1
|
Yang Q, Tadros HJ, Sun B, Bidzimou MT, Ezekian JE, Li F, Ludwig A, Wehrens XH, Landstrom AP. Junctional Ectopic Tachycardia Caused by Junctophilin-2 Expression Silencing Is Selectively Sensitive to Ryanodine Receptor Blockade. JACC Basic Transl Sci 2023; 8:1577-1588. [PMID: 38205351 PMCID: PMC10774596 DOI: 10.1016/j.jacbts.2023.07.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 07/10/2023] [Accepted: 07/10/2023] [Indexed: 01/12/2024]
Abstract
Junctional ectopic tachycardia (JET) is a potentially fatal cardiac arrhythmia. Hcn4:shJph2 mice serve as a model of nodal arrhythmias driven by ryanodine type 2 receptor (RyR2)-mediated Ca2+ leak. EL20 is a small molecule that blocks RyR2 Ca2+ leak. In a novel in vivo model of JET, Hcn4:shJph2 mice demonstrated rapid conversion of JET to sinus rhythm with infusion of EL20. Primary atrioventricular nodal cells demonstrated increased Ca2+ transient oscillation frequency and increased RyR2-mediated stored Ca2+ leak which was normalized by EL20. EL20 was found to be rapidly degraded in mouse and human plasma, making it a potential novel therapy for JET.
Collapse
Affiliation(s)
- Qixin Yang
- Division of Cardiology, Department of Pediatrics, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Cardiology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Hanna J. Tadros
- Section of Cardiology, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Bo Sun
- Division of Cardiology, Department of Pediatrics, Duke University School of Medicine, Durham, North Carolina, USA
| | - Minu-Tshyeto Bidzimou
- Division of Cardiology, Department of Pediatrics, Duke University School of Medicine, Durham, North Carolina, USA
| | - Jordan E. Ezekian
- Division of Cardiology, Department of Pediatrics, Duke University School of Medicine, Durham, North Carolina, USA
| | - Feng Li
- Center for Drug Discovery and Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas, USA
| | - Andreas Ludwig
- Institut für Experimentelle und Klinische Pharmakologie, und Toxikologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Xander H.T. Wehrens
- Section of Cardiology, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
- Cardiovascular Research Institute, Departments of Medicine (Cardiology), Molecular Physiology and Biophysics, and Neuroscience and Center for Space Medicine, Baylor College of Medicine, Houston, Texas, USA
| | - Andrew P. Landstrom
- Division of Cardiology, Department of Pediatrics, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Cell Biology, Duke University School of Medicine, Durham, North Carolina, USA
| |
Collapse
|
2
|
Sooy-Mossey M, Matsuura M, Ezekian JE, Williams JL, Lee GS, Wood K, Dizon S, Kaplan SJ, Li JS, Parente V. The Association of Race and Ethnicity with Mortality in Pediatric Patients with Congenital Heart Disease: a Systematic Review. J Racial Ethn Health Disparities 2023:10.1007/s40615-023-01687-2. [PMID: 37436684 DOI: 10.1007/s40615-023-01687-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 06/09/2023] [Accepted: 06/18/2023] [Indexed: 07/13/2023]
Abstract
CONTEXT Congenital heart disease (CHD) is a common condition with high morbidity and mortality and is subject to racial and ethnic health disparities. OBJECTIVE To conduct a systematic review of the literature to identify differences in mortality in pediatric patients with CHD based on race and ethnicity. DATA SOURCES Legacy PubMed (MEDLINE), Embase (Elsevier), and Scopus (Elsevier) STUDY SELECTION: English language articles conducted in the USA focused on mortality based on race and ethnicity in pediatric patients with CHD. DATA EXTRACTION Two independent reviewers assessed studies for inclusion and performed data extraction and quality assessment. Data extraction included mortality based on patient race and ethnicity. RESULTS There were 5094 articles identified. After de-duplication, 2971 were screened for title and abstract content, and 45 were selected for full-text assessment. Thirty studies were included for data extraction. An additional 8 articles were identified on reference review and included in data extraction for a total of 38 included studies. Eighteen of 26 studies showed increased risk of mortality in non-Hispanic Black patients. Results were heterogenous in Hispanic patients with eleven studies of 24 showing an increased risk of mortality. Results for other races demonstrated mixed outcomes. LIMITATIONS Study cohorts and definitions of race and ethnicity were heterogenous, and there was some overlap in national datasets used. CONCLUSION Overall, racial and ethnic disparities existed in the mortality of pediatric patients with CHD across a variety of mortality types, CHD lesions, and pediatric age ranges. Children of races and ethnicities other than non-Hispanic White generally had increased risk of mortality, with non-Hispanic Black children most consistently having the highest risk of mortality. Further investigation is needed into the underlying mechanisms of these disparities so interventions to reduce inequities in CHD outcomes can be implemented.
