scholarly journals The variability of SMCHD1 gene in FSHD patients: evidence of new mutations

2019 ◽  
Vol 28 (23) ◽  
pp. 3912-3920 ◽  
Author(s):  
Claudia Strafella ◽  
Valerio Caputo ◽  
Rosaria Maria Galota ◽  
Giulia Campoli ◽  
Cristina Bax ◽  
...  
Keyword(s):  
Fragment Size ◽  
Facioscapulohumeral Muscular Dystrophy ◽  
Clinical Severity ◽  
Pathogenic Variants ◽  
Uncertain Significance ◽  
Next Generation Sequencing Ngs ◽  
Structural Maintenance Of Chromosomes ◽  
Generation Sequencing ◽  
Hinge Domain ◽  
New Mutations

Abstract In this study, we investigated the sequence of (Structural Maintenance of Chromosomes flexible Hinge Domain containing 1) SMCHD1 gene in a cohort of clinically defined FSHD (facioscapulohumeral muscular dystrophy) patients in order to assess the distribution of SMCHD1 variants, considering the D4Z4 fragment size in terms of repeated units (RUs; short fragment: 1–7 RU, borderline: 8-10RU and normal fragment: >11RU). The analysis of SMCHD1 revealed the presence of 82 variants scattered throughout the introns, exons and 3’untranslated region (3′UTR) of the gene. Among them, 64 were classified as benign polymorphisms and 6 as VUS (variants of uncertain significance). Interestingly, seven pathogenic/likely pathogenic variants were identified in patients carrying a borderline or normal D4Z4 fragment size, namely c.182_183dupGT (p.Q62Vfs*48), c.2129dupC (p.A711Cfs*11), c.3469G>T (p.G1157*), c.5150_5151delAA (p.K1717Rfs*16) and c.1131+2_1131+5delTAAG, c.3010A>T (p.K1004*), c.853G>C (p.G285R). All of them were predicted to disrupt the structure and conformation of SMCHD1, resulting in the loss of GHKL-ATPase and SMC hinge essential domains. These results are consistent with the FSHD symptomatology and the Clinical Severity Score (CSS) of patients. In addition, five variants (c.*1376A>C, rs7238459; c.*1579G>A, rs559994; c.*1397A>G, rs150573037; c.*1631C>T, rs193227855; c.*1889G>C, rs149259359) were identified in the 3′UTR region of SMCHD1, suggesting a possible miRNA-dependent regulatory effect on FSHD-related pathways. The present study highlights the clinical utility of next-generation sequencing (NGS) platforms for the molecular diagnosis of FSHD and the importance of integrating molecular findings and clinical data in order to improve the accuracy of genotype–phenotype correlations.

scholarly journals Spectrum of Germline BRCA1 and BRCA2 Variants Identified in 2351 Ovarian and Breast Cancer Patients Referring to a Reference Cancer Hospital of Rome

Cancers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1286 ◽  
Author(s):  
Concetta Santonocito ◽  
Roberta Rizza ◽  
Ida Paris ◽  
Laura De Marchis ◽  
Carmela Paolillo ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Breast Cancer Patients ◽  
Brca1 And Brca2 ◽  
Pathogenic Variants ◽  
Uncertain Significance ◽  
In Vitro Diagnostic ◽  
Variant Frequency ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing

Pathogenic variants (PVs) carriers in BRCA1 or BRCA2 are associated with an elevated lifetime risk of developing breast cancer (BC) and/or ovarian cancer (OC). The prevalence of BRCA1 and BRCA2 germline alterations is extremely variable among different ethnic groups. Particularly, the rate of variants in Italian BC and/or OC families is rather controversial and ranges from 8% to 37%, according to different reports. By In Vitro Diagnostic (IVD) next generation sequencing (NGS)-based pipelines, we routinely screened thousands of patients with either sporadic or cancer family history. By NGS, we identified new PVs and some variants of uncertain significance (VUS) which were also evaluated in silico using dedicated tools. We report in detail data regarding BRCA1/2 variants identified in 517 out of 2351 BC and OC patients. The aim of this study was to report the incidence and spectrum of BRCA1/2 variants observed in BC and/or OC patients, tested in at Policlinico Gemelli Foundation Hospital, the origin of which is mainly from Central and Southern Italy. This study provides an overview of the variant frequency in these geographic areas of Italy and provides data that could be used in the clinical management of patients.

