scholarly journals Complete genomic profiles of 1,496 Taiwanese reveal curated medical insights

2021 ◽  
Author(s):  
Dung-Chi Wu ◽  
Jacob Shujui Hsu ◽  
Chien-Yu Chen ◽  
Shang-Hung Shih ◽  
Jen-Feng Liu ◽  
...  
Keyword(s):  
Medical Information ◽  
Muscular Atrophy ◽  
Gene List ◽  
Genomic Medicine ◽  
Human Leukocyte ◽  
Carrier Status ◽  
Genomic Profile ◽  
Single Nucleotide Variants ◽  
Pathogenic Variants ◽  
Complete Genomic

Abstract Background Taiwan Biobank (TWB) project has built a nationwide database to facilitate the basic and clinical collaboration within the island and internationally, which is one of the valuable public datasets of the East Asian population. This study provided comprehensive genomic medicine findings from 1,496 WGS data from TWB. Methods We reanalyzed 1,496 Illumina-based whole genome sequences (WGS) of Taiwanese participants with at least 30X depth of coverage by Sentieon DNAscope, a precisionFDA challenge winner method. All single nucleotide variants (SNV) and small insertions/deletions 1 (Indel) have been jointly called and recalibrated as one cohort dataset. Multiple practicing clinicians have reviewed clinically significant variants. Results We found that each Taiwanese has 6,870.7 globally novel variants and classified all genomic positions according to the recalibrated sequence qualities. The variant quality score helps distinguish actual genetic variants among the technical false-positive variants, making the accurate variant minor allele frequency (MAF). All variant annotation information can be browsed at TaiwanGenomes (https://genomes.tw). We detected 54 PharmGKB-reported Cytochrome P450 (CYP) genes haplotype-drug pairs with MAF over 10% in the TWB cohort and 39.8% (439/1103) Taiwanese harbored at least one PharmGKB-reported human leukocyte antigen (HLA) risk allele. We also identified 23 variants located at ACMG secondary finding V3 gene list from 25 participants, indicating 1.67% of the population is harboring at least one medical actionable variant. For carrier status of all known pathogenic variants, we estimated one in 22 couples (4.52%) would be under the risk of having offspring with at least one pathogenic variant, which is in line with Japanese (JPN) and Singaporean (SGN) populations. We also detected 6.88% and 2.02% of carrier rates for alpha thalassemia and spinal muscular atrophy (SMA) for copy number pathogenic variants, respectively. Conclusion As WGS has become affordable for everyone, a person only needs to test once for a lifetime; comprehensive WGS data reanalysis of the genomic profile will have a significant clinical impact. Our study highlights the overall picture of a complete genomic profile with medical information for a population and individuals.

scholarly journals Diagnostic exome-based preconception carrier testing in consanguineous couples: results from the first 100 couples in clinical practice

2021 ◽  
Author(s):  
Suzanne C. E. H. Sallevelt ◽  
Alexander P. A. Stegmann ◽  
Bart de Koning ◽  
Crool Velter ◽  
Anja Steyls ◽  
...  
Keyword(s):  
Autosomal Recessive ◽  
Rare Variants ◽  
Clinical Care ◽  
Carrier Testing ◽  
Carrier Status ◽  
Routine Diagnostics ◽  
Affected Offspring ◽  
Pathogenic Variants ◽  
Increased Risk ◽  
Genetics And Genomics

Abstract Purpose Consanguineous couples are at increased risk of being heterozygous for the same autosomal recessive (AR) disorder(s), with a 25% risk of affected offspring as a consequence. Until recently, comprehensive preconception carrier testing (PCT) for AR disorders was unavailable in routine diagnostics. Here we developed and implemented such a test in routine clinical care. Methods We performed exome sequencing (ES) for 100 consanguineous couples. For each couple, rare variants that could give rise to biallelic variants in offspring were selected. These variants were subsequently filtered against a gene panel consisting of ~2,000 genes associated with known AR disorders (OMIM-based). Remaining variants were classified according to American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) guidelines, after which only likely pathogenic and pathogenic (class IV/V) variants, present in both partners, were reported. Results In 28 of 100 tested consanguineous couples (28%), likely pathogenic and pathogenic variants not previously known in the couple or their family were reported conferring 25% risk of affected offspring. Conclusion ES-based PCT provides a powerful diagnostic tool to identify AR disease carrier status in consanguineous couples. Outcomes provided significant reproductive choices for a higher proportion of these couples than previous tests.

