GET THE APP

In silico Functional Analysis of Variants in Genes Associated with Sudden Cardiac Death in Cases of the National Institute of Legal Medicine of Colombia
..

Journal of Forensic Research

ISSN: 2157-7145

Open Access

Research - (2023) Volume 14, Issue 3

In silico Functional Analysis of Variants in Genes Associated with Sudden Cardiac Death in Cases of the National Institute of Legal Medicine of Colombia

Joseph Alape Ariza1,2,4*, Andrea Pinzon Reyes2, Arbey Hernan Medina Rocha3, Rodrigo Cabrera Perez4,5 and Clara Isabel Bermudez Santana6,7
*Correspondence: Joseph Alape Ariza, Department of Forensic Sciences Research Group, National Institute of Legal Medicine and Forensic Sciences, Calle 7 A No. 12 A 51, Bogotá, Colombia, Email:
1Department of Forensic Sciences Research Group, National Institute of Legal Medicine and Forensic Sciences, Calle 7 A No. 12 A 51, Bogotá, Colombia
2Forensic Genetics Research Group, National Institute of Legal Medicine and Forensic Sciences, Calle 7 A No. 12 A 51, Bogotá, Colombia
3Department of Forensic Pathology Group, Bogotá Regional Directorate, National Institute of Legal Medicine and Forensic Sciences, Calle 7 A No. 12 A 51, Bogotá, Colombia
4Department of Forensic Pathology, Institute of Cardiology, Fundación Cardio Infantil, Calle 163 A No. 13 B 80, Bogota, Colombia
5Department of Forensic Pathology, Institute of Translational Medicine (IMT), Rosario University, Bogotá, Colombia
6Department of Biology, Research Group in Rnomics, National University of Colombia, Carrerra 45, Bogotá, Colombia
7Center of Excellence in Scientific Computing, National University of Colombia, Bogotá, Colombia

Received: 19-May-2023, Manuscript No. jfr-23-99326; Editor assigned: 22-May-2023, Pre QC No. P-99326; Reviewed: 03-Jun-2023, QC No. Q-99326; Revised: 09-Jun-2023, Manuscript No. R-99326; Published: 16-Jun-2023 , DOI: 10.37421/2157-7145.2023.14.555
Citation: Ariza, Joseph Alape, Andrea Pinzon Reyes, Arbey Hernan Medina Rocha and Rodrigo Cabrera Perez, et al. “In silico Functional Analysis of Variants in Genes Associated with Sudden Cardiac Death in Cases of the National Institute of Legal Medicine of Colombia.” J Forensic Res 14 (2023): 555.
Copyright: © 2023 Ariza JA, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract

Diseases of cardiovascular origin such as cardiomiopathies and canalopatías are the main causes of sudden cardiac death and in some cases are difficult to diagnose during autoposy. We present an in silico analysis using bioinformatic tools, for the analysis of possibly pathogenic variants in genes associated with sudden cardiac death. Algorithms were used to predict pathogenicity, predicting the impact of SNPs on proteins, genomic specificity and protein-protein interaction. We found that variants in the KCNH2, ANK3, TTN, CAV3 and DSP genes cause structural alterations, molecular, cellular and interstitial changes in the heart that can trigger sudden death.

Keywords

NGS • Sudden cardiac death • MutPred2 • ShinyGO • Protein analysis

Introduction

Cardiovascular diseases are one of the leading causes of sudden cardiac death (SCD) [1]. Cardiomyopathies and canalalopathies are the most frequent, with a hereditary component and difficulty in their detection during medico-legal autopsies. Hereditary cardiomyopathies such as hypertrophic cardiomyopathy, dilated cardiomyopathy and arrhythmogenic cardiomyopathy are difficult to diagnose as they present minimal structural changes in the heart [2,3]. Channelopathies are not associated with anatomical changes, but affect heart rhythm and cardiac electrical conduction triggering sudden cardiac arrest, which also hinder their postmortem diagnosis [2-4].

In recent years with the development of massive parallel sequencing or next-generation sequencing (NGS), which allows sequencing the genome and the complete exome of a patient, to analyze the totality of the genes of an individual. This methodology has made it possible to identify a large number of genetic variants. However, the validation of all of them through electrophysiological functional studies can be costly and time-consuming. One possible strategy to overcome this challenge is to evaluate each potentially pathogenic variant using the bioinformatics approach [5,6].

Different prediction algorithms and statistical models have been developed to explore the association between genetic variants and diseases, considering protein stability, sequence conservation, physical and chemical properties and structural variations [7,8]. Structural analysis helps to develop hypotheses about the possible impacts of substitutions and their possible links to disease states. Amino acid changes can affect both the normal function of a protein by changing the hydrogen bond network, pH dependence, disturbing ligand binding and conformational dynamics, transductional modification [9,10].

Different studies have considered structural variations of proteins and free energy changes when evaluating deregulatory effects [11-13], which have demonstrated the effectiveness of predicting the possible influence of amino acid changes on proteins [14].

Considering a group of genes from an NGS study of cases of indeterminate deaths, possibly pathogenic variants were recovered and using structural and functional analysis in silico aimed to describe possibly pathogenic variants associated with sudden cardiac death, to improve predictions of pathogenicity.

Methodology

We selected 68 cases of deaths to be determined, without macro and microscopic lesions during autopsy, with negative toxicology and virology. Whole blood DNA extraction was performed using the QIAamp®DNA Blood Midi/Maxi kit, following the manufacturer's recommendations. The quantification of DNA and libraries was performed using the Quantitating dsDNA kit using the Quantus™ Fluorometer instrument and following the manufacturer's recommendations. 2 × 150 bp paired-end NGS sequencing with MiSeq equipment (Illumina Inc., San Diego, CA. USA) using MiSeq Reagent V3 (150 clycles), according to the protocol of the commercial house.