Collapse
Affiliation(s)
- Meredith Sooy-Mossey
- Division of Pediatric Cardiology, Department of Pediatrics, Duke University School of Medicine, 2301 Erwin Road, DUMC Box 3127, Durham, NC, 27710, USA.
| | - Mirai Matsuura
- Deparment of Pediatrics, Massachusetts General Hospital, Boston, MA, USA
| | - Jordan E Ezekian
- Division of Cardiology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jason L Williams
- Division of Pediatric Cardiology, Department of Pediatrics, Duke University School of Medicine, 2301 Erwin Road, DUMC Box 3127, Durham, NC, 27710, USA
| | - Grace S Lee
- Department of Pediatrics, Duke University School of Medicine, Durham, NC, USA
| | - Kathleen Wood
- Division of Pediatric Cardiology, Department of Pediatrics, Duke University School of Medicine, 2301 Erwin Road, DUMC Box 3127, Durham, NC, 27710, USA
| | - Samantha Dizon
- Division of Cardiology, Columbia University Department of Medicine, New York, NY, USA
| | - Samantha J Kaplan
- Medical Center Library and Archives, Duke University, Durham, NC, USA
| | - Jennifer S Li
- Division of Pediatric Cardiology, Department of Pediatrics, Duke University School of Medicine, 2301 Erwin Road, DUMC Box 3127, Durham, NC, 27710, USA
| | - Victoria Parente
- Pediatric Hospital Medicine, Duke University School of Medicine, Durham, NC, USA
| |
Collapse
|
3
|
Yang Q, Berkman AM, Ezekian JE, Rosamilia M, Rosenfeld JA, Liu P, Landstrom AP. Determining the Likelihood of Disease Pathogenicity Among Incidentally Identified Genetic Variants in Rare Dilated Cardiomyopathy-Associated Genes. J Am Heart Assoc 2022; 11:e025257. [PMID: 36129056 DOI: 10.1161/jaha.122.025257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background As utilization of clinical exome sequencing (ES) has expanded, criteria for evaluating the diagnostic weight of incidentally identified variants are critical to guide clinicians and researchers. This is particularly important in genes associated with dilated cardiomyopathy (DCM), which can cause heart failure and sudden death. We sought to compare the frequency and distribution of incidentally identified variants in DCM-associated genes between a clinical referral cohort with those in control and known case cohorts to determine the likelihood of pathogenicity among those undergoing genetic testing for non-DCM indications. Methods and Results A total of 39 rare, non-TTN DCM-associated genes were identified and evaluated from a clinical ES testing referral cohort (n=14 005, Baylor Genetic Laboratories) and compared with a DCM case cohort (n=9442) as well as a control cohort of population variants (n=141 456) derived from the gnomAD database. Variant frequencies in each cohort were compared. Signal-to-noise ratios were calculated comparing the DCM and ES cohort with the gnomAD cohort. The likely pathogenic/pathogenic variant yield in the DCM cohort (8.2%) was significantly higher than in the ES cohort (1.9%). Based on signal-to-noise and correlation analysis, incidental variants found in FLNC, RBM20, MYH6, DSP, ABCC9, JPH2, and NEXN had the greatest chance of being DCM-associated. Conclusions The distribution of pathogenic variants between the ES cohort and the DCM case cohort was gene specific, and variants found in the ES cohort were similar to variants found in the control cohort. Incidentally identified variants in specific genes are more associated with DCM than others.
