unknown significance. Targeted NGS gene panel increased the diagnostic yield by fourfold over iterative SS in our diagnostics facility. Conclusion: We have identified 29 potentially causative variants in an Australian and New Zealand cohort of suspected HM cases and found that the ATP1A2 gene was the most commonly mutated gene. Our results suggest that screening using NGS multigene panels to investigate ATP1A2 alongside CACNA1A and SCN1A is a clinically useful and efficient method.


Cardiology ◽  
2020 ◽  
Vol 145 (11) ◽  
pp. 746-756
Author(s):  
Tatiana Vershinina ◽  
Yulia Fomicheva ◽  
Alexey Muravyev ◽  
John Jorholt ◽  
Alexandra Kozyreva ◽  
...  

<b><i>Introduction:</i></b> Left ventricular non-compaction (LVNC) represents a genetically heterogeneous cardiomyopathy which occurs in both children and adults. Its genetic spectrum overlaps with other types of cardiomyopathy. However, LVNC phenotypes in different age groups can have distinct genetic aetiologies. The aim of the study was to decipher the genetic spectrum of LVNC presented in childhood. <b><i>Patient Group and Methods:</i></b> Twenty patients under the age of 18 years diagnosed with LVNC were enrolled in the study. Target sequencing and whole-exome sequencing were performed using a panel of 108 cardiomyopathy-associated genes. Pathogenic, likely pathogenic, and variants of unknown significance found in genes highly expressed in cardiomyocytes were considered as variants of interest for further analysis. <b><i>Results:</i></b> The median age at presentation was 8.0 (0.1–17) years, with 6 patients presenting before 1 year of age. Twelve (60%) patients demonstrated reduced ejection fraction. Right ventricular (RV) dilation was registered in 6 (30%), often in combination with reduced RV contractility (25%). Almost half (45%) of the patients demonstrated biventricular involvement already at disease presentation. For pathogenic and likely pathogenic variants, the positive genotyping rate was 45%, and these variants were found mainly in non-contractile structural sarcomeric genes (<i>ACTN2</i>, <i>MYPN</i>, and <i>TTN</i>) or in metabolic and signal transduction genes (<i>BRAF</i> and <i>TAZ</i>). Likely pathogenic <i>TAZ</i> variants were detected in all 5 patients suspected of having Barth syndrome. No pathogenic or likely pathogenic variants were found in genes encoding for sarcomeric contractile proteins, but variants of unknown significance were detected in 3 out of 20 patients (<i>MYH6</i>, <i>MYH7</i>, and <i>MYLK2</i>). In 4 patients, variants of unknown significance in ion-channel genes were detected. <b><i>Conclusion:</i></b> We detected a low burden of contractile sarcomeric variants in LVNC patients presenting below the age of 18 years, with the major number of variants residing in non-contractile structural sarcomeric genes. The identification of the variants in ion-channel and related genes not previously associated with LVNC in paediatric patients requires further examination of their functional role.


2020 ◽  
Vol 57 (11) ◽  
pp. 752-759 ◽  
Author(s):  
Alexandre Buffet ◽  
Bruna Calsina ◽  
Shahida Flores ◽  
Sophie Giraud ◽  
Marion Lenglet ◽  
...  

BackgroundsThe incidence of germline mutations in the newly discovered cryptic exon (E1’) of VHL gene in patients with von Hippel-Lindau (VHL) disease and in patients with paraganglioma or pheochromocytoma (PPGL) is not currently known.MethodsWe studied a large international multicentre cohort of 1167 patients with a previous negative genetic testing. Germline DNA from 75 patients with a single tumour of the VHL spectrum (‘Single VHL tumour’ cohort), 70 patients with multiple tumours of the VHL spectrum (‘Multiple VHL tumours’ cohort), 76 patients with a VHL disease as described in the literature (‘VHL-like’ cohort) and 946 patients with a PPGL were screened for E1’ genetic variants.ResultsSix different genetic variants in E1' were detected in 12 patients. Two were classified as pathogenic, 3 as variants of unknown significance and 1 as benign. The rs139622356 was found in seven unrelated patients but described in only 16 patients out of the 31 390 of the Genome Aggregation Database (p<0.0001) suggesting that this variant might be either a recurrent mutation or a modifier mutation conferring a risk for the development of tumours and cancers of the VHL spectrum.ConclusionsVHL E1’ cryptic exon mutations contribute to 1.32% (1/76) of ‘VHL-like’ cohort and to 0.11% (1/946) of PPGL cohort and should be screened in patients with clinical suspicion of VHL, and added to panels for Next Generation Sequencing (NGS) diagnostic testing of hereditary PPGL. Our data highlight the importance of studying variants identified in deep intronic sequences, which would have been missed by examining only coding sequences of genes/exomes. These variants will likely be more frequently detected and studied with the upcoming implementation of whole-genome sequencing into clinical practice.


