scholarly journals In-silico phenotype prediction by normal mode variant analysis in TUBB4A-related disease

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Avi Fellner ◽  
Yael Goldberg ◽  
Dorit Lev ◽  
Lina Basel-Salmon ◽  
Oded Shor ◽  
...  
Keyword(s):  
Normal Mode ◽  
In Silico ◽  
Coarse Grained ◽  
Mode Analysis ◽  
Variant Interpretation ◽  
Wild Type ◽  
Phenotype Prediction ◽  
Missense Variants ◽  
Related Disease ◽  
Pathogenic Variants

AbstractTUBB4A-associated disorder is a rare condition affecting the central nervous system. It displays a wide phenotypic spectrum, ranging from isolated late-onset torsion dystonia to a severe early-onset disease with developmental delay, neurological deficits, and atrophy of the basal ganglia and cerebellum, therefore complicating variant interpretation and phenotype prediction in patients carrying TUBB4A variants. We applied entropy-based normal mode analysis (NMA) to investigate genotype–phenotype correlations in TUBB4A-releated disease and to develop an in-silico approach to assist in variant interpretation and phenotype prediction in this disorder. Variants included in our analysis were those reported prior to the conclusion of data collection for this study in October 2019. All TUBB4A pathogenic missense variants reported in ClinVar and Pubmed, for which associated clinical information was available, and all benign/likely benign TUBB4A missense variants reported in ClinVar, were included in the analysis. Pathogenic variants were divided into five phenotypic subgroups. In-silico point mutagenesis in the wild-type modeled protein structure was performed for each variant. Wild-type and mutated structures were analyzed by coarse-grained NMA to quantify protein stability as entropy difference value (ΔG) for each variant. Pairwise ΔG differences between all variant pairs in each structural cluster were calculated and clustered into dendrograms. Our search yielded 41 TUBB4A pathogenic variants in 126 patients, divided into 11 partially overlapping structural clusters across the TUBB4A protein. ΔG-based cluster analysis of the NMA results revealed a continuum of genotype–phenotype correlation across each structural cluster, as well as in transition areas of partially overlapping structural clusters. Benign/likely benign variants were integrated into the genotype–phenotype continuum as expected and were clearly separated from pathogenic variants. We conclude that our results support the incorporation of the NMA-based approach used in this study in the interpretation of variant pathogenicity and phenotype prediction in TUBB4A-related disease. Moreover, our results suggest that NMA may be of value in variant interpretation in additional monogenic conditions.

Functional analysis of patient-derived PALB2 missense variants of uncertain significance.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 1531-1531
Author(s):  
Shijie Wu ◽  
Jiaojiao Zhou ◽  
Yiding Chen
Keyword(s):  
Breast Cancer ◽  
Functional Analysis ◽  
In Silico ◽  
Cancer Genetic Counseling ◽  
Wild Type ◽  
Variants Of Uncertain Significance ◽  
Missense Variants ◽  
Pathogenic Variants ◽  
Uncertain Significance ◽  
The Impact

1531 Background: Inherited PALB2 pathogenic variants are associated with an increased lifetime risk for breast cancer development. However, the interpretation of numerous PALB2 missense variants of uncertain significance (VUS) identified in germline genetic testing remains a challenge. Here, we assessed the impact of breast cancer patient-derived VUS on PALB2 function and identified pathogenic PALB2 missense variants that may increase cancer risk. Methods: A total of seven potentially pathogenic PALB2 VUS identified in 2,279 breast cancer patients were selected for functional analysis. All these selected VUS were assessed by SIFT, Align-GVGD, and PolyPhen2 in silico and were predicted to be deleterious by at least two in silico algorithms. The p.L35P [c.104T > C] variant was also included, for which pathogenicity has been recently confirmed. The effects of the VUS on the homologous recombination (HR) activity of PALB2 were tested by U2OS/DR-GFP reporting system. Functional characterization was further validated by protein co-immunoprecipitation and RAD51 recruitment assay. Results: PALB2 variants p.L24F [c.72G > C] and p.L35P [c.104T > C] showed the most significant disruption to the HR activity of PALB2 relative to the wild-type condition, retaining only 52.2% ( p = 0.0013) and 8.5% ( p < 0.0001) of HR activity respectively. Moderate but statistically significant HR deficiency was observed for four other variants (p.P405A [c.1213C > G], p.T1012I [c.3035C > T], p.E1018D [c.3054G > C], and p.T1099M [c.3296C > T]). We found no statistical differences for the p.K628N [c.1884G > T] and p.R663C [c.1987C > T] in the HR activity compared to wild-type PALB2. The p.L24F and p.L35P variants compromised the BRCA1-PALB2 interaction and reduced RAD51 foci formation in response to DNA damage. Conclusions: We have identified a novel patient-derived pathogenic PALB2 missense variant, p.L24F [c.72G > C], that compromises PALB2-mediated HR activity. We suggest the integration of the identified pathogenic variants into breast cancer genetic counseling and individualized treatment regimens for better clinical outcomes.