Collapse
Affiliation(s)
- Qixin Yang
- Department of Pediatrics, Division of Cardiology Duke University School of Medicine Durham NC.,Department of Cardiology The First Affiliated Hospital, College of Medicine, Zhejiang University Hangzhou China
| | - Amy M Berkman
- Department of Pediatrics, Division of Cardiology Duke University School of Medicine Durham NC
| | - Jordan E Ezekian
- Department of Pediatrics, Division of Cardiology Duke University School of Medicine Durham NC
| | - Michael Rosamilia
- Department of Pediatrics, Division of Cardiology Duke University School of Medicine Durham NC
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics Baylor College of Medicine and Baylor Genetics Laboratories Houston TX
| | - Pengfei Liu
- Department of Molecular and Human Genetics Baylor College of Medicine and Baylor Genetics Laboratories Houston TX
| | - Andrew P Landstrom
- Department of Pediatrics, Division of Cardiology Duke University School of Medicine Durham NC.,Department of Cell Biology Duke University School of Medicine Durham NC
| |
Collapse
|
4
|
Ezekian JE, Stephenson EA. Postnatal Outcomes of Fetal SVT: Can We Predict the Future? JACC Clin Electrophysiol 2022; 8:1152-1154. [PMID: 36137721 DOI: 10.1016/j.jacep.2022.07.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 07/10/2022] [Indexed: 11/19/2022]
Affiliation(s)
- Jordan E Ezekian
- Department of Paediatrics, Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Elizabeth A Stephenson
- Department of Paediatrics, Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
| |
Collapse
|
5
|
Draelos RL, Ezekian JE, Zhuang F, Moya-Mendez ME, Zhang Z, Rosamilia MB, Manivannan PKR, Henao R, Landstrom AP. GENESIS: Gene-Specific Machine Learning Models for Variants of Uncertain Significance Found in Catecholaminergic Polymorphic Ventricular Tachycardia and Long QT Syndrome-Associated Genes. Circ Arrhythm Electrophysiol 2022; 15:e010326. [PMID: 35357185 PMCID: PMC9018586 DOI: 10.1161/circep.121.010326] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Cardiac channelopathies such as catecholaminergic polymorphic tachycardia and long QT syndrome predispose patients to fatal arrhythmias and sudden cardiac death. As genetic testing has become common in clinical practice, variants of uncertain significance (VUS) in genes associated with catecholaminergic polymorphic ventricular tachycardia and long QT syndrome are frequently found. The objective of this study was to predict pathogenicity of catecholaminergic polymorphic ventricular tachycardia-associated RYR2 VUS and long QT syndrome-associated VUS in KCNQ1, KCNH2, and SCN5A by developing gene-specific machine learning models and assessing them using cross-validation, cellular electrophysiological data, and clinical correlation. METHODS The GENe-specific EnSemble grId Search framework was developed to identify high-performing machine learning models for RYR2, KCNQ1, KCNH2, and SCN5A using variant- and protein-specific inputs. Final models were applied to datasets of VUS identified from ClinVar and exome sequencing. Whole cell patch clamp and clinical correlation of selected VUS was performed. RESULTS The GENe-specific EnSemble grId Search models outperformed alternative methods, with area under the receiver operating characteristics up to 0.87, average precisions up to 0.83, and calibration slopes as close to 1.0 (perfect) as 1.04. Blinded voltage-clamp analysis of HEK293T cells expressing 2 predicted pathogenic variants in KCNQ1 each revealed an ≈80% reduction of peak Kv7.1 current compared with WT. Normal Kv7.1 function was observed in KCNQ1-V241I HEK cells as predicted. Though predicted benign, loss of Kv7.1 function was observed for KCNQ1-V106D HEK cells. Clinical correlation of 9/10 variants supported model predictions. CONCLUSIONS Gene-specific machine learning models may have a role in post-genetic testing diagnostic analyses by providing high performance prediction of variant pathogenicity.