Data analysis

The alinators Bowtie2, BWA-MEM and NovoAlign was aligned to the reference human genome sequence (GRCh37) were used, to identify the variaantes genomic analysis tools HaplotypeCaller (GATK-HC), Samtools mpileup and Freebayes were used. The variants were annotated by SnpEff and ANNOVAR, including predictive algorithms in silico SIFT, PolyPhen-2, MutationTaster, LRT, Mutation Assesor, FATHMM (Functional Analysis through Hidden Markov Models), MetaSVM, RadialSVM, LR, CADD, GERP++, phyloP and SiPhy, to evaluate pathogenicity. Variant filtering by determining minor allele frequency (MAF) and selecting variants for in silico analysis was performed considering the recommendations of the American College of Medical Genetics and Genomics (ACMG) [15-18].

Predicting SNP impact on protein stability

MutPred2: Machine learning-based method that integrates genetic and molecular data to probabilistically infer the pathogenicity of amino acid substitutions and their molecular mechanisms, by general pathogenicity prediction and a ranked list of specific molecular alterations that may affect the phenotype [19].

Genomic specificity analysis by ShinyGO

ShinyGO analyzes the genomic specificity of genes compared to the whole genome. Four aspects are compared: number of exons, number of transcription isoforms per gene, genome extension and length of 3′-UTR (untranslated region) [20]. Novel features of ShinyGO include graphical display of enrichment results and gene characteristics and access to the application program interface (API) to KEGG and STRING for retrieval of pathway diagrams and protein-protein interaction networks. ShinyGO is a graphical and intuitive web application that can help researchers gain actionable insights from gene lists. Availability: http://ge-lab.org/go/. Gene Ontology (GO) is a unique database that describes the characteristics and cellular localization of each gene [21]. KEGG is a database containing a large number of known metabolic pathways of genes [22].

Analysis of protein-protein interaction and functional networks

Additionally, an analysis of protein-protein interaction and functional networks was performed to investigate the direct physical and functional relationships between identified genes, with the database (STRING) (http:// string.embl.de) [23]. The STRING database provided a score for each genegene interaction, calculated as the joint probability of the probabilities of the different evidence channels (protein interaction, fusion, co-expression, etc.), an approximate functional network was constructed on the basis of the expression profile of the proteins identified in the present study.

Results and Discussion

With the pathogenicity prediction algorithms of the 72 variants detected, in 41.66% it was not possible to obtain pathogenicity prediction results by any of the prediction algorithms used. Analysis with SIFT (26) variants was found to be harmful; with Polyphen2 (28) harmful and (8) probably harmful; for Mutation Taster (28) harmful. With reference to the other prediction algorithms there is a discrepancy in the prediction of pathogenicity. For sequence conservation prediction algorithms, it was found that for GEPP++RS with cut-off point greater than 4.4, it was found that in 14 of the variants there is no sequence conservation, for CADD with a cut-off point of 20, 12 harmful variants were found.

Relevant protein variants that had a defined crystallography structure were selected for further in silico studies that would allow us to understand the molecular mechanism and better classify whether the variant may actually become pathogenic.

Predicting the impact of SNPs on protein stability

Protein stability prediction analysis with MUPred2: MutPred2, allows to know molecular mechanisms that can be altered by a variant in a protein (Table 1). Cardiovascular remodeling is defined as a set of molecular, cellular and interstitial changes that occur in the heart and vessels due to different injuries. Changes in size, geometry and function are the key events that occur in the heart. Pathophysiology includes cell death, changes in energy metabolism, inflammation, oxidative stress, alteration in the extracellular matrix, neurohormonal activation and changes in ion transport [24].

Table 1: Prediction of protein stability with MutPred2 for variants of KCNH2, ANK3, TTN, CTDSP2, CAV3 and DSP genes.

ID Substitution MutPred2 score Molecular Mechanisms with P-values <= 0.05 Probability P-value Affected PROSITE and ELM Motifs
NP_742053.1_KCNH2 R92P 0.812 Loss of Helix 0.30 5.3e-03 ELME000002, ELME000102,
ELME000233, PS00007
Gain of Strand 0.30 2.7E-03
Loss of SUMOylation at K93 0.21 0.03
ANK3 P1489S 0.594 Altered Ordered interface 0.25 0.02 ELME000052, ELME000053,
ELME000063, ELME000106,
ELME000173, ELME000336
Gain of O-linked glycosylation at T1491 0.24 9.6E-03
Altered Transmembrane protein 0.15 0.01
Gain of Proteolytic cleavage at R1486 0.14 0.02
Loss of Sulfation at Y1494 0.01 0.05
TTN P16475Q 0.755 Altered Transmembrane protein 0.30 1.4e-04 ELME000052, ELME000062,
ELME000117, ELME000136,
ELME000159, ELME000202
Altered Ordered interface 0.28 0.04
Gain of Strand 0.26 0.04
Loss of ADP-ribosylation at R16472 0.23 0.02
TTN P1698L 0.845 Altered Transmembrane protein 0.20 5.5E-03 None
Altered Metal binding 0.19 0.02
TTN P16475Q 0.755 Altered Stability 0.28 6.6e-03 ELME000052, ELME000063,
ELME000070, ELME000182, PS00001
Altered Transmembrane protein 0.16 0.01
Loss of Disulfide linkage at C24664 0.12 0.04
Gain of N-linked glycosylation at N24658 0.06 0.02
TTN P1698L 0.845 Altered Transmembrane protein 0.20 5.5E-03 None
Altered Metal binding 0.19 0.02
TTN I24660T 0.707 Altered Stability 0.28 6.6e-03 ELME000052, ELME000063,
ELME000070, ELME000182, PS00001
Altered Transmembrane protein 0.16 0.01
Loss of Disulfide linkage at C24664 0.12 0.04
Gain of N-linked glycosylation at N24658 0.06 0.02
TTN P22367L 0.723 Gain of Phosphorylation at Y22368 0.26 0.03 ELME000080
CTDSP2 I106T 0.823 Altered Stability 0.63 8.1e-04 ELME000220, ELME000333, PS00006
Altered Metal binding 0.29 3.4e-03
Loss of Catalytic site at E110 0.19 0.01
CAV3 Y62C 0.702 Altered Ordered interface 0.35 2.5E-03 ELME000052, ELME000053,
ELME000063, ELME000080,
ELME000120, ELME000182
Gain of Helix 0.28 0.02
Altered Transmembrane protein 0.20 5.3e-03
DSP N4K 0.586 Altered Ordered interface 0.16 0.05 ELME000285, PS00005
Loss of N-terminal acetylation of M1 0.02 6.2e-03