scholarly journals In-silico Analysis of NF1 Missense Variants in ClinVar: Translating Variant Predictions into Variant Interpretation and Classification

2020 ◽  
Vol 21 (3) ◽  
pp. 721 ◽  
Author(s):  
Matteo Accetturo ◽  
Nicola Bartolomeo ◽  
Alessandro Stella
Keyword(s):  
Genetic Diseases ◽  
In Silico Analysis ◽  
Neurofibromatosis Type ◽  
Fine Tuning ◽  
Variant Interpretation ◽  
Score Distribution ◽  
Clinical Criteria ◽  
Missense Variants ◽  
Pathogenic Variants ◽  
Criteria For Diagnosis

Background: With the advent of next-generation sequencing in genetic testing, predicting the pathogenicity of missense variants represents a major challenge potentially leading to misdiagnoses in the clinical setting. In neurofibromatosis type 1 (NF1), where clinical criteria for diagnosis may not be fully present until late infancy, correct assessment of variant pathogenicity is fundamental for appropriate patients’ management. Methods: Here, we analyzed three different computational methods, VEST3, REVEL and ClinPred, and after extracting predictions scores for 1585 NF1 missense variants listed in ClinVar, evaluated their performances and the score distribution throughout the neurofibromin protein. Results: For all the three methods, no significant differences were present between the scores of “likely benign”, “benign”, and “likely pathogenic”, “pathogenic” variants that were consequently collapsed into a single category. The cutoff values for pathogenicity were significantly different for the three methods and among benign and pathogenic variants for all methods. After training five different models with a subset of benign and pathogenic variants, we could reclassify variants in three sharply separated categories. Conclusions: The recently developed metapredictors, which integrate information from multiple components, after gene-specific fine-tuning, could represent useful tools for variant interpretation, particularly in genetic diseases where a clinical diagnosis can be difficult.

scholarly journals KVarPredDB: a database for predicting pathogenicity of missense sequence variants of keratin genes associated with genodermatoses

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Yuyi Ying ◽  
Lu Lu ◽  
Santasree Banerjee ◽  
Lizhen Xu ◽  
Qiang Zhao ◽  
...  
Keyword(s):  
Amino Acids ◽  
Web Application ◽  
Functional Characterization ◽  
Dominant Mode ◽  
Heptad Repeat ◽  
Wild Type ◽  
Application Development ◽  
Missense Variants ◽  
Pathogenic Variants ◽  
Development Framework

Abstract Background Germline variants of ten keratin genes (K1, K2, K5, K6A, K6B, K9, K10, K14, K16, and K17) have been reported for causing different types of genodermatoses with an autosomal dominant mode of inheritance. Among all the variants of these ten keratin genes, most of them are missense variants. Unlike pathogenic and likely pathogenic variants, understanding the clinical importance of novel missense variants or variants of uncertain significance (VUS) is the biggest challenge for clinicians or medical geneticists. Functional characterization is the only way to understand the clinical association of novel missense variants or VUS but it is time consuming, costly, and depends on the availability of patient’s samples. Existing databases report the pathogenic variants of the keratin genes, but never emphasize the systematic effects of these variants on keratin protein structure and genotype-phenotype correlation. Results To address this need, we developed a comprehensive database KVarPredDB, which contains information of all ten keratin genes associated with genodermatoses. We integrated and curated 400 reported pathogenic missense variants as well as 4629 missense VUS. KVarPredDB predicts the pathogenicity of novel missense variants as well as to understand the severity of disease phenotype, based on four criteria; firstly, the difference in physico-chemical properties between the wild type and substituted amino acids; secondly, the loss of inter/intra-chain interactions; thirdly, evolutionary conservation of the wild type amino acids and lastly, the effect of the substituted amino acids in the heptad repeat. Molecular docking simulations based on resolved crystal structures were adopted to predict stability changes and get the binding energy to compare the wild type protein with the mutated one. We use this basic information to determine the structural and functional impact of novel missense variants on the keratin coiled-coil heterodimer. KVarPredDB was built under the integrative web application development framework SSM (SpringBoot, Spring MVC, MyBatis) and implemented in Java, Bootstrap, React-mutation-mapper, MySQL, Tomcat. The website can be accessed through http://bioinfo.zju.edu.cn/KVarPredDB. The genomic variants and analysis results are freely available under the Creative Commons license. Conclusions KVarPredDB provides an intuitive and user-friendly interface with computational analytical investigation for each missense variant of the keratin genes associated with genodermatoses.