Collapse
Affiliation(s)
- Rachel L Draelos
- Department of Computer Science, Trinity College of Arts and Sciences (R.L.D., F.Z.), Duke University.,Medical Scientist Training Program (R.L.D.), Duke University School of Medicine, Durham, NC
| | - Jordan E Ezekian
- Department of Pediatrics, Division of Cardiology (J.E.Z., M.E.M.-M., Z.Z., M.B.R., P.K.R.M., A.P.L.), Duke University School of Medicine, Durham, NC
| | - Farica Zhuang
- Department of Computer Science, Trinity College of Arts and Sciences (R.L.D., F.Z.), Duke University
| | - Mary E Moya-Mendez
- Department of Pediatrics, Division of Cardiology (J.E.Z., M.E.M.-M., Z.Z., M.B.R., P.K.R.M., A.P.L.), Duke University School of Medicine, Durham, NC
| | - Zhushan Zhang
- Department of Pediatrics, Division of Cardiology (J.E.Z., M.E.M.-M., Z.Z., M.B.R., P.K.R.M., A.P.L.), Duke University School of Medicine, Durham, NC
| | - Michael B Rosamilia
- Department of Pediatrics, Division of Cardiology (J.E.Z., M.E.M.-M., Z.Z., M.B.R., P.K.R.M., A.P.L.), Duke University School of Medicine, Durham, NC
| | - Perathu K R Manivannan
- Department of Pediatrics, Division of Cardiology (J.E.Z., M.E.M.-M., Z.Z., M.B.R., P.K.R.M., A.P.L.), Duke University School of Medicine, Durham, NC
| | - Ricardo Henao
- Department of Electrical and Computer Engineering, Pratt School of Engineering (R.H.), Duke University.,Department of Biostatistics and Bioinformatics (R.H.), Duke University School of Medicine, Durham, NC
| | - Andrew P Landstrom
- Department of Pediatrics, Division of Cardiology (J.E.Z., M.E.M.-M., Z.Z., M.B.R., P.K.R.M., A.P.L.), Duke University School of Medicine, Durham, NC.,Department of Cell Biology (A.P.L.), Duke University School of Medicine, Durham, NC
| |
Collapse
|
6
|
Moya-Mendez ME, Ogbonna C, Ezekian JE, Rosamilia MB, Prange L, de la Uz C, Kim JJ, Howard T, Garcia J, Nussbaum R, Truty R, Callis TE, Funk E, Heyes M, Dear GDL, Carboni MP, Idriss SF, Mikati MA, Landstrom AP. ATP1A3-Encoded Sodium-Potassium ATPase Subunit Alpha 3 D801N Variant Is Associated With Shortened QT Interval and Predisposition to Ventricular Fibrillation Preceded by Bradycardia. J Am Heart Assoc 2021; 10:e019887. [PMID: 34459253 PMCID: PMC8649289 DOI: 10.1161/jaha.120.019887] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Background Pathogenic variation in the ATP1A3‐encoded sodium‐potassium ATPase, ATP1A3, is responsible for alternating hemiplegia of childhood (AHC). Although these patients experience a high rate of sudden unexpected death in epilepsy, the pathophysiologic basis for this risk remains unknown. The objective was to determine the role of ATP1A3 genetic variants on cardiac outcomes as determined by QT and corrected QT (QTc) measurements. Methods and Results We analyzed 12‐lead ECG recordings from 62 patients (male subjects=31, female subjects=31) referred for AHC evaluation. Patients were grouped according to AHC presentation (typical versus atypical), ATP1A3 variant status (positive versus negative), and ATP1A3 variant (D801N versus other variants). Manual remeasurements of QT intervals and QTc calculations were performed by 2 pediatric electrophysiologists. QTc measurements were significantly shorter in patients with positive ATP1A3 variant status (P<0.001) than in patients with genotype‐negative status, and significantly shorter in patients with the ATP1A3‐D801N variant than patients with other variants (P<0.001). The mean QTc for ATP1A3‐D801N was 344.9 milliseconds, which varied little with age, and remained <370 milliseconds throughout adulthood. ATP1A3 genotype status was significantly associated with shortened QTc by multivariant regression analysis. Two patients with the ATP1A3‐D801N variant experienced ventricular fibrillation, resulting in death in 1 patient. Rare variants in ATP1A3 were identified in a large cohort of genotype‐negative patients referred for arrhythmia and sudden unexplained death. Conclusions Patients with AHC who carry the ATP1A3‐D801N variant have significantly shorter QTc intervals and an increased likelihood of experiencing bradycardia associated with life‐threatening arrhythmias. ATP1A3 variants may represent an independent cause of sudden unexplained death. Patients with AHC should be evaluated to identify risk of sudden death.