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.

scholarly journals A novel frequent BRCA1 recurrent variant c.5117G > A (p.Gly1206Glu) identified after 20 years of BRCA1/2 research in the Baltic region: cohort study and literature review

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
P. Loza ◽  
A. Irmejs ◽  
Z. Daneberga ◽  
E. Miklasevics ◽  
E. Berga-Svitina ◽  
...  
Keyword(s):  
Literature Review ◽  
Local Spectrum ◽  
Single Family ◽  
Baltic Region ◽  
Breast And Ovarian Cancer ◽  
Pathogenic Variants ◽  
Common Founder ◽  
The Baltic ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing

Abstract Background Several recent studies in the Baltic region have found extended spectrum of pathogenic variants (PV) of the BRCA1/2 genes. The aim of current study is to analyze the spectrum of the BRCA1/2 PV in population of Latvia and to compare common PV between populations of the Baltic region. Methods We present a cohort of 9543 unrelated individuals including ones with cancer and unaffected individuals from population of Latvia, who were tested for three most common BRCA1 founder PV. In second line testing, 164 founder negative high-risk individuals were tested for PV of the BRCA1/2 using next generation sequencing (NGS). Local spectrum of the BRCA1/2 PV was compared with the Baltic region by performing a literature review. Results Founder PV c.5266dupC, c.4035delA or c.181 T > G was detected in 369/9543 (3.9%) cases. Other BRCA1/2 PV were found in 44/164 (26.8%) of NGS cases. Four recurrent BRCA1 variants c.5117G > A (p.Gly1706Glu), c.4675G > A (p.Glu1559Lys), c.5503C > T (p.Arg1835*) and c.1961delA (p.Lys654fs) were detected in 18/44 (41.0%), 5/44 (11.4%), 2/44 (4.5%) and 2/44 (4.5%) cases respectively. Additionally, 11 BRCA1 PV and six BRCA2 PV were each found in single family. Conclusions By combining three studies by our group of the same cohort in Latvia, frequency of the BRCA1/2 PV for unselected breast and ovarian cancer cases is 241/5060 (4.8%) and 162/1067 (15.2%) respectively. The frequency of three “historical” founder PV is up to 87.0% (369/424). Other non-founder PV contribute to at least 13.0% (55/424) and this proportion probably will rise by increasing numbers of the BRCA1/2 sequencing. In relative numbers, c.5117G > A is currently the third most frequent PV of the BRCA1 in population of Latvia, overcoming previously known third most common founder variant c.181 T > G. In addition to three BRCA1 founder PV, a total of five recurrent BRCA1 and two recurrent BRCA2 PV have been reported in population of Latvia so far. Many of the BRCA1/2 PV reported in Latvia are shared among other populations of the Baltic region.

scholarly journals SMCHD1’s ubiquitin-like domain is required for N-terminal dimerization and chromatin localization

2021 ◽  
Author(s):  
Alexandra D Gurzau ◽  
Christopher Horne ◽  
Yee-Foong Mok ◽  
Megan Iminitoff ◽  
Tracy A Willson ◽  
...  
Keyword(s):  
Facioscapulohumeral Muscular Dystrophy ◽  
Chromatin Interaction ◽  
Structural Studies ◽  
Functional Importance ◽  
Targeted Deletion ◽  
Epigenetic Regulator ◽  
Biophysical Techniques ◽  
Structural Maintenance Of Chromosomes ◽  
Hinge Domain

Structural Maintenance of Chromosomes flexible Hinge Domain-containing 1 (SMCHD1) is an epigenetic regulator that mediates gene expression silencing at targeted sites across the genome. Our current understanding of SMCHD1’s molecular mechanism, and how substitutions within SMCHD1 lead to the diseases, facioscapulohumeral muscular dystrophy (FSHD) and Bosma arhinia microphthalmia syndrome (BAMS), are only emerging. Recent structural studies of its two component domains – the N-terminal ATPase and C-terminal SMC hinge – suggest that dimerization of each domain plays a central role in SMCHD1 function. Here, using biophysical techniques, we demonstrate that the SMCHD1 ATPase undergoes dimerization in a process that is dependent on both the N-terminal UBL (Ubiquitin-like) domain and ATP binding. We show that neither the dimerization event, nor the presence of a C-terminal extension past the transducer domain, affect SMCHD1’s in vitro catalytic activity as the rate of ATP turnover remains comparable to the monomeric protein. We further examined the functional importance of the N-terminal UBL domain in cells, revealing that its targeted deletion disrupts the localization of full-length SMCHD1 to chromatin. These findings implicate UBL-mediated SMCHD1 dimerization as a crucial step for chromatin interaction, and thereby for promoting SMCHD1-mediated gene silencing.