2015 ◽  
Vol 22 (4) ◽  
pp. T123-T133 ◽  
Author(s):  
Arthur S Tischler ◽  
Ronald R deKrijger

Pathologists using their routine diagnostic tools can contribute both to the care of patients with pheochromocytoma/paraganglioma and to understanding the pathobiology of the tumors. They can document details of tissue organization and cytology that are accessible only by microscopy and can characterize admixtures of cell types that are morphologically distinct or show differential expression of immunohistochemical markers. Current roles and challenges for pathologists include differential diagnosis, identifying clues to the presence of hereditary disease, and effective communication of pathology information for clinical and research purposes. Future roles will increasingly involve risk stratification, identification of actionable targets for personalized therapies, and aiding the interpretation of molecular tests by helping characterize genetic variants of unknown significance. It remains to be determined to what extent the need for pathology input will be overshadowed by the availability of genetic testing and other molecular analyses at ever-decreasing cost, together with very effective clinical paradigms for risk stratification and patient care.


Author(s):  
Débora Cabral de Carvalho Corrêa ◽  
Francine Tesser-Gamba ◽  
Nasjla da Silva ◽  
Andrea Capellano ◽  
Maria Teresa Alves ◽  
...  

Background Congenital GBM (cGBM), presenting prenatally or within the first months of life, is among the rarest type of congenital brain tumor, with approximately 120 cases reported. Due to its infrequent occurrence, few studies have focused on the molecular and genetic aspects of this tumor, and the mutational events involved in the pathogenesis and progression of cGBM still remains poorly understood. This study aimed to investigate molecular alterations, with a potential prognostic marker and therapeutic target in cGBM using the next-generation sequencing (NGS) strategy. Methods We selected seven tumor samples from patients diagnosed with cGBM and treated at Pediatric Oncology Institute-GRAACC/UNIFESP. NGS was performed to identify somatic genetic variants in tumor samples using the Oncomine Childhood Cancer Research Assay panel, from ThermoFisher Scientific, designed specifically for pediatric neoplasms. Results Of all seven patients analyzed, three patients exhibited tumors with genetic variants, which include two pathogenic variants in NF1 and SUZ12 genes that have not been reported in cGBM yet, an increase in the number of copies of ALK gene, and two gene fusions, PPP1CB-ALK and TPM3-NTRK1. Also, none of the cases showed variants in H3F3A, TP53 and ATRX genes, alterations which are frequently seen in pediatric and adolescent GBM. Conclusions Our results suggest that cGBM may comprise a unique tumor entity and alterations in ALK and NTRK genes provide a potential target for therapy. Therefore, identification of genetic variants in cGBM is highly relevant in order to define prognosis and therapeutic strategies.


Author(s):  
Fang Zhao ◽  
David S. Bosler ◽  
James R. Cook

Context.— Next-generation sequencing studies are increasingly used in the evaluation of suspected chronic myeloid neoplasms (CMNs), but there is wide variability among laboratories in the genes analyzed for this purpose. Recently, the Association for Molecular Pathology CMN working group recommended a core 34-gene set as a minimum target list for evaluation of CMNs. This list was recommended based on literature review, and its diagnostic yield in clinical practice is unknown. Objective.— To determine the diagnostic yield of the core 34 genes and assess the potential impact of including selected additional genes. Design.— We retrospectively reviewed 185 patients with known or suspected CMNs tested using a 62-gene next-generation sequencing panel that included all 34 core genes. Results.— The Association for Molecular Pathology's core 34 genes had a diagnostic yield of 158 of 185 (85.4%) to detect at least 1 variant with strong/potential clinical significance and 107 of 185 (57.8%) to detect at least 2 such variants. The 62-gene panel had a diagnostic yield of 160 of 185 (86.5%) and 112 of 185 (60.5%), respectively. Variants of unknown significance were identified in 49 of 185 (26.5%) using the core 34 genes versus 76 of 185 (41.1%) using the 62-gene panel. Conclusions.— This study demonstrates that the Association for Molecular Pathology–recommended core 34-gene set has a high diagnostic yield in CMNs. Inclusion of selected additional genes slightly increases the rate of abnormal results, while also increasing the detection of variants of unknown significance. We recommend inclusion of CUX1, DDX41, ETNK1, RIT1, and SUZ12 in addition to the Association for Molecular Pathology's 34-gene core set for routine evaluation of CMNs.


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