Since the heart undergoes different physiological stimuli, its pathological adaptation can lead to cardiomyopathies, cardiac dysfunction and ultimately heart failure [25,26]. SUMOylation modifies protein-protein interactions, enzyme activity, or chromatin binding in a multitude of key cellular processes, acting as a highly dynamic molecular switch [27-29]. In the present study was found loss of SUMOilación in the protein gene KCNH2, which suggests that this protein, along with loss of the helix and gain in the strand lose its functional stability having a high probability of incidence in the presence of LQTS2.

Mutations in the KCNH2 gene cause LQTS2, is the second most common cause of congenital LQTS and responsible for 35% to 45% of all genotyped LQTS [30] and that 25% of cases of LQTS are not diagnosed, which makes identification in family groups difficult and the determinants of variability in disease severity are still largely unknown, because some members despite having the mutation are asymptomatic [31].

In the heart, O-linked glycosylation is recognized as an important mechanism involved in the regulation of many cellular processes, including cellular metabolism, mitochondrial function, quality control and protein turnover, autophagy and calcium management [13-32]. Glycation can alter the function and stability of proteins and induce the synthesis of pathogenic molecules that favor the appearance and progression of different diseases, including cardiovascular diseases [33,34].

In the present study it was found that the variant in the ANK3 protein produces an O-linked glycosylation gain, alters the transmembrane protein, produces loss of sulfation in tyrosine and alters the interphase order, which has a high probability of having harmful effects on the regulation of the heart.

The role of O-linked glycosylation in the regulation of cardiovascular function is complex and that, like most studies, focuses on its role in cardiovascular pathophysiology. On the other hand, as we begin to understand more about the cellular functions regulated by O-linked glycosylation protein, it is becoming increasingly clear that a more accurate concept would be that O-linked glycosylation modification of cardiovascular proteins is a dynamic process that is critical to maintaining normal cardiomyocyte function [35,36]. Likewise, in the TTN, CDSP2 and CAV3 proteins, it is also established loss and or changes of the molecular mechanisms, which practically remodel the functioning of the heart, which implies that these variants cause loss in the stability of the protein, which can be the cause of the presence of arrhythmogenic diseases.

N-terminal acetylation is a post-translational modification carried out by N-terminal acetyltransferases (NAT) in nascent protein chains during translation, involved in the maturation of post-translational proteins, physicochemically affecting the N-terminal limb of most proteins [37]. The loss of N-terminal acetylation and its previously unanticipated role in protein biogenesis, globally remodels the proteome to create a unique phenotype [38]. Therefore, pathogenic variants in DSP with loss of NAT could lead to abnormal contractile function of cardiac cells, additional because this protein is responsible for binding the cardiac desmosome with intermediate filaments. Alterations in this biosynthesis could trigger arrhythmogenic cardiomyopathy that is estimated to affect 0.02% to 0.1% of the population with an increased risk of sudden cardiac death and heart failure [39,40].

GO enrichment analysis

Analysis of GO enrichment of AKAP9, ANK2, ANK3, ANKRD1, CACNA1C, CACNB2, CASQ2, CAV3, CTNNA3, DSG2, DSP, KCND3, KCNE3, KCNH2, KCNJ5, KCNQ1, MYBPC3, NOS1AP, PRDM16, RYR2, SCN10A, SCN4B, SCN5A, SLMAP, SNTA1, TMEM43, TNNT2, TPM1, TRDN, TRPMP4 and TTN, using ShinyGO.

It has been reported that the higher the hierarchical level of GO terms in the tree structure, the more explicit the demonstrated biological function (Jain S, Bader GD.2010). Therefore, only bio-enriched GO terms with a false discovery rate (FDR) value less than 0.05 remained as remarkably enriched terms. Pathways with an FDR value less than 0.05 and containing at least 5 genes were considered significantly enriched.

The pathways with greater biological enrichment highlighted in Table 2, nine pathways were found related to cardiac conduction, action potential and membrane repolarization, caused by defects in the genes encoding ion channels such as potassium, sodium and calcium or associated proteins that alter the generation and transmission of the action potential that predispose to fatal arrhythmias and sudden cardiac death, such as the DSG2, KCNH2, DSP, KCNJ5, AKAP9, ANK2, CACNB2, KCND3, KCNE3, SCN4B, CTNNA3 and SCN5A genes involved in cardiac channelopathies [41,42] (Table 2).

