scholarly journals Automated prediction of the clinical impact of structural copy number variations

2020 ◽  
Author(s):  
Michaela Gaziova ◽  
Tomas Sladecek ◽  
Ondrej Pos ◽  
Martin Stevko ◽  
Werner Krampl ◽  
...  
Keyword(s):  
Copy Number ◽  
Genetic Diseases ◽  
Copy Number Variants ◽  
Copy Number Gain ◽  
Regulatory Elements ◽  
Copy Number Variations ◽  
Clinical Impact ◽  
Copy Number Loss ◽  
Pathogenicity Prediction

Introduction: Copy number variants (CNVs) play an important role in many biological processes, including the development of genetic diseases, making them attractive targets for genetic analyses. The interpretation of the effect of structural variants is a challenging problem due to highly variable numbers of gene, regulatory or other genomic elements affected by the CNV. This led to the demand for the interpretation tools that would relieve researchers, laboratory diagnosticians, genetic counselors, and clinical geneticists from the laborious process of annotation and classification of CNVs. Materials and Methods: We designed a classifier method based on the annotations of CNVs from several publicly available databases. The attributes take into account gene elements, regulatory elements affected by the CNV, as well as other CNVs with known clinical significance that overlap the candidate CNV. We also describe the process of model selection and the construction of training, validation, and test set. Results: The presented approach achieved more than 98% prediction accuracy on both copy number loss and copy number gain variants and can be improved by imposing probability thresholds to eliminate low confidence predictions. Discussion: Method has shown considerable performance in predicting the clinical impact of CNVs and therefore has a great potential to guide users to more precise conclusions. The CNV annotation and pathogenicity prediction can be fully automated, relieving users of tedious interpretation processes. Availability and Implementation: The results can be reproduced by following instructions at {{https://github.com/tsladecek/isv}}.

scholarly journals Automated prediction of the clinical impact of structural copy number variations

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
M. Gažiová ◽  
T. Sládeček ◽  
O. Pös ◽  
M. Števko ◽  
W. Krampl ◽  
...  
Keyword(s):  
Copy Number ◽  
Genetic Diseases ◽  
Copy Number Variants ◽  
Prediction Method ◽  
Copy Number Gain ◽  
Copy Number Variations ◽  
Copy Number Loss ◽  
Structural Variants ◽  
Uncertain Significance

AbstractCopy number variants (CNVs) play an important role in many biological processes, including the development of genetic diseases, making them attractive targets for genetic analyses. The interpretation of the effect of these structural variants is a challenging problem due to highly variable numbers of gene, regulatory, or other genomic elements affected by the CNV. This led to the demand for the interpretation tools that would relieve researchers, laboratory diagnosticians, genetic counselors, and clinical geneticists from the laborious process of annotation and classification of CNVs. We designed and validated a prediction method (ISV; Interpretation of Structural Variants) that is based on boosted trees which takes into account annotations of CNVs from several publicly available databases. The presented approach achieved more than 98% prediction accuracy on both copy number loss and copy number gain variants while also allowing CNVs being assigned “uncertain” significance in predictions. We believe that ISV’s prediction capability and explainability have a great potential to guide users to more precise interpretations and classifications of CNVs.

Automated classification of copy number variants based on 2019 ACMG standards

2021 ◽  
Vol 132 ◽  
pp. S287-S288
Author(s):  
Jianling Ji ◽  
Ryan Schmidt ◽  
Westley Sherman ◽  
Ryan Peralta ◽  
Megan Roytman ◽  
...  
Keyword(s):  
Copy Number ◽  
Copy Number Variants ◽  
Automated Classification

scholarly journals Combination of Genome-Wide Polymorphisms and Copy Number Variations of Pharmacogenes in Koreans

2021 ◽  
Vol 11 (1) ◽  
pp. 33
Author(s):  
Nayoung Han ◽  
Jung Mi Oh ◽  
In-Wha Kim
Keyword(s):  
Copy Number ◽  
Genome Wide Association Study ◽  
Copy Number Gain ◽  
Copy Number Variations ◽  
Gene Gain ◽  
Single Nucleotide Variants ◽  
Single Nucleotide ◽  
Haplotype Blocks ◽  
Genome Wide ◽  
Control And Prevention