Collapse
Affiliation(s)
- Mary E Moya-Mendez
- Department of Pediatrics Division of Pediatric Cardiology Duke University School of Medicine Durham NC
| | - Chiagoziem Ogbonna
- Department of Pediatrics Division of Pediatric Cardiology Duke University School of Medicine Durham NC
| | - Jordan E Ezekian
- Department of Pediatrics Division of Pediatric Cardiology Duke University School of Medicine Durham NC
| | - Michael B Rosamilia
- Department of Pediatrics Division of Pediatric Cardiology Duke University School of Medicine Durham NC
| | - Lyndsey Prange
- Department of Pediatrics Division of Neurology Duke University School of Medicine Durham NC
| | - Caridad de la Uz
- Department of Pediatrics Division of Cardiology Johns Hopkins School of Medicine Baltimore MD
| | - Jeffrey J Kim
- Department of Pediatrics Section of Cardiology Baylor College of Medicine Houston TX
| | - Taylor Howard
- Department of Pediatrics Section of Cardiology Baylor College of Medicine Houston TX
| | | | | | | | | | - Emily Funk
- Duke University School of NursingAssistant Clinical ProfessorDuke University Durham NC
| | - Matthew Heyes
- Duke University School of NursingAssistant Clinical ProfessorDuke University Durham NC
| | - Guy de Lisle Dear
- Department of Anesthesia Duke University School of Medicine Durham NC
| | - Michael P Carboni
- Department of Pediatrics Division of Pediatric Cardiology Duke University School of Medicine Durham NC
| | - Salim F Idriss
- Department of Pediatrics Division of Pediatric Cardiology Duke University School of Medicine Durham NC
| | - Mohamad A Mikati
- Department of Pediatrics Division of Neurology Duke University School of Medicine Durham NC
| | - Andrew P Landstrom
- Department of Pediatrics Division of Pediatric Cardiology Duke University School of Medicine Durham NC.,Department of Cell Biology Duke University School of Medicine Durham NC
| |
Collapse
|
7
|
Ezekian JE, Rehder C, Kishnani PS, Landstrom AP. Interpretation of Incidental Genetic Findings Localizing to Genes Associated With Cardiac Channelopathies and Cardiomyopathies. Circ Genom Precis Med 2021; 14:e003200. [PMID: 34384235 DOI: 10.1161/circgen.120.003200] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Recent advances in next-genetic sequencing technology have facilitated an expansion in the use of exome and genome sequencing in the research and clinical settings. While this has aided in the genetic diagnosis of individuals with atypical clinical presentations, there has been a marked increase in the number of incidentally identified variants of uncertain diagnostic significance in genes identified as clinically actionable by the American College of Medical Genetics guidelines. Approximately 20 of these genes are associated with cardiac diseases, which carry a significant risk of sudden cardiac death. While identification of at-risk individuals is paramount, increased discovery of incidental variants of uncertain diagnostic significance has placed a burden on the clinician tasked with determining the diagnostic significance of these findings. Herein, we describe the scope of this emerging problem using cardiovascular genetics to illustrate the challenges associated with variants of uncertain diagnostic significance interpretation. We review the evidence for diagnostic weight of these variants, discuss the role of clinical genetics providers in patient care, and put forward general recommendations about the interpretation of incidentally identified variants found with clinical genetic testing.