Assessment of Iron Overload in a Cohort of Sri Lankan Patients with Transfusion Dependent Beta Thalassaemia and its Correlation with Pathogenic Variants in HBB, HFE, SLC40A1, and TFR2 Genes

2021 ◽  
Author(s):  
Ruwangi Dissanayake ◽  
Nayana Samarasinghe ◽  
Samantha Waidyanatha ◽  
Sajeewani Pathirana ◽  
Vajira HW Dissanayake ◽  
...  
Keyword(s):  
Iron Overload ◽  
Serum Ferritin ◽  
Sri Lankan ◽  
Pathogenic Variants ◽  
Increased Risk ◽  
The Mean ◽  
One Year ◽  
Next Generation Sequencing Ngs ◽  
T2 Mri ◽  
Generation Sequencing

Abstract Background. Iron overload (IO) is a complication in transfusion dependent beta thalassaemmia (TDT). Pathogenic variants in genes involving iron metabolism may confer increased risk of IO. The objective of this study was to determine the magnitude of the cardiac and hepatic IO and determine whether pathogenic variants in HFE, SLC40A1 and TFR2 genes increase the risk of IO in a cohort of TDT patients in Sri Lanka.Materials and Methods. Fifty-seven (57) patients with TDT were recruited for this study. Serum ferritin was done once in 3 months for one year in all. Those who were ≥ 8 years of age underwent T2* MRI of the liver and heart. Fifty-two (52) patients underwent next generation sequencing (NGS) to identify pathogenic variants in HBB, HFE, SLC40A1 and TFR2 genes.Results. The mean age (SD) of this cohort was 9.5 (±4.6) years. It comprised of 30 (52.6%) boys and 27 (47.4%) girls. The mean serum ferritin was 3405 (±2670.5) ng/dl. Hepatic IO was seen in 38 (95%) patients and cardiac IO was seen in 17 (42.5%) patients. All patients with cardiac IO were asymptomatic and had normal echocardiogrammes. There was no statistically significant correlation between serum ferritin and hepatic or cardiac IO.32 (61.5%), 18 (34.6%), 2 (3.8%) of patients were homozygotes, compound heterozygotes and heterozygotes for pathogenic variants in the HBB gene. 9 (17.3%) and 3 (5.8%) patients were heterozygotes for pathogenic variants of HFE and SLC40A1 genes respectively. There were no pathogenic variants for the TfR2 gene. The heterozygotes of the pathogenic variants of the HFE and SLC40A1 genes were not at increased risk of IO.Conclusions. Cardiac T2* MRI helps to detect cardiac IO prior to the onset of symptoms when the echocardiogramme is normal. It is important to perform hepatic and cardiac MRI T2* to detect IO in patients with TDT.

scholarly journals Genetic Variants Detected Using Cell-Free DNA from Blood and Tumor Samples in Patients with Inflammatory Breast Cancer

2020 ◽  
Vol 21 (4) ◽  
pp. 1290
Author(s):  
Jennifer S. Winn ◽  
Zachary Hasse ◽  
Michael Slifker ◽  
Jianming Pei ◽  
Sebastian M. Arisi-Fernandez ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Inflammatory Breast Cancer ◽  
Triple Negative ◽  
Genetic Profile ◽  
Cell Free Dna ◽  
Targeted Next Generation Sequencing ◽  
Pathogenic Variants ◽  
Free Dna ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing

We studied genomic alterations in 19 inflammatory breast cancer (IBC) patients with advanced disease using samples of tissue and paired blood serum or plasma (cell-free DNA, cfDNA) by targeted next generation sequencing (NGS). At diagnosis, the disease was triple negative (TN) in eleven patients (57.8%), ER+ Her2- IBC in six patients (31.6%), ER+ Her2+ IBC in one patient (5.3%), and ER- Her2+ IBC in one other patient (5.3%). Pathogenic or likely pathogenic variants were frequently detected in TP53 (47.3%), PMS2 (26.3%), MRE11 (26.3%), RB1 (10.5%), BRCA1 (10.5%), PTEN (10.5%) and AR (10.5%); other affected genes included PMS1, KMT2C, BRCA2, PALB2, MUTYH, MEN1, MSH2, CHEK2, NCOR1, PIK3CA, ESR1 and MAP2K4. In 15 of the 19 patients in which tissue and paired blood were collected at the same time point, 80% of the variants detected in tissue were also detected in the paired cfDNA. Higher concordance between tissue and cfDNA was found for variants with higher allele fraction in tissue (AFtissue ≥ 5%). Furthermore, 86% of the variants detected in cfDNA were also detected in paired tissue. Our study suggests that the genetic profile measured in blood cfDNA is complementary to that of tumor tissue in IBC patients.