scholarly journals A force field for virtual atom molecular mechanics of proteins

2009 ◽  
Vol 106 (37) ◽  
pp. 15667-15672 ◽  
Author(s):  
Anil Korkut ◽  
Wayne A. Hendrickson
Keyword(s):  
Force Field ◽  
Molecular Mechanics ◽  
Normal Mode ◽  
Conformational Changes ◽  
Normal Mode Analysis ◽  
Coarse Grained ◽  
Mode Analysis ◽  
Biological Macromolecules ◽  
Molecular Mechanics Calculations ◽  
Low Degrees

Activities of many biological macromolecules involve large conformational transitions for which crystallography can specify atomic details of alternative end states, but the course of transitions is often beyond the reach of computations based on full-atomic potential functions. We have developed a coarse-grained force field for molecular mechanics calculations based on the virtual interactions of Cα atoms in protein molecules. This force field is parameterized based on the statistical distribution of the energy terms extracted from crystallographic data, and it is formulated to capture features dependent on secondary structure and on residue-specific contact information. The resulting force field is applied to energy minimization and normal mode analysis of several proteins. We find robust convergence in minimizations to low energies and energy gradients with low degrees of structural distortion, and atomic fluctuations calculated from the normal mode analyses correlate well with the experimental B-factors obtained from high-resolution crystal structures. These findings suggest that the virtual atom force field is a suitable tool for various molecular mechanics applications on large macromolecular systems undergoing large conformational changes.

scholarly journals KVarPredDB: A database for predicting pathogenicity of missense sequence variants of keratin genes associated with genodermatoses

2020 ◽  
Author(s):  
Yuyi Ying ◽  
Lu Lu ◽  
Santasree Banerjee ◽  
Lizhen Xu ◽  
Qiang Zhao ◽  
...  
Keyword(s):  
Amino Acids ◽  
Web Application ◽  
Functional Characterization ◽  
Dominant Mode ◽  
Heptad Repeat ◽  
Wild Type ◽  
Application Development ◽  
Missense Variants ◽  
Pathogenic Variants ◽  
Development Framework

Abstract Background: Germline variants of ten keratin genes (K1, K2, K5, K6A, K6B, K9, K10, K14, K16 and K17) have been reported for causing different types of genodermatoses with an autosomal dominant mode of inheritance. Among all the variants of these ten keratin genes, most of them are missense variants. Unlike pathogenic and likely pathogenic variants, understanding the clinical importance of novel missense variants or variants of uncertain significance (VUS) is the biggest challenge for clinicians or medical geneticists. Functional characterization is the only way to understand the clinical association of novel missense variants or VUS but it is time-consuming, costly and depends on the availability of patient’s samples. Existing databases report the pathogenic variants of the keratin genes, but never emphasize the systematic effects of these variants on keratin protein structure and genotype-phenotype correlation.Results: To address this need, we developed a comprehensive database KVarPredDB, which contains information of all ten keratin genes associated with genodermatoses. We integrated and curated 400 reported pathogenic missense variants as well as 4629 missense VUS. KVarPredDB predicts the pathogenicity of novel missense variants as well as to understand the severity of disease phenotype, based on four criteria; firstly, difference in physico-chemical properties between the wild-type and substituted amino acids, secondly, the loss of inter/intra-chain interactions, thirdly, evolutionary conservation of the wild type amino acids and lastly, the effect of the substituted amino acids in the heptad repeat. Molecular docking simulations based on resolved crystal structures were adopted to predict stability changes and get the binding energy to compare the wild type protein with the mutated one. We use this basic information to determine the structural and functional impact of novel missense variants on the keratin coiled-coil heterodimer. KVarPredDB was built under the integrative web application development framework SSM (SpringBoot, Spring MVC, MyBatis) and implemented in Java, Bootstrap, React-mutation-mapper, MySQL, Tomcat. The website can be accessed through http://bioinfo.zju.edu.cn/KVarPredDB. The genomic variants and analysis results are freely available under the Creative Commons license.Conclusions: KVarPredDB provides an intuitive and user-friendly interface with computational analytical investigation for each missense variant of the keratin genes associated with genodermatoses.