Table 2: ShinyGO biological enrichment.

Enrichment FDR nGenes Pathway Genes Fold Enrichment Pathway Genes
1256,943587 5 11 3.70065E+14 AV node cell action potential CACNB2 SCN4B SCN5A SCN10A RYR2
1256,943587 5 11 3.70065E+14 AV node cell to bundle of His cell signaling CACNB2 SCN4B SCN5A SCN10A RYR2
2.04292E-13 11 25 3.58223E+14 Ventricular cardiac muscle cell membrane repolarization KCNH2 SNTA1 KCNJ5 AKAP9 ANK2 KCND3 KCNE3 SCN4B CAV3 SCN5A NOS1AP
1.5183E-06 9 21 3.48918E+14 Reg. of ventricular cardiac muscle cell membrane repolarization KCNH2 SNTA1 AKAP9 ANK2 KCNE3 SCN4B CAV3 SCN5A NOS1AP
2.83816E-15 13 34 3.1129E+14 Ventricular cardiac muscle cell action potential DSG2 KCNH2 DSP SNTA1 KCNJ5 ANK2 KCND3 KCNE3 CAV3 CTNNA3 SCN5A RYR2 NOS1AP
4969,229302 5 14 2.90765E+14 Membrane repolarization during ventricular cardiac muscle cell action potential KCNH2 KCNJ5 KCND3 KCNE3 NOS1AP
7357,844876 5 15 2.71381E+14 Bundle of His cell to Purkinje myocyte communication DSG2 DSP CTNNA3 SCN5A SCN10A
0,612051969 7 22 2.59045E+14 Membrane depolarization during cardiac muscle cell action potential ANK2 ANK3 SLMAP CACNB2 SCN4B CAV3 SCN5A
131619,8334 4 13 2.50505E+14 Reg. of ventricular cardiac muscle cell action potential DSG2 DSP CTNNA3 RYR2
0,008218532 8 27 2.41228E+14 Reg. of cardiac muscle cell action potential DSG2 DSP AKAP9 ANK2 CAV3 CTNNA3 RYR2 NOS1AP
5.78813E-07 10 34 2.39454E+14 Reg. of membrane repolarization KCNH2 SNTA1 CASQ2 AKAP9 ANK2 KCNE3 SCN4B CAV3 SCN5A NOS1AP
2.56466E-11 12 41 2.38286E+14 Reg. of heart rate by cardiac conduction DSG2 KCNH2 DSP KCNJ5 AKAP9 ANK2 CACNB2 KCND3 KCNE3 SCN4B CTNNA3 SCN5A
6.60817E-18 15 52 2.34849E+14 Cardiac muscle cell action potential involved in contraction DSG2 KCNH2 DSP SNTA1 KCNJ5 ANK2 CACNB2 KCND3 KCNE3 SCN4B CAV3 CTNNA3 SCN5A RYR2 NOS1AP
190236387,4 3 11 2.22039E+14 SA node cell to atrial cardiac muscle cell communication ANK2 SCN5A RYR2
8.94148E-11 12 45 2.17105E+14 Membrane repolarization KCNH2 SNTA1 CASQ2 KCNJ5 AKAP9 ANK2 KCND3 KCNE3 SCN4B CAV3 SCN5A NOS1AP
26186,2998 5 19 2.14248E+14 Atrial cardiac muscle cell action potential KCNJ5 ANK2 CACNB2 SCN5A RYR2
26186,2998 5 19 2.14248E+14 Atrial cardiac muscle cell to AV node cell signaling KCNJ5 ANK2 CACNB2 SCN5A RYR2
1.45932E-25 19 74 2.09037E+13 Cardiac muscle cell action potential DSG2 KCNH2 DSP SNTA1 KCNJ5 AKAP9 ANK2 ANK3 SLMAP CACNB2 KCND3 KCNE3 SCN4B CAV3 CTNNA3 SCN5A SCN10A RYR2 NOS1AP
2.54198E-07 10 39 2.08755E+14 Reg. of actin filament-based movement DSG2 DSP TNNT2 AKAP9 MYBPC3 ANK2 CAV3 CTNNA3 SCN5A RYR2
3.54913E-05 9 36 2.03536E+14 Membrane depolarization during action potential KCNH2 ANK2 ANK3 SLMAP CACNB2 SCN4B CAV3 SCN5A SCN10A

In Table 3 molecular enrichment, genes are involved in the formation and regulation of different voltage-dependent ion channels, so any alteration in any of the pathways in which they interact will be pathogenic (Table 3).

Table 3: ShinyGO molecular enrichment.