For predicting phenotypes and executing precision medicine, combination analysis of single nucleotide variants (SNVs) genotyping with copy number variations (CNVs) is required. The aim of this study was to discover SNVs or common copy CNVs and examine the combined frequencies of SNVs and CNVs in pharmacogenes using the Korean genome and epidemiology study (KoGES), a consortium project. The genotypes (N = 72,299) and CNV data (N = 1000) were provided by the Korean National Institute of Health, Korea Centers for Disease Control and Prevention. The allele frequencies of SNVs, CNVs, and combined SNVs with CNVs were calculated and haplotype analysis was performed. CYP2D6 rs1065852 (c.100C>T, p.P34S) was the most common variant allele (48.23%). A total of 8454 haplotype blocks in 18 pharmacogenes were estimated. DMD ranked the highest in frequency for gene gain (64.52%), while TPMT ranked the highest in frequency for gene loss (51.80%). Copy number gain of CYP4F2 was observed in 22 subjects; 13 of those subjects were carriers with CYP4F2*3 gain. In the case of TPMT, approximately one-half of the participants (N = 308) had loss of the TPMT*1*1 diplotype. The frequencies of SNVs and CNVs in pharmacogenes were determined using the Korean cohort-based genome-wide association study.

scholarly journals The clinical impact of copy number variants in inherited bone marrow failure syndromes

2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Nicolas Waespe ◽  
Santhosh Dhanraj ◽  
Manju Wahala ◽  
Elena Tsangaris ◽  
Tom Enbar ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Copy Number ◽  
Bone Marrow Failure ◽  
Copy Number Variants ◽  
Clinical Impact ◽  
Bone Marrow Failure Syndromes

scholarly journals Genotype-Phenotype correlation in Dravet Syndrome with SCN1A mutation increase efficiency of molecular diagnosis

2012 ◽  
Vol 18 (2) ◽  
pp. 60-62
Author(s):  
MC Gonsales ◽  
P Preto ◽  
MA Montenegro ◽  
MM Guerreiro ◽  
I Lopes-Cendes
Keyword(s):  
Protein Function ◽  
Copy Number ◽  
Mutation Screening ◽  
Copy Number Variants ◽  
Febrile Seizures ◽  
Copy Number Variations ◽  
Dravet Syndrome ◽  
Missense Mutations ◽  
The Impact ◽  
Doose Syndrome

OBJECTIVES: The purpose of this study was to advance the knowledge on the clinical use of SCN1A testing for severe epilepsies within the spectrum of generalized epilepsy with febrile seizures plus by performing genetic screening in patients with Dravet and Doose syndromes and establishing genotype-phenotype correlations. METHODS: Mutation screening in SCN1A was performed in 15 patients with Dravet syndrome and 13 with Doose syndrome. Eight prediction algorithms were used to analyze the impact of the mutations in putative protein function. Furthermore, all SCN1A mutations previously published were compiled and analyzed. In addition, Multiplex Ligation-Dependent Probe Amplification (MLPA) technique was used to detect possible copy number variations within SCN1A. RESULTS: Twelve mutations were identified in patients with Dravet syndrome, while patients with Doose syndrome showed no mutations. Our results show that the most common type of mutation found is missense, and that they are mostly located in the pore region and the N- and C-terminal of the protein. No copy number variants in SCN1A were identified in our cohort. CONCLUSIONS: SCN1A testing is clinically useful for patients with Dravet syndrome, but not for those with Doose syndrome, since both syndromes do not seem to share the same genetic basis. Our results indicate that indeed missense mutations can cause severe phenotypes depending on its location and the type of amino-acid substitution. Moreover, our strategy for predicting deleterious effect of mutations using multiple computation algorithms was efficient for most of the mutations identified.

scholarly journals Bayesian copy number detection and association in large-scale studies