scholarly journals nanotatoR: a tool for enhanced annotation of genomic structural variants

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Surajit Bhattacharya ◽  
Hayk Barseghyan ◽  
Emmanuèle C. Délot ◽  
Eric Vilain
Keyword(s):  
De Novo ◽  
Genome Mapping ◽  
Gene List ◽  
Sufficient Information ◽  
Rna Seq ◽  
Structural Variants ◽  
De Novo Genome Assembly ◽  
Pathogenic Variants ◽  
Increased Sensitivity

Abstract Background Whole genome sequencing is effective at identification of small variants, but because it is based on short reads, assessment of structural variants (SVs) is limited. The advent of Optical Genome Mapping (OGM), which utilizes long fluorescently labeled DNA molecules for de novo genome assembly and SV calling, has allowed for increased sensitivity and specificity in SV detection. However, compared to small variant annotation tools, OGM-based SV annotation software has seen little development, and currently available SV annotation tools do not provide sufficient information for determination of variant pathogenicity. Results We developed an R-based package, nanotatoR, which provides comprehensive annotation as a tool for SV classification. nanotatoR uses both external (DGV; DECIPHER; Bionano Genomics BNDB) and internal (user-defined) databases to estimate SV frequency. Human genome reference GRCh37/38-based BED files are used to annotate SVs with overlapping, upstream, and downstream genes. Overlap percentages and distances for nearest genes are calculated and can be used for filtration. A primary gene list is extracted from public databases based on the patient’s phenotype and used to filter genes overlapping SVs, providing the analyst with an easy way to prioritize variants. If available, expression of overlapping or nearby genes of interest is extracted (e.g. from an RNA-Seq dataset, allowing the user to assess the effects of SVs on the transcriptome). Most quality-control filtration parameters are customizable by the user. The output is given in an Excel file format, subdivided into multiple sheets based on SV type and inheritance pattern (INDELs, inversions, translocations, de novo, etc.). nanotatoR passed all quality and run time criteria of Bioconductor, where it was accepted in the April 2019 release. We evaluated nanotatoR’s annotation capabilities using publicly available reference datasets: the singleton sample NA12878, mapped with two types of enzyme labeling, and the NA24143 trio. nanotatoR was also able to accurately filter the known pathogenic variants in a cohort of patients with Duchenne Muscular Dystrophy for which we had previously demonstrated the diagnostic ability of OGM. Conclusions The extensive annotation enables users to rapidly identify potential pathogenic SVs, a critical step toward use of OGM in the clinical setting.

scholarly journals Unsuspected somatic mosaicism for FBN1 gene contributes to Marfan syndrome

2021 ◽  
Author(s):  
Pauline Arnaud ◽  
Hélène Morel ◽  
Olivier Milleron ◽  
Laurent Gouya ◽  
Christine Francannet ◽  
...  
Keyword(s):  
Marfan Syndrome ◽  
Somatic Mosaicism ◽  
Variant Calling ◽  
Copy Number Variations ◽  
Pathogenic Variant ◽  
Single Nucleotide Variants ◽  
Bioinformatics Analyses ◽  
Single Nucleotide ◽  
Fbn1 Gene ◽  
Pathogenic Variants

Abstract Purpose Individuals with mosaic pathogenic variants in the FBN1 gene are mainly described in the course of familial screening. In the literature, almost all these mosaic individuals are asymptomatic. In this study, we report the experience of our team on more than 5,000 Marfan syndrome (MFS) probands. Methods Next-generation sequencing (NGS) capture technology allowed us to identify five cases of MFS probands who harbored a mosaic pathogenic variant in the FBN1 gene. Results These five sporadic mosaic probands displayed classical features usually seen in Marfan syndrome. Combined with the results of the literature, these rare findings concerned both single-nucleotide variants and copy-number variations. Conclusion This underestimated finding should not be overlooked in the molecular diagnosis of MFS patients and warrants an adaptation of the parameters used in bioinformatics analyses. The five present cases of symptomatic MFS probands harboring a mosaic FBN1 pathogenic variant reinforce the fact that apparently asymptomatic mosaic parents should have a complete clinical examination and a regular cardiovascular follow-up. We advise that individuals with a typical MFS for whom no single-nucleotide pathogenic variant or exon deletion/duplication was identified should be tested by NGS capture panel with an adapted variant calling analysis.

scholarly journals Rare Germline Variants in Chordoma-Related Genes and Chordoma Susceptibility

Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2704
Author(s):  
Sally Yepes ◽  
Nirav N. Shah ◽  
Jiwei Bai ◽  
Hela Koka ◽  
Chuzhong Li ◽  
...  
Keyword(s):  
Internal Control ◽  
Susceptibility Gene ◽  
Copy Number Variants ◽  
Bone Cancer ◽  
Chinese Patients ◽  
European Ancestry ◽  
Unknown Etiology ◽  
Loss Of Function ◽  
Single Nucleotide Variants ◽  
Pathogenic Variants

Background: Chordoma is a rare bone cancer with an unknown etiology. TBXT is the only chordoma susceptibility gene identified to date; germline single nucleotide variants and copy number variants in TBXT have been associated with chordoma susceptibility in familial and sporadic chordoma. However, the genetic susceptibility of chordoma remains largely unknown. In this study, we investigated rare germline genetic variants in genes involved in TBXT/chordoma-related signaling pathways and other biological processes in chordoma patients from North America and China. Methods: We identified variants that were very rare in general population and internal control datasets and showed evidence for pathogenicity in 265 genes in a whole exome sequencing (WES) dataset of 138 chordoma patients of European ancestry and in a whole genome sequencing (WGS) dataset of 80 Chinese patients with skull base chordoma. Results: Rare and likely pathogenic variants were identified in 32 of 138 European ancestry patients (23%), including genes that are part of notochord development, PI3K/AKT/mTOR, Sonic Hedgehog, SWI/SNF complex and mesoderm development pathways. Rare pathogenic variants in COL2A1, EXT1, PDK1, LRP2, TBXT and TSC2, among others, were also observed in Chinese patients. Conclusion: We identified several rare loss-of-function and predicted deleterious missense variants in germline DNA from patients with chordoma, which may influence chordoma predisposition and reflect a complex susceptibility, warranting further investigation in large studies.

scholarly journals Genotype-Phenotype Correlations in Neurofibromatosis Type 1: A Single-Center Cohort Study

Cancers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1879
Author(s):  
Marcello Scala ◽  
Irene Schiavetti ◽  
Francesca Madia ◽  
Cristina Chelleri ◽  
Gianluca Piccolo ◽  
...  
Keyword(s):  
Neurofibromatosis Type 1 ◽  
Neurofibromatosis Type ◽  
Copy Number Variations ◽  
Single Nucleotide Variants ◽  
Multivariate Statistical ◽  
Gene Deletions ◽  
Pathogenic Variants ◽  
Lisch Nodules ◽  
Next Generation Sequencing Ngs

Neurofibromatosis type 1 (NF1) is a proteiform genetic condition caused by pathogenic variants in NF1 and characterized by a heterogeneous phenotypic presentation. Relevant genotype–phenotype correlations have recently emerged, but only few pertinent studies are available. We retrospectively reviewed clinical, instrumental, and genetic data from a cohort of 583 individuals meeting at least 1 diagnostic National Institutes of Health (NIH) criterion for NF1. Of these, 365 subjects fulfilled ≥2 NIH criteria, including 235 pediatric patients. Genetic testing was performed through cDNA-based sequencing, Next Generation Sequencing (NGS), and Multiplex Ligation-dependent Probe Amplification (MLPA). Uni- and multivariate statistical analysis was used to investigate genotype–phenotype correlations. Among patients fulfilling ≥ 2 NIH criteria, causative single nucleotide variants (SNVs) and copy number variations (CNVs) were detected in 267/365 (73.2%) and 20/365 (5.5%) cases. Missense variants negatively correlated with neurofibromas (p = 0.005). Skeletal abnormalities were associated with whole gene deletions (p = 0.05) and frameshift variants (p = 0.006). The c.3721C>T; p.(R1241*) variant positively correlated with structural brain alterations (p = 0.031), whereas Lisch nodules (p = 0.05) and endocrinological disorders (p = 0.043) were associated with the c.6855C>A; p.(Y2285*) variant. We identified novel NF1 genotype–phenotype correlations and provided an overview of known associations, supporting their potential relevance in the implementation of patient management.

scholarly journals Re-evaluation of single nucleotide variants and identification of structural variants in a cohort of 45 sudden unexplained death cases

2021 ◽  
Author(s):  
Jacqueline Neubauer ◽  
Shouyu Wang ◽  
Giancarlo Russo ◽  
Cordula Haas
Keyword(s):  
Sudden Death ◽  
Cardiac Diseases ◽  
Structural Variants ◽  
Single Nucleotide Variants ◽  
Single Nucleotide ◽  
Sudden Unexplained Death ◽  
Unexplained Death ◽  
Pathogenic Variants ◽  
The Impact ◽  
Death Cases