Enrichment FDR nGenes Pathway Genes Fold Enrichment Pathway Genes
2595314,67 4 12 2.71381E+14 Voltage-gated potassium channel activity involved in ventricular cardiac muscle KCNH2 KCNJ5 KCND3 KCNE3
3914323,131 4 15 2.17105E+14 Nitric-oxide synthase binding SNTA1 CAV3 SCN5A NOS1AP
3.63898E+13 2 11 1.48026E+14 Protein binding involved in heterotypic cell-cell adhesion DSG2 DSP
5.02076E+13 2 13 1.25253E+14 Titin binding MYBPC3 ANKRD1
2611015095 3 24 1.01768E+14 Voltage-gated sodium channel activity SCN4B SCN5A SCN10A
1.30897E+14 2 22 7.4013E+13 Inward rectifier potassium channel activity KCNH2 KCNJ5
1.30897E+14 2 22 7.4013E+13 Cytoskeletal anchor activity ANK2 ANK3
2.92133E+14 1 11 7.4013E+13 High voltage-gated calcium channel activity CACNB2
2.92133E+14 1 11 7.4013E+13 Structural molecule activity conferring elasticity TTN
0,000865976 12 140 6.97837E+14 Transmembrane transporter binding SNTA1 AKAP9 ANK2 ANK3 KCND3 KCNE3 SCN4B CAV3 SCN5A SCN10A TRDN RYR2
8709309595 3 38 6.42744E+14 Sodium channel regulator activity SNTA1 SCN4B CAV3
1.71884E+14 2 26 6.26264E+14 Protein kinase A regulatory subunit binding AKAP9 RYR2
3.36429E+14 1 13 6.26264E+14 Outward rectifier potassium channel activity KCND3
1.95452E+14 2 28 5.81531E+14 Spectrin binding ANK2 ANK3
3.49314E+14 1 14 5.81531E+14 Myosin heavy chain binding MYBPC3
3.49314E+14 1 14 5.81531E+14 Protein kinase A catalytic subunit binding RYR2
3.49314E+14 1 14 5.81531E+14 C3HC4-type RING finger domain binding KCNH2
3.65446E+14 1 15 5.42762E+14 Histone methyltransferase activity (H3-K9 specific) PRDM16
3.65446E+14 1 15 5.42762E+14 Muscle alpha-actinin binding TTN
1.2821E+13 3 46 5.30963E+14 Sodium channel activity SCN4B SCN5A SCN10A

In Figure 1, using the chi-square test, the number of exons showed a p-value (0.0023) when comparing SDRs with other genes in the genome. In addition, the number of transcription isoforms per gene were significantly different from the expected value with a value of p=0.051. These results indicated that our identified SDRs may have strong transcription characteristics with other genes, which may be involved in heart disease. For genome extension analysis, we observed an extremely low p-value (0.00096), while for the 3′-UTR length comparison, we observed a p-value (0.52) and for 5'-UTR p (0.76). There is a strong association between these genes and therefore the presence of possibly pathogenic variants present an increased risk of death due to cardiac arrhythmias, cardiomyopathies and coronary heart disease. For example, about 50% of ARVC cases are associated with mutations in genes encoding desmosome and cell adhesion proteins necessary for mechano-electrical coupling in the heart [43].

forensic-research-characteristics

Figure 1. Comparison of AKAP9, ANK2, ANK3, ANKRD1, CACNA1C, CACNB2, CASQ2, CAV3, CTNNA3, DSG2, DSP, KCND3, KCNE3, KCNH2, KCNJ5, KCNQ1, MYBPC3, NOS1AP, PRDM16, RYR2, SCN10A, SCN4B, SCN5A, SLMAP, SNTA1, TMEM43, TNNT2, TPM1, TRDN, TRPMP4 and TTN genes with the rest of the genes in the genome. Chisquare and Student's t tests were run to see if the genes have special characteristics compared to all other genes: (a) Distribution of UTR lengths and (b) Distribution of the genes studied, compared to the genome.

In Figure 2, you can see the great correlation that exists between the genes studied, that all of them are not only interacting, but participate in many of the biological processes that have to do with the heart. It has been previously reported that the higher the hierarchical level of GO terms in the tree structure, the more explicit the biological function [44]. The networks for the biological, cellular and molecular components were constructed Figure 3. The strong interaction between the genes in each of the components is observed.

forensic-research-biological-processes

Figure 2.Enrichment of biological processes in terms of GO for AKAP9, ANK2, ANK3, ANKRD1, CACNA1C, CACNB2, CASQ2, CAV3, CTNNA3, DSG2, DSP, KCND3, KCNE3, KCNH2, KCNJ5, KCNQ1, MYBPC3, NOS1AP, PRDM16, RYR2, SCN10A, SCN4B, SCN5A, SLMAP, SNTA1, TMEM43, TNNT2, TPM1, TRDN, TRPMP4 and TTN (p ≤ 0.05), (a) The color gradient represents the adjusted values and the differences in the size of the bubbles correlate with the enrichment factor and (b) Hierarchical clustering tree, related GO terms are grouped according to the number of genes they share. Larger dots indicate more significant p-values.

forensic-research-networks

Figure 3. Interaction networks of AKAP9, ANK2, ANK3, ANKRD1, CACNA1C, CACNB2, CASQ2, CAV3, CTNNA3, DSG2, DSP, KCND3, KCNE3, KCNH2, KCNJ5, KCNQ1, MYBPC3, NOS1AP, PRDM16, RYR2, SCN10A, SCN4B, SCN5A, SLMAP, SNTA1, TMEM43, TNNT2, TPM1, TRDN, TRPMP4 and TTN.

For the cellular component it is observed that there are two clusters of interaction, one corresponding to the cellular processes of contact between sarcolemma, contraction fibers, it could be said that everything that has with the mechanism of cellular interaction at the physical level and in the other cluster the genes that have to do with transport through ion channels and their associated proteins. In the molecular component (c), it is observed in a large cluster where all interactions are included at the level ce ion channels during the action potential.

KEGG path maps are molecular interaction/reaction network diagrams represented in terms of the KEGG orthology groups, (Figure 4). It shows the enriched pathway diagrams and how the genes studied are interacting with the other molecules Therefore, any variant in genes can cause the presence of the same or different phenotype.

forensic-research-cardiomyopathy

Figure 4. Significant KEGG pathway for (a) Arrhythmogenic right ventricular cardiomyopathy (ARVC), (b) Dilated cardiomyopathy (DM), (c) Hypertrophic cardiomyopathy (HCM) and (d) Cardiac muscle contraction. The genes of interest are highlighted in red.