2020 ◽  
Author(s):  
Stephen Cristiano ◽  
David McKean ◽  
Jacob Carey ◽  
Paige Bracci ◽  
Paul Brennan ◽  
...  
Keyword(s):  
Copy Number ◽  
Large Scale ◽  
Disease Risk ◽  
Copy Number Variants ◽  
Regulatory Elements ◽  
Cancer Case ◽  
Tumor Supressor ◽  
Increase Risk ◽  
Control Study

AbstractGermline copy number variants (CNVs) increase risk for many diseases, yet detection of CNVs and quantifying their contribution to disease risk in large-scale studies is challenging. We developed an approach called CNPBayes to identify latent batch effects, to provide probabilistic estimates of integer copy number across the estimated batches, and to fully integrate the copy number uncertainty in the association model for disease. We demonstrate this approach in a Pancreatic Cancer Case Control study of 7,598 participants where the major sources of technical variation were not captured by study site and varied across the genome. Candidate associations aided by this approach include deletions of 8q24 near regulatory elements of the tumor oncogene MYC and of Tumor Supressor Candidate 3 (TUSC3). This study provides a robust Bayesian inferential framework for estimating copy number and evaluating the role of copy number in heritable diseases.

scholarly journals CNV-P: a machine-learning framework for predicting high confident copy number variations

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12564
Author(s):  
Taifu Wang ◽  
Jinghua Sun ◽  
Xiuqing Zhang ◽  
Wen-Jing Wang ◽  
Qing Zhou
Keyword(s):  
Machine Learning ◽  
False Positive ◽  
Copy Number ◽  
Genetic Disorders ◽  
Genetic Diseases ◽  
Basic Research ◽  
Read Depth ◽  
Copy Number Variations ◽  
Sequencing Data ◽  
Learning Framework

Background Copy-number variants (CNVs) have been recognized as one of the major causes of genetic disorders. Reliable detection of CNVs from genome sequencing data has been a strong demand for disease research. However, current software for detecting CNVs has high false-positive rates, which needs further improvement. Methods Here, we proposed a novel and post-processing approach for CNVs prediction (CNV-P), a machine-learning framework that could efficiently remove false-positive fragments from results of CNVs detecting tools. A series of CNVs signals such as read depth (RD), split reads (SR) and read pair (RP) around the putative CNV fragments were defined as features to train a classifier. Results The prediction results on several real biological datasets showed that our models could accurately classify the CNVs at over 90% precision rate and 85% recall rate, which greatly improves the performance of state-of-the-art algorithms. Furthermore, our results indicate that CNV-P is robust to different sizes of CNVs and the platforms of sequencing. Conclusions Our framework for classifying high-confident CNVs could improve both basic research and clinical diagnosis of genetic diseases.

scholarly journals Pmp22 super-enhancer deletion causes tomacula formation and conduction block in peripheral nerves

2020 ◽  
Vol 29 (10) ◽  
pp. 1689-1699
Author(s):  
Harrison Pantera ◽  
Bo Hu ◽  
Daniel Moiseev ◽  
Chris Dunham ◽  
Jibraan Rashid ◽  
...  
Keyword(s):  
Peripheral Neuropathy ◽  
Schwann Cell ◽  
Copy Number ◽  
Regulatory Elements ◽  
Copy Number Variations ◽  
Hereditary Neuropathy ◽  
Peripheral Myelin Protein 22 ◽  
Super Enhancer