AbstractSudden unexplained death (SUD) takes up a considerable part in overall sudden death cases, especially in adolescents and young adults. During the past decade, many channelopathy- and cardiomyopathy-associated single nucleotide variants (SNVs) have been identified in SUD studies by means of postmortem molecular autopsy, yet the number of cases that remain inconclusive is still high. Recent studies had suggested that structural variants (SVs) might play an important role in SUD, but there is no consensus on the impact of SVs on inherited cardiac diseases. In this study, we searched for potentially pathogenic SVs in 244 genes associated with cardiac diseases. Whole-exome sequencing and appropriate data analysis were performed in 45 SUD cases. Re-analysis of the exome data according to the current ACMG guidelines identified 14 pathogenic or likely pathogenic variants in 10 (22.2%) out of the 45 SUD cases, whereof 2 (4.4%) individuals had variants with likely functional effects in the channelopathy-associated genes SCN5A and TRDN and 1 (2.2%) individual in the cardiomyopathy-associated gene DTNA. In addition, 18 structural variants (SVs) were identified in 15 out of the 45 individuals. Two SVs with likely functional impairment were found in the coding regions of PDSS2 and TRPM4 in 2 SUD cases (4.4%). Both were identified as heterozygous deletions, which were confirmed by multiplex ligation-dependent probe amplification. In conclusion, our findings support that SVs could contribute to the pathology of the sudden death event in some of the cases and therefore should be investigated on a routine basis in suspected SUD cases.

Intrafamilial Variability of the R694C Variant in BICD2 Presenting with Lethal Severe Arthrogryposis

2022 ◽  
pp. 097321792110688
Author(s):  
Francisco Ribeiro-Mourão ◽  
Ana Vilan ◽  
Sara Passos-Silva ◽  
Fernando Silveira ◽  
Miguel Leão ◽  
...  
Keyword(s):  
De Novo ◽  
Bone Fractures ◽  
Muscular Atrophy ◽  
Hip Dislocation ◽  
Arthrogryposis Multiplex Congenita ◽  
Pathogenic Variants ◽  
Genetic Abnormalities ◽  
Heterozygous Variant ◽  
Fetal Movements ◽  
Intrafamilial Variability

Arthrogryposis multiplex congenita (AMC) is a heterogeneous condition comprising congenital multiple joint contractures, and it is secondary to decreased fetal mobility following environmental/genetic abnormalities. BICD2 pathogenic variants have been associated with autosomal dominant spinal muscular atrophy with lower extremity predominance (SMALED2). We report the case of a newborn with decreased fetal movements and ventriculomegaly diagnosed in utero, born with severe AMC, multiple bone fractures, congenital hip dislocation, and respiratory insufficiency that led to neonatal death. His mother had AMC diagnosis without established etiology. Her phenotype characterization was key to guide the genetic investigation. A BICD 2 heterozygous variant (NM_001003800.1; c.2080C > T; p. [Arg694Cys]) was detected both in the mother and the newborn. This variant had previously been reported in 3 cases, all having de novo severe SMALED-type 2B (MIM#618291) phenotype. This is the first report of this variant (p. [Arg694Cys]) presenting with an inherited, severe, and lethal phenotype associated to intrafamilial variability, suggesting a more complex phenotype-genotype correlation than previously stated.

scholarly journals Contribution of Genetic and Environmental Risk Factors in a Juvenile Idiopathic Arthritis Large Family With SERPINA1 Gene Mutations

2021 ◽  
Author(s):  
Cyprian Popescu
Keyword(s):  
Juvenile Idiopathic Arthritis ◽  
Gene Mutations ◽  
Large Family ◽  
Carrier Status ◽  
Multiplex Family ◽  
Serpina1 Gene ◽  
Pathogenic Variants ◽  
Whole Exome ◽  
Genetic And Environmental Factors ◽  
Underlying Mechanisms