In this study, it was found enriched ARVC, presents several signaling pathways that are involved in metabolism and cellular behavior presented an enrichment, including calcium signaling pathway, oxytocin signaling pathway, cyclic GMP signaling pathway (cGMP)-protein kinase G (pkg), cyclic AMP (cAMP) signaling pathway, HIF-1 (hypoxic stress response) signaling pathway, mitogen-activated protein kinase (MAPK) signaling pathway, which is consistent with previous studies suggesting that these pathways have important roles in SCD [45,46].

Protein-protein interaction analysis

The STRING functional networks of the proteins TRDN, TTN, CAV3, DSP, DSG2, TRPM4, AKAP9, ANK3, ANK2, CACNA1C, MYBPC3, KCND3 and KCNH2, resulted in a functional network. What their proteins have more interactions with each other than would be expected from a random set of proteins of the same size and degree of distribution extracted from the genome. Such enrichment indicates that the proteins are at least partially biologically connected, as a group in Figure 5.

forensic-research-clusters

Figure 5. Functional network of TRDN, TTN, CAV3, DSP, DSG2, TRPM4, AKAP9, ANK3, ANK2, CACNA1C, MYBPC3, KCND3 and KCNH2 genes with three clusters: cluster 1 (red), cluster 2 (green) and cluster 3 (blue).

The network of these genes when grouped in this way indicates that their proteins have more interactions with each other than would be expected for a random set of proteins of the same size and grade distribution extracted from the genome. Such enrichment indicates that the proteins are at least partially biologically connected, as a group.

Conclusion

Both pathogenicity prediction analysis and biological function enrichment analysis allow us to determine that the variants of the group of genes analyzed participate in several biological processes and that the dysfunction of these genes can lead to the appearance of cardiovascular diseases that can lead to sudden cardiac death. It is of utmost importance when pathogenic variants are present, probably pathogenic and of uncertain significance, to use in silico functional analyzes, to have a broader vision that allows a more accurate diagnosis, given the genetic heterogeneity and phenotypic variability that occurs in this type of diseases. The analysis of cosegregation with relatives in cases of sudden death, is very difficult, this gap can be filled with functional analysis in silico, pathogenicity prediction analysis, GO enrichment analysis and the construction of protein-protein interaction networks, since these allow to understand not only the contribution of genetic factors, but also the molecular mechanisms underlying sudden cardiac death.

Limitations of the Study

The inability to functionally test all candidate variants, with cosegregation studies with relatives, to corroborate the pathogenicity results performed in silico.

Ethical Considerations

In this doctoral thesis, it is the first research carried out in the country and that involved the use of postmortem samples for molecular analysis. The research required the use of bodily fluids which means that informed consent had to be given by family members, this was supplied first, through the approval of the ethics committee of the Faculty of Sciences of the National University of Colombia and secondly through Decree 0786 of 1990, with special emphasis on Chapter VI. Of the Viscerotomies and articles 18, 19 and 20.

Conflict of Interest

The authors state no conflict of interest.

References

  1. Adabag, A. Selcuk, Russell V. Luepker, Véronique L. Roger and Bernard J. Gersh. "Sudden cardiac death: Epidemiology and risk factors."Nat Rev Cardiol 7 (2010): 216-225.
  2. Google Scholar, Crossref, Indexed at

  3. Chugh, Sumeet S., Kyndaron Reinier, Carmen Teodorescu and Audrey Evanado, et al."Epidemiology of sudden cardiac death: Clinical and research implications." Prog Cardiovasc Dis 51 (2008): 213-228.
  4. Google Scholar, Crossref, Indexed at

  5. Kaltman, Jonathan R., Paul D. Thompson, John Lantos and Charles I. Berul, et al. "Screening for sudden cardiac death in the young: Report from a national heart, lung, and blood institute working group."Circ 123 (2011):1911-1918.
  6. Google Scholar, Crossref, Indexed at

  7. Tester, David J., Argelia Medeiros-Domingo, Melissa L. Will and Carla M. Haglund, et al. "Cardiac channel molecular autopsy: Insights from 173 consecutive cases of autopsy-negative sudden unexplained death referred for postmortem genetic testing."Mayo Clin Proc 87 (2012.) 524-539.
  8. Google Scholar, Crossref, Indexed at

  9. Wei, Qiong, Liqun Wang, Qiang Wang and Warren D. Kruger, et al. "Testing computational prediction of missense mutation phenotypes: Functional characterization of 204 mutations of human cystathionine beta synthase." Proteins Struct Funct Bioinform 78 (2010): 2058-2074.
  10. Google Scholar, Crossref, Indexed at

  11. Lincoln, Stephen E., Tina Hambuch, Justin M. Zook and Sara L. Bristow, et al. "One in seven pathogenic variants can be challenging to detect by NGS: An analysis of 450,000 patients with implications for clinical sensitivity and genetic test implementation." Genet Med 23 (2021): 1673-1680.
  12. Google Scholar, Crossref, Indexed at

  13. Schwartz, Charles E., and Chin-Fu Chen. "Progress in detecting genetic alterations and their association with human disease." J Mol Biol 425 (2013): 3914-3918.
  14. Google Scholar, Crossref, Indexed at

  15. Ali, Muhammad Zeeshan, Arshad Farid, Safeer Ahmad and Muhammad Muzammal, et al. "In silico analysis identified putative pathogenic missense nsSNPs in human SLITRK1 gene." Genes 13 (2022): 672.
  16. Google Scholar, Crossref, Indexed at