Collapse
Affiliation(s)
- Jordan E Ezekian
- Division of Cardiology, Department of Pediatrics (J.E.E., A.P.L.), Duke University School of Medicine, Durham, NC
| | - Catherine Rehder
- Department of Pathology (C.R.), Duke University School of Medicine, Durham, NC
| | - Priya S Kishnani
- Division of Medical Genetics, Department of Pediatrics (P.S.K.), Duke University School of Medicine, Durham, NC
| | - Andrew P Landstrom
- Division of Cardiology, Department of Pediatrics (J.E.E., A.P.L.), Duke University School of Medicine, Durham, NC.,Department of Cell Biology (A.P.L.), Duke University School of Medicine, Durham, NC
| |
Collapse
|
8
|
Moya-Mendez ME, Ogbonna C, Parker L, Ezekian JE, Prange L, La Uz CD, Kim JJ, Howard TS, Funk E, Hayes M, Lisle Dear GD, Carboni MP, Idriss SF, Mikati MA, Landstrom AP. B-PO04-191 ASSOCIATION BETWEEN SHORTENED QT INTERVAL AND BRADYCARDIA WITH THE D801N VARIANT OF ATP1A3 IN PATIENTS WITH ALTERNATING HEMIPLEGIA OF CHILDHOOD. Heart Rhythm 2021. [DOI: 10.1016/j.hrthm.2021.06.883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
9
|
Markunas A, Ezekian JE, Landstrom AP. B-PO04-025 SIGNAL-TO-NOISE ANALYSIS OF MISSENSE VARIANTS WITHIN TBX5 SUGGESTS PRESENCE OF PHENOTYPE EXPRESSION-SPECIFIC VARIANT HOTSPOTS. Heart Rhythm 2021. [DOI: 10.1016/j.hrthm.2021.06.721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
10
|
Markunas AM, Manivannan PKR, Ezekian JE, Agarwal A, Eisner W, Alsina K, Allen HD, Wray GA, Kim JJ, Wehrens XHT, Landstrom AP. TBX5-encoded T-box transcription factor 5 variant T223M is associated with long QT syndrome and pediatric sudden cardiac death. Am J Med Genet A 2020; 185:923-929. [PMID: 33369127 DOI: 10.1002/ajmg.a.62037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 11/27/2020] [Accepted: 12/01/2020] [Indexed: 12/14/2022]
Abstract
Long QT syndrome (LQTS) is a genetic disease resulting in a prolonged QT interval on a resting electrocardiogram, predisposing affected individuals to polymorphic ventricular tachycardia and sudden death. Although a number of genes have been implicated in this disease, nearly one in four individuals exhibiting the LQTS phenotype are genotype-negative. Whole-exome sequencing identified a missense T223M variant in TBX5 that cosegregates with prolonged QT interval in a family with otherwise genotype-negative LQTS and sudden death. The TBX5-T223M variant was absent among large ostensibly healthy populations (gnomAD) and predicted to be pathogenic by in silico modeling based on Panther, PolyPhen-2, Provean, SIFT, SNAP2, and PredictSNP prediction tools. The variant was located in a highly conserved region of TBX5 predicted to be part of the DNA-binding interface. A luciferase assay identified a 57.5% reduction in the ability of TBX5-T223M to drive expression at the atrial natriuretic factor promotor compared to wildtype TBX5 in vitro. We conclude that the variant is pathogenic in this family, and we put TBX5 forward as a disease susceptibility allele for genotype-negative LQTS. The identification of this familial variant may serve as a basis for the identification of previously unknown mechanisms of LQTS with broader implications for cardiac electrophysiology.
Collapse
Affiliation(s)
- Alexandra M Markunas
- Department of Pediatrics, Division of Cardiology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Perathu K R Manivannan
- Department of Pediatrics, Division of Cardiology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Jordan E Ezekian
- Department of Pediatrics, Division of Cardiology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Agnim Agarwal
- Department of Biology, Duke University, Durham, North Carolina, USA
| | - William Eisner
- Department of Pediatrics, Division of Cardiology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Katherina Alsina
- Departments of Molecular Physiology & Biophysics and Medicine (Cardiology), Baylor College of Medicine, Houston, Texas, USA
| | - Hugh D Allen
- Department of Pediatrics, Section of Cardiology, Baylor College of Medicine, Houston, Texas, USA
| | - Gregory A Wray
- Department of Biology, Duke University, Durham, North Carolina, USA
| | - Jeffrey J Kim
- Department of Pediatrics, Section of Cardiology, Baylor College of Medicine, Houston, Texas, USA
| | - Xander H T Wehrens
- Departments of Molecular Physiology & Biophysics and Medicine (Cardiology), Baylor College of Medicine, Houston, Texas, USA
| | - Andrew P Landstrom