Abstract Copy number variation of the peripheral nerve myelin gene Peripheral Myelin Protein 22 (PMP22) causes multiple forms of inherited peripheral neuropathy. The duplication of a 1.4 Mb segment surrounding this gene in chromosome 17p12 (c17p12) causes the most common form of Charcot-Marie-Tooth disease type 1A, whereas the reciprocal deletion of this gene causes a separate neuropathy termed hereditary neuropathy with liability to pressure palsies (HNPP). PMP22 is robustly induced in Schwann cells in early postnatal development, and several transcription factors and their cognate regulatory elements have been implicated in coordinating the gene’s proper expression. We previously found that a distal super-enhancer domain was important for Pmp22 expression in vitro, with particular impact on a Schwann cell-specific alternative promoter. Here, we investigate the consequences of deleting this super-enhancer in vivo. We find that loss of the super-enhancer in mice reduces Pmp22 expression throughout development and into adulthood, with greater impact on the Schwann cell-specific promoter. Additionally, these mice display tomacula formed by excessive myelin folding, a pathological hallmark of HNPP, as have been previously observed in heterozygous Pmp22 mice as well as sural biopsies from patients with HNPP. Our findings demonstrate a mechanism by which smaller copy number variations, not including the Pmp22 gene, are sufficient to reduce gene expression and phenocopy a peripheral neuropathy caused by the HNPP-associated deletion encompassing PMP22.

scholarly journals A Simple, Universal, and Cost-Efficient Digital PCR Method for the Targeted Analysis of Copy Number Variations

2019 ◽  
Vol 65 (9) ◽  
pp. 1153-1160 ◽  
Author(s):  
Kévin Cassinari ◽  
Olivier Quenez ◽  
Géraldine Joly-Hélas ◽  
Ludivine Beaussire ◽  
Nathalie Le Meur ◽  
...  
Keyword(s):  
Copy Number ◽  
Segregation Analysis ◽  
Genetic Diseases ◽  
Genomic Medicine ◽  
Digital Pcr ◽  
Copy Number Variations ◽  
Locked Nucleic Acid ◽  
Targeted Analysis ◽  
Cost Efficient ◽  
High Flexibility

Abstract BACKGROUND Rare copy number variations (CNVs) are a major cause of genetic diseases. Simple targeted methods are required for their confirmation and segregation analysis. We developed a simple and universal CNV assay based on digital PCR (dPCR) and universal locked nucleic acid (LNA) hydrolysis probes. METHODS We analyzed the mapping of the 90 LNA hydrolysis probes from the Roche Universal ProbeLibrary (UPL). For each CNV, selection of the optimal primers and LNA probe was almost automated; probes were reused across assays and each dPCR assay included the CNV amplicon and a reference amplicon. We assessed the assay performance on 93 small and large CNVs and performed a comparative cost-efficiency analysis. RESULTS UPL-LNA probes presented nearly 20000000 occurrences on the human genome and were homogeneously distributed with a mean interval of 156 bp. The assay accurately detected all the 93 CNVs, except one (<200 bp), with coefficient of variation <10%. The assay was more cost-efficient than all the other methods. CONCLUSIONS The universal dPCR CNV assay is simple, robust, and cost-efficient because it combines a straightforward design allowed by universal probes and end point PCR, the advantages of a relative quantification of the target to the reference within the same reaction, and the high flexibility of the LNA hydrolysis probes. This method should be a useful tool for genomic medicine, which requires simple methods for the interpretation and segregation analysis of genomic variations.

Molecular karyotyping in routine diagnostics – a view back and forth1)

2013 ◽  
Vol 36 (5) ◽  
Author(s):  
Uwe Heinrich ◽  
Meike Gabert ◽  
Imma Rost
Keyword(s):  
Copy Number ◽  
Copy Number Variants ◽  
Uniparental Disomy ◽  
Simultaneous Detection ◽  
Molecular Karyotyping ◽  
Comparative Genomic ◽  
Detection Rates ◽  
Routine Diagnostics ◽  
Indispensable Tool

AbstractSince its introduction in the routine diagnostics of patients with mental retardation/developmental delay, array-comparative genomic hybridization (aCGH) has become an indispensable tool for the detection of clinically relevant copy number variants (CNVs). Despite the current tendency for higher resolution arrays, the growing number of public internet databases as well as better calling algorithms allow save reporting and a better classification of CNVs. The application of combined aCGH plus single nucleotide polymorphism (SNP) arrays will increase detection rates by revealing copy number neutral changes, such as uniparental disomy. In the future, next generation sequencing techniques will lead to a further increase in resolution with the simultaneous detection of unbalanced and even balanced chromosomal aberrations.

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