  17. Stefl, Shannon, Hafumi Nishi, Marharyta Petukh and Anna R. Panchenko, et al. "Molecular mechanisms of disease-causing missense mutations." J Mol Biol 425 (2013): 3919-3936.
  18. Google Scholar, Crossref, Indexed at

  19. Vymětal, Jiří, Kateřina Mertová, Kristýna Boušová and Josef Šulc,et al. "Fusion of two unrelated protein domains in a chimera protein and its 3D prediction: Justification of the x‐ray reference structures as a prediction benchmark." Proteins Struct Funct Bioinform 90 (2022): 2067-2079.
  20. Google Scholar, Crossref, Indexed at

  21. Zhang, Zhe, Shaolei Teng, Liangjiang Wang and Charles E. Schwartz,et al. "Computational analysis of missense mutations causing snyder‐robinson syndrome." Hum Mutat 31 (2010): 1043-1049.
  22. Google Scholar, Crossref, Indexed at

  23. Zhang, Zhe, Joy Norris, Vera Kalscheuer and Tim Wood, et al. "A Y328C missense mutation in spermine synthase causes a mild form of snyder–robinson syndrome." Hum Mol Genet 22 (2013): 3789-3797.
  24. Google Scholar, Crossref, Indexed at

  25. Boccuto, Luigi, Kazuhiro Aoki, Heather Flanagan-Steet and Chin-Fu Chen, et al. "A mutation in a ganglioside biosynthetic enzyme, ST3GAL5, results in salt & pepper syndrome, a neurocutaneous disorder with altered glycolipid and glycoprotein glycosylation." Hum Mol Genet 23 (2014): 418-433.
  26. Google Scholar, Crossref, Indexed at

  27. Ahsan, Tamim, and Abu Ashfaqur Sajib. "Missense variants in the TNFA epitopes and their effects on interaction with therapeutic antibodies—in silico analysis." J Genet Eng Biotechnol 20 (2022): 1-14.
  28. Google Scholar, Crossref, Indexed at

  29. Siepel, Adam, Katherine S. Pollard and David Haussler. "New methods for detecting lineage-specific selection." Int’l Conf in Comput Mol Biol (2006): 190-205.
  30. Google Scholar, Crossref, Indexed at

  31. Garber, Manuel, Mitchell Guttman, Michele Clamp and Michael C. Zody, et al. "Identifying novel constrained elements by exploiting biased substitution patterns." Bioinform 25 (2009): i54-i62.
  32. Google Scholar, Crossref, Indexed at

  33. Richards, Sue, Nazneen Aziz, Sherri Bale and David Bick, et al. "ACMG laboratory quality assurance committee standards and guidelines for the interpretation of sequence variants: A joint consensus recommendation of the american college of medical genetics and genomics and the association for molecular pathology." Genet Med 17 (2015): 405-424.
  34. Google Scholar, Crossref, Indexed at

  35. Li, Quan, and Kai Wang. "InterVar: Clinical interpretation of genetic variants by the 2015 ACMG-AMP guidelines." Am J Hum Genet 100 (2017): 267-280.
  36. Google Scholar, Crossref, Indexed at

  37. Pejaver, Vikas, Jorge Urresti, Jose Lugo-Martinez and Kymberleigh A. Pagel, et al. "Inferring the molecular and phenotypic impact of amino acid variants with MutPred2." Nat Commun 11 (2020): 5918.
  38. Google Scholar, Crossref, Indexed at

  39. Ge, Steven Xijin, Dongmin Jung and Runan Yao. "ShinyGO: A graphical gene-set enrichment tool for animals and plants." Bioinform 36 (2020): 2628-2629.
  40. Google Scholar, Crossref, Indexed at

  41. Ashburner, Michael, Catherine A. Ball, Judith A. Blake and David Botstein, et al. "Gene ontology: Tool for the unification of biology." Nat Genet 25 (2000): 25-29.
  42. Google Scholar, Crossref, Indexed at

  43. Kanehisa, Minoru, Miho Furumichi, Mao Tanabe and Yoko Sato, et al. "KEGG: New perspectives on genomes, pathways, diseases and drugs." Nucleic Acids Res 45 (2017): D353-D361.
  44. Google Scholar, Crossref, Indexed at

  45. Von Mering, Christian, Lars J. Jensen, Berend Snel and Sean D. Hooper, et al. "STRING: Known and predicted protein–protein associations, integrated and transferred across organisms." Nucleic Acids Res 33 (2005): D433-D437.
  46. Google Scholar, Crossref, Indexed at

  47. Azevedo, Paula S, Bertha F. Polegato, Marcos F. Minicucci and Sergio AR Paiva, et al. "Cardiac remodeling: Concepts, clinical impact, pathophysiological mechanisms and pharmacologic treatment." Arq Bras Cardiol 106 (2015): 62-69.
  48. Google Scholar, Crossref, Indexed at

  49. Oldfield, Christopher J., Todd A. Duhamel and Naranjan S. Dhalla. "Mechanisms for the transition from physiological to pathological cardiac hypertrophy." Can J Physiol Pharmacol 98 (2020): 74-84.
  50. Google Scholar, Crossref, Indexed at

  51. He, Xin, Tailai Du, Tianxin Long and Xinxue Liao, et al. "Signaling cascades in the failing heart and emerging therapeutic strategies." Curr Signal Transduct Ther 7 (2022): 134.
  52. Google Scholar, Crossref, Indexed at

  53. Heusch, Gerd. "Myocardial ischaemia–reperfusion injury and cardioprotection in perspective."Nat Rev Cardiol 17 (2020): 773-789.
  54. Google Scholar, Crossref, Indexed at