Abstract Objectives Although the underlying mechanisms and mediators of arthritis in juvenile idiopathic arthritis (JIA) are not well understood, accumulated evidence supports the mixt role of genetic and environmental factors. Few reports of multiplex families with JIA were published until now. The aim of this study was to identify new genetic or environmental associations concerning the patients of a kindred with juvenile idiopathic arthritis and psoriatic features (JIAPs). Methods Here, we characterized an extended multiplex family of 5 patients with juvenile idiopathic arthritis and psoriatic features (PsA) at the clinical and genetic level, using whole exome sequencing. Results We did not confirm in our family the linkage with the genetic factors already described that might be associated with increase susceptibility to JIA. We found a carrier status of siblings who inherited a pathogenic allele of the SERPINA1 gene from their mother who herself has two heterozygous pathogenic variants in the SERPINA1 gene. Conclusions Our data showed that JIA results from pleiotropic effects of environmental background with an only minor monogenic contribution. Even that a monogenetic factor could not be proved, some genetic factor as SERPINA1 mutations which can sensitize for psoriatic arthritis development seems to be involved. Further investigation must be done to prove whether SERPINA1 mutations may have a potential JIA causality.

scholarly journals A scalable EHR-based approach for phenotype discovery and variant interpretation for hereditary cancer genes

2021 ◽  
Author(s):  
Chenjie Zeng ◽  
Lisa A Bastarache ◽  
Ran Tao ◽  
Eric Venner ◽  
Scott Hebbring ◽  
...  
Keyword(s):  
Hereditary Cancer ◽  
Meta Analysis ◽  
Genetic Disorders ◽  
Genomic Medicine ◽  
Risk Scores ◽  
Cancer Genes ◽  
Pathogenic Variants ◽  
Emerge Network ◽  
Uncertain Significance ◽  
Potential Pathogenicity

Knowledge of the clinical spectrum of rare genetic disorders helps in disease management and variant pathogenicity interpretation. Leveraging electronic health record (EHR)-linked genetic testing data from the eMERGE network, we determined the associations between a set of 23 hereditary cancer genes and 3017 phenotypes in 23544 individuals. This phenome-wide association study replicated 45% (184/406) of known gene-phenotype associations (P = 5.1 ×10-125). Meta-analysis with an independent EHR-derived cohort of 3242 patients confirmed 14 novel associations with phenotypes in the neoplastic, genitourinary, digestive, congenital, metabolic, mental and neurologic categories. Phenotype risk scores (PheRS) based on weighted aggregations of EHR phenotypes accurately predicted variant pathogenicity for at least 50% of pathogenic variants for 8/23 genes. We generated a catalog of PheRS for 7800 variants, including 5217 variants of uncertain significance, to provide empirical evidence of potential pathogenicity. This study highlights the potential of EHR data in genomic medicine.

scholarly journals Information and genetic counselling for psychiatric risks in children with rare genomic disorders

2019 ◽  
Author(s):  
Andrew Cuthbert ◽  
Aimee Challenger ◽  
Jeremy Hall ◽  
Marianne BM van den Bree
Keyword(s):  
Genetic Counselling ◽  
Online Survey ◽  
Genomic Medicine ◽  
Genetic Diagnosis ◽  
Single Nucleotide Variants ◽  
Full Spectrum ◽  
Face To Face ◽  
Professional Information ◽  
Genomic Disorders ◽  
Psychiatric Manifestations

AbstractPurposeGenomic medicine has transformed the diagnosis of neurodevelopmental disorders. Evidence of increased psychiatric comorbidity associated with genomic copy number and single nucleotide variants (CNV and SNV) may not be fully considered when providing genetic counselling. We explored parents’ experiences of genetics services and how they obtained information concerning psychiatric manifestations.MethodsParents of children diagnosed with genomic variants completed an online survey exploring, (i) how they experienced the genetic diagnosis, and (ii) how they acquired information about psychiatric, developmental and physical manifestations.ResultsTwo-hundred and 86 respondents completed the survey. Thirty percent were unsatisfied with receiving genetic diagnoses. Satisfaction was predicted if communication was by geneticists (p = 0.004); provided face-to-face (p = 0.003); clearly explained (p < 0.001); and accompanied by support (p = 0.017). Parents obtained psychiatric information from non-professional sources more often than developmental (ϕ 0.26, p < 0.001) and physical manifestations (ϕ 0.21, p = 0.003), which mostly came from health professionals. Information from support organisations was more helpful than from geneticists (odds ratio [OR] 21.0, 95% CI 5.1 – 86.8, p < 0.001); paediatricians (OR 11.0, 1.4 – 85.2, p = 0.004); and internet sites (OR 15.5, 3.7 – 64.8, p < 0.001).ConclusionA paucity of professional information about psychiatric risks after genetic diagnosis may impede early diagnosis and intervention for children with high genotypic risks. Planned integration of genomic testing into mainstream services should include genetic counselling training to address the full spectrum of developmental, physical and psychiatric manifestations and timely provision of high-quality information.

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