- Department of Pediatrics, Division of Cardiology, Duke University School of Medicine, Durham, North Carolina, USA.,Department of Cell Biology, Duke University School of Medicine, Durham, North Carolina, USA
| |
Collapse
|
11
|
Ezekian JE, Clippinger SR, Garcia JM, Yang Q, Denfield S, Jeewa A, Dreyer WJ, Zou W, Fan Y, Allen HD, Kim JJ, Greenberg MJ, Landstrom AP. Variant R94C in TNNT2-Encoded Troponin T Predisposes to Pediatric Restrictive Cardiomyopathy and Sudden Death Through Impaired Thin Filament Relaxation Resulting in Myocardial Diastolic Dysfunction. J Am Heart Assoc 2020; 9:e015111. [PMID: 32098556 PMCID: PMC7335540 DOI: 10.1161/jaha.119.015111] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Background Pediatric‐onset restrictive cardiomyopathy (RCM) is associated with high mortality, but underlying mechanisms of disease are under investigated. RCM‐associated diastolic dysfunction secondary to variants in TNNT2‐encoded cardiac troponin T (TNNT2) is poorly described. Methods and Results Genetic analysis of a proband and kindred with RCM identified TNNT2‐R94C, which cosegregated in a family with 2 generations of RCM, ventricular arrhythmias, and sudden death. TNNT2‐R94C was absent among large, population‐based cohorts Genome Aggregation Database (gnomAD) and predicted to be pathologic by in silico modeling. Biophysical experiments using recombinant human TNNT2‐R94C demonstrated impaired cardiac regulation at the molecular level attributed to reduced calcium‐dependent blocking of myosin's interaction with the thin filament. Computational modeling predicted a shift in the force‐calcium curve for the R94C mutant toward submaximal calcium activation compared within the wild type, suggesting low levels of muscle activation even at resting calcium concentrations and hypercontractility following activation by calcium. Conclusions The pathogenic TNNT2‐R94C variant activates thin‐filament–mediated sarcomeric contraction at submaximal calcium concentrations, likely resulting in increased muscle tension during diastole and hypercontractility during systole. This describes the proximal biophysical mechanism for development of RCM in this family.
Collapse
Affiliation(s)
- Jordan E Ezekian
- Division of Paediatric Cardiology Department of Pediatrics Duke University School of Medicine Durham NC
| | - Sarah R Clippinger
- Department of Biochemistry and Molecular Biophysics Washington University in St. Louis St. Louis MO
| | - Jaquelin M Garcia
- Department of Biochemistry and Molecular Biophysics Washington University in St. Louis St. Louis MO
| | - Qixin Yang
- Division of Paediatric Cardiology Department of Pediatrics Duke University School of Medicine Durham NC
| | - Susan Denfield
- Department of Pediatrics The Lillie Frank Abercrombie Section of Pediatric Cardiology Baylor College of Medicine Houston TX
| | - Aamir Jeewa
- Department of Pediatrics The Hospital for Sick Children Toronto Ontario Canada
| | - William J Dreyer
- Department of Pediatrics The Lillie Frank Abercrombie Section of Pediatric Cardiology Baylor College of Medicine Houston TX
| | - Wenxin Zou
- Department of Pediatrics The Lillie Frank Abercrombie Section of Pediatric Cardiology Baylor College of Medicine Houston TX
| | - Yuxin Fan
- Department of Pediatrics The Lillie Frank Abercrombie Section of Pediatric Cardiology Baylor College of Medicine Houston TX
| | - Hugh D Allen
- Department of Pediatrics The Lillie Frank Abercrombie Section of Pediatric Cardiology Baylor College of Medicine Houston TX
| | - Jeffrey J Kim
- Department of Pediatrics The Lillie Frank Abercrombie Section of Pediatric Cardiology Baylor College of Medicine Houston TX
| | - Michael J Greenberg
- Department of Biochemistry and Molecular Biophysics Washington University in St. Louis St. Louis MO
| | - Andrew P Landstrom
- Division of Paediatric Cardiology Department of Pediatrics Duke University School of Medicine Durham NC.,Department of Cell Biology Duke University School of Medicine Durham NC
| |
Collapse
|
12
|
Chamberlain RC, Ezekian JE, Sturgeon GM, Barker PCA, Hill KD, Fleming GA. Preprocedural three-dimensional planning aids in transcatheter ductal stent placement: A single-center experience. Catheter Cardiovasc Interv 2019; 95:1141-1148. [PMID: 31854085 DOI: 10.1002/ccd.28669] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 11/05/2019] [Accepted: 12/07/2019] [Indexed: 12/17/2022]
Abstract