scholarly journals KVarPredDB: A Database for Predicting Pathogenicity of Missense Sequence Variants of Keratin Genes Associated With Genodermatoses

2020 ◽  
Author(s):  
Santasree Banerjee ◽  
Yuyi Ying ◽  
Lu Lu ◽  
Lizhen Xu ◽  
Qiang Zhao ◽  
...  
Keyword(s):  
Amino Acids ◽  
Web Application ◽  
Functional Characterization ◽  
Dominant Mode ◽  
Heptad Repeat ◽  
Wild Type ◽  
Application Development ◽  
Missense Variants ◽  
Pathogenic Variants ◽  
Development Framework

Abstract Background: Germline variants of ten keratin genes (K1, K2, K5, K6A, K6B, K9, K10, K14, K16 and K17) have been reported for causing different types of genodermatoses with an autosomal dominant mode of inheritance. Among all the variants of these ten keratin genes, most of them are missense variants. Unlike pathogenic and likely pathogenic variants, understanding the clinical importance of novel missense variants or variants of uncertain significance (VUS) is the biggest challenge for clinicians or medical geneticists. Functional characterization is the only way to understand the clinical association of novel missense variants or VUS but it is time-consuming, costly and depends on the availability of patient’s samples. Existing databases report the pathogenic variants of the keratin genes, but never emphasize the systematic effects of these variants on keratin protein structure and genotype-phenotype correlation. Results: To address this need, we developed a comprehensive database KVarPredDB, which contains information of all ten keratin genes associated with genodermatoses. We integrated and curated 398 reported pathogenic missense variants as well as 4629 missense VUS. KVarPredDB predicts the pathogenicity of novel missense variants as well as to understand the severity of disease phenotype, based on four criteria; firstly, difference in physico-chemical properties between the wild-type and substituted amino acids, secondly, the loss of inter/intra-chain interactions, thirdly, evolutionary conservation of the wild type amino acids and lastly, the effect of the substituted mutation in the heptad repeat. Molecular docking simulations based on resolved crystal structures were adopted to predict stability changes and get the binding energy to compare the wild type protein with the mutated one. We use this basic information to determine the structural and functional impact of novel missense variants on the keratin coiled-coil heterodimer. KVarPredDB was implemented in Java, Bootstrap, React-mutation-mapper, common MySQL, Tomcat, and under the integrative web application development framework SSM (SpringBoot, Spring MVC, MyBatis). The web site can be accessed through http://bioinfo.zju.edu.cn/KVarPredDB. The genomic variants and analysis results are freely available under the Creative Commons license.Conclusions: KVarPredDB provides an intuitive and user-friendly interface with computational analytical investigation for each missense variant of the keratin genes associated with genodermatoses.

A minimal coarse-grained model for the low-frequency normal mode analysis of icosahedral viral capsids

Soft Matter ◽  
2020 ◽  
Vol 16 (14) ◽  
pp. 3443-3455 ◽  
Author(s):  
M. Martín-Bravo ◽  
J. M. Gomez Llorente ◽  
J. Hernández-Rojas
Keyword(s):  
Structural Properties ◽  
Normal Mode ◽  
Normal Mode Analysis ◽  
Low Frequency ◽  
Coarse Grained ◽  
Mode Analysis ◽  
Viral Capsids ◽  
Mode Spectrum ◽  
Coarse Grained Model

A minimal coarse-grained model unveils relevant structural properties of icosahedral viral capsids when fitted to reproduce their low-frequency normal-mode spectrum.

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