  55. Chen, Yijin, Tong Xu, Mengsha Li and Chuling Li, et al. "Inhibition of SENP2-mediated Akt deSUMOylation promotes cardiac regeneration via activating Akt pathway."Clin Sci 135 (2021): 811-828.
  56. Google Scholar, Crossref, Indexed at

  57. Cai, Zhaohua, Zi Wang, Ruosen Yuan and Mingli Cui, et al. "Redox-sensitive enzyme SENP3 mediates vascular remodeling via de-SUMOylation of β-catenin and regulation of its stability."EBioMedicine67 (2021): 103386.
  58. Google Scholar, Crossref, Indexed at

  59. Duncan, Gary, Karl Firth, Vinoj George and Minh Duc, et al. "Drug-mediated shortening of action potentials in LQTS2 human induced pluripotent stem cell-derived cardiomyocytes."Stem Cells Dev 26 (2017): 1695-1705.
  60. Google Scholar, Crossref, Indexed at

  61. Wilde, Arthur AM, Ahmad S. Amin and Pieter G. Postema. "Diagnosis, management and therapeutic strategies for congenital long QT syndrome."Heart108 (2022): 332-338.
  62. Google Scholar, Crossref, Indexed at

  63. Erickson, Jeffrey R, Laetitia Pereira, Lianguo Wang and Guanghui Han, et al. "Diabetic hyperglycaemia activates CaMKII and arrhythmias by O-linked glycosylation."Nature502 (2013): 372-376.
  64. Google Scholar, Crossref, Indexed at

  65. Cho, S-J, G. Roman, F. Yeboah and Y. Konishi. "The road to advanced glycation end products: A mechanistic perspective."Curr Med Chem 14 (2007): 1653-167.
  66. Google Scholar, Crossref, Indexed at

  67. Dozio, Elena, Nicola Di Gaetano, Peter Findeise and Massimiliano Marco Corsi Romanelli. "Glycated albumin: From biochemistry and laboratory medicine to clinical practice."Endocrine55 (2017): 682-690.
  68. Google Scholar, Crossref, Indexed at

  69. Wende, Adam R. "Post‐translational modifications of the cardiac proteome in diabetes and heart failure."Proteomics Clin App 10 (2016): 25-38.
  70. Google Scholar, Crossref, Indexed at

  71. Wang, Xun, Zhihui Feng, Xueqiang Wang and Liang Yang, et al. "O-GlcNAcase deficiency suppresses skeletal myogenesis and insulin sensitivity in mice through the modulation of mitochondrial homeostasis."Diabetologia59 (2016): 1287-1296.
  72. Google Scholar, Crossref, Indexed at

  73. Aksnes, Henriette, Rasmus Ree and Thomas Arnesen. "Co-translational, post-translational, and non-catalytic roles of N-terminal acetyltransferases."Mol Cell 73 (2019): 1097-1114.
  74. Google Scholar, Crossref, Indexed at

  75. Lee, Chang-Seok, Sang-Hyeon Mun, Nhung Thimy Truong and Sang Ki Park, et al. "N-terminal acetylation and the N-end rule pathway control degradation of the lipid droplet protein PLIN2."J Biol Chem 294 (2019): 379-388.
  76. Google Scholar, Crossref, Indexed at

  77. Corrado, Domenico, Cristina Basso and Daniel P. Judge. "Arrhythmogenic cardiomyopathy."Circulation research121(2017):784-802.
  78. Google Scholar, Crossref, Indexed at

  79. Erdmann, Jeanette and Alessandra Moretti.“Genetic Causes of Cardiac Disease’’. Springer Nature( 2019).
  80. Google Scholar

  81. Liu, Chao, Qianhao Zhao, Terry Su and Shuangbo Tang, et al. "Postmortem molecular analysis of KCNQ1, KCNH2, KCNE1 and KCNE2 genes in sudden unexplained nocturnal death syndrome in the Chinese han population."Forensic Sci Int 231(2013): 82-87.
  82. Google Scholar, Crossref, Indexed at

  83. Martínez-Barrios, Estefanía, Sergi Cesar, José Cruzalegui and Clara Hernandez, et al. "Clinical genetics of inherited arrhythmogenic disease in the pediatric population."Biomed 10 (2022): 106.
  84. Google Scholar, Crossref, Indexed at

  85. Towbin, Jeffrey A "Inherited cardiomyopathies."Circ J 78 (2014): 2347-2356.
  86. Google Scholar, Crossref, Indexed at

  87. Jain, Shobhit and Gary D. Bader. "An improved method for scoring protein-protein interactions using semantic similarity within the gene ontology."BMC Bioinform 11 (2010): 1-14.
  88. Google Scholar, Crossref, Indexed at

  89. Yeung, Chun-Yip, Karen Siu-Ling Lam, Sheung-Wai Li and Kwok-Fai Lam, et al. "Sudden cardiac death after myocardial infarction in type 2 diabetic patients with no residual myocardial ischemia."Diabetes Care35 (2012): 2564-2569.
  90. Google Scholar, Crossref, Indexed at

  91. Ackerman, Michael, Dianne L. Atkins and John K. Triedman. "Sudden cardiac death in the young."Circulation133 (2016): 1006-1026.
  92. Google Scholar, Crossref, Indexed at

Google Scholar citation report
Citations: 1817

Journal of Forensic Research received 1817 citations as per Google Scholar report

Journal of Forensic Research peer review process verified at publons

Indexed In

 
arrow_upward arrow_upward