OBJECTIVES Describe the use of three-dimensional (3D) patent ductus arteriosus (PDA) modeling to better define ductal anatomy to improve preprocedural planning for ductal stent placement. BACKGROUND Ductal stenting is an alternative to surgical shunting in patients with ductal dependent pulmonary blood flow. Ductal anatomy is often complex with extreme tortuosity and risk of pulmonary artery isolation, thus increasing procedural risks. METHODS CT angiograms were segmented to produce 3D PDA models. Ductal morphology was characterized with attention to access approach, degree of pulmonary artery offset/risk of isolation and ductal tortuosity. 3D models were retrospectively compared with biplane angiography. RESULTS 3D modeling was performed in 12 patients with adequate image quality for complete analysis in 11; median (interquartile range) age/weight 17 days (8-20 days) and 3.1 kg (2.4-3.9 kg). The PDA was reverse oriented in nine with average length of 17.2 ± 2.5 mm and high tortuosity (mean tortuosity index 52, range 3-108). From 3D modeling, two patients were excluded from ductal stenting-extreme ductal tortuosity and threatened pulmonary artery discontinuity, respectively. Ductal stenting was successful in the remaining nine with no major procedural complications. 3D modeling predicted a successful access approach based on the aortic orientation of the ductus in all patients (five carotid, two axillary, two femoral). When comparing 2D angiography with 3D models, angiography consistently underestimated ductal length (-3.2 mm ± 1.6 mm) and tortuosity (-14.8 ± 7.2). CONCLUSIONS 3D modeling prior to ductal stent placement for ductal dependent pulmonary blood flow is useful in procedural planning, specifically for eligibility, access approach, and accurate ductal measurements. Further studies are needed to determine if 3D planning improves procedural outcomes.
Collapse
Affiliation(s)
- Reid C Chamberlain
- Department of Pediatrics, Division of Pediatric Cardiology, Duke University Medical Center, Durham, North Carolina
| | - Jordan E Ezekian
- Department of Pediatrics, Division of Pediatric Cardiology, Duke University Medical Center, Durham, North Carolina
| | - Gregory M Sturgeon
- Department of Pediatrics, Division of Pediatric Cardiology, Duke University Medical Center, Durham, North Carolina
| | - Piers C A Barker
- Department of Pediatrics, Division of Pediatric Cardiology, Duke University Medical Center, Durham, North Carolina
| | - Kevin D Hill
- Department of Pediatrics, Division of Pediatric Cardiology, Duke University Medical Center, Durham, North Carolina
| | - Gregory A Fleming
- Department of Pediatrics, Division of Pediatric Cardiology, Duke University Medical Center, Durham, North Carolina
| |
Collapse
|
13
|
Abstract
PURPOSE OF REVIEW Pediatric pulmonary arterial hypertension (PAH) is associated with significant morbidity and mortality. Herein we review the diagnosis and classification for pediatric PAH and detail the current therapeutic options available for use in the pediatric PAH population. RECENT FINDINGS Classification and treatment of pediatric PAH is guided by adult criteria and treatment algorithms, yet the distribution of factors contributing to PAH in children differs significantly from that seen in adults. It is necessary to understand these differences in order to appropriately tailor therapy to the needs of the child or adolescent. An expanding array of targeted PAH drugs are now approved for use in adults, and many of these drugs are used "off-label" to treat children and adolescents with PAH. Use of these novel therapies has coincided with marked improvement in outcomes, suggesting significant benefit. However, because most of these drugs have not been studied in rigorous randomized, controlled trials in children, it is critical that physicians understand their mechanisms of action, potential benefits, and safety profiles. Pediatric PAH outcomes have improved substantially in the modern era, coinciding with the "off-label" use of targeted PAH drugs in children and adolescents. Ideally, care should be provided at centers with specialized expertise in the diagnosis and treatment of pediatric PAH by providers who understand the appropriate diagnostic algorithms, classification schemes, and treatment approaches.
Collapse
Affiliation(s)
- Jordan E Ezekian
- Department of Pediatrics, Division of Pediatric Cardiology, Duke University Medical Center, 2301 Erwin Road, DUMC, Box 3090, Durham, NC, 27710, USA
| | - Kevin D Hill
- Department of Pediatrics, Division of Pediatric Cardiology, Duke University Medical Center, 2301 Erwin Road, DUMC, Box 3090, Durham, NC, 27710, USA.
| |
Collapse
|