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 Using a Next Generation Sequencing Panel to Discover the Obscure Causes of Hereditary Hemolytic Anemias

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2433-2433 ◽  
Author(s):  
Archana M Agarwal ◽  
N. Scott Reading ◽  
Kimberly Frizzell ◽  
Wei Shen ◽  
Shelly Sorrells ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Hemolytic Anemia ◽  
Clinical Laboratory ◽  
Single Gene ◽  
Cytoskeletal Proteins ◽  
Next Generation ◽  
Pathogenic Variants ◽  
Late Morbidity ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing

Abstract Hereditary hemolytic anemias are a heterogeneous group of disorders with consequences ranging from non-anemic hemolysis to severe life-threatening anemia. However, the late morbidity in patients without transfusions is often underappreciated because of erythropoietic compensatory stimulation inducing hematopoiesis by erythroferrone/hepcidin axis. Principal causes of hereditary hemolytic anemias are germline mutations of red cell cytoskeleton (e.g. hereditary spherocytosis and elliptocytosis/pyropoikilocytosis) or enzyme deficiencies (e.g. Glucose 6 phosphate dehydrogenase deficiency and pyruvate kinase deficiency). Routine morphological and biochemical analysis may be inconclusive and misleading particularly in transfusion-dependent infants and children. Molecular studies have not been extensively used to diagnose these disorders due to the complex genetic nature of these disorders, and multi-gene disorders. In these cases, patients may undergo multiple rounds of single gene testing, which can be very costly and time consuming. The advent of next generation sequencing (NGS) methods in the clinical laboratory has made diagnosing complex genetic disorders feasible. Our diagnostic panel includes 28 genes encoding cytoskeletal proteins and enzymes, and covers the complete coding region, splice site junctions, and, where appropriate, deep intronic or regulatory regions. Targeted gene capture and library construction for next-generation sequencing (NGS) was performed using Sure Select kit (Agilent Technologies, Santa Clara, USA). Prior to sequencing on the Illumina Next Seq, (Illumina Inc) instrument, indexed samples are quantified using qPCR and then pooled. Samples were sequenced using 2x150 paired end sequencing. We now report the first 68 patients evaluated using our NGS panel. The age of the patients ranged from newborn to 62 years. These patients presented with symptoms ranging from mild lifelong anemia to severe hemolytic anemia with extreme hyperbilirubinemia. Genetic variants were classified using the American College of Medical Genetics (ACMG) guidelines. We identified pathogenic variants in 11 patients and likely pathogenic variants in 12 others, the majority of these were novel. Many variants with unknown significance were also identified that could potentially contribute to disease. The most commonly mutated genes were SPTB and SPTA1, encoding spectrin subunits. Some complex interactions were uncovered i.e. SPTA1 mutations along with alpha LELY leading to hereditary pyropoikilocytosis; Spectrin variants along with Gilbert syndrome causing severe hyperbilirubinemia in neonates; and Spectrin variants in combination with PKLR and G6PD variants. Our results demonstrate that many patients with hemolytic anemia harbor complex combinations of known and novel mutations in RBC cytoskeleton/enzyme genes, but their clinical significance is further augmented by polymorphisms of UGT1A1 gene contributing to severe neonatal hyperbilirubinemia and its consequences. To conclude, next-generation sequencing provides a cost-effective and relatively rapid approach to molecular diagnosis, especially in instances where traditional testing failed. We have used this technology successfully to determine the molecular causes of hemolytic anemia in many cases with no prior family history. Disclosures Yaish: Octapharma: Other: Study investigator.

scholarly journals Molecular profiling of congenital glioblastoma using a next-generation sequencing panel

2021 ◽  
Author(s):  
Débora Cabral de Carvalho Corrêa ◽  
Francine Tesser-Gamba ◽  
Nasjla da Silva ◽  
Andrea Capellano ◽  
Maria Teresa Alves ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Genetic Variants ◽  
Next Generation ◽  
Congenital Brain Tumor ◽  
Molecular Alterations ◽  
Pathogenic Variants ◽  
Pediatric Neoplasms ◽  
Tumor Entity ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing

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.

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