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Boen HM, Alaerts M, Van Laer L, Saenen JB, Goovaerts I, Bastianen J, Koopman P, Vanduynhoven P, De Vuyst E, Rosseel M, Heidbuchel H, Van Craenenbroeck EM, Loeys B. Phenotypic spectrum of the first Belgian MYBPC3 founder: a large multi-exon deletion with a varying phenotype. Front Genet 2024; 15:1392527. [PMID: 38836037 PMCID: PMC11148247 DOI: 10.3389/fgene.2024.1392527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 04/22/2024] [Indexed: 06/06/2024] Open
Abstract
Background Variants in the MYBPC3 gene are a frequent cause of hypertrophic cardiomyopathy (HCM) but display a large phenotypic heterogeneity. Founder mutations are often believed to be more benign as they prevailed despite potential negative selection pressure. We detected a pathogenic variant in MYBPC3 (del exon 23-26) in several probands. We aimed to assess the presence of a common haplotype and to describe the cardiac characteristics, disease severity and long-term outcome of mutation carriers. Methods Probands with HCM caused by a pathogenic deletion of exon 23-26 of MYBPC3 were identified through genetic screening using a gene panel encompassing 59 genes associated with cardiomyopathies in a single genetic center in Belgium. Cascade screening of first-degree relatives was performed, and genotype positive relatives were further phenotyped. Clinical characteristics were collected from probands and relatives. Cardiac outcomes included death, heart transplantation, life-threatening arrhythmia, heart failure hospitalization or septal reduction therapy. Haplotype analysis, using microsatellite markers surrounding MYBPC3, was performed in all index patients to identify a common haplotype. The age of the founder variant was estimated based on the size of the shared haplotype using a linkage-disequilibrium based approach. Results We identified 24 probands with HCM harbouring the MYBPC3 exon 23-26 deletion. Probands were on average 51 ± 16 years old at time of clinical HCM diagnosis and 62 ± 10 years old at time of genetic diagnosis. A common haplotype of 1.19 Mb was identified in all 24 probands, with 19 of the probands sharing a 13.8 Mb haplotype. The founder event was estimated to have happened five generations, or 175-200 years ago, around the year 1830 in central Flanders. Through cascade screening, 59 first-degree relatives were genetically tested, of whom 37 (62.7%) were genotype positive (G+) and 22 (37.3%) genotype negative (G-). They were on average 38 ± 19 years old at time of genetic testing. Subsequent clinical assessment revealed a HCM phenotype in 19 (51.4%) G+ relatives. Probands were older (63 ± 10 vs. 42 ± 21 years; p < 0.001) and had more severe phenotypes than G+ family members, presenting with more symptoms (50% vs. 13.5%; p = 0.002), arrhythmia (41.7% vs. 12.9%, p = 0.014), more overt hypertrophy and left ventricular outflow tract obstruction (43.5% vs. 3.0%; p < 0.001). Male G+ relatives more often had a HCM phenotype (78.6% vs. 34.8%; p = 0.010) and were more severely affected than females. At the age of 50, a penetrance of 78.6% was observed, defined as the presence of HCM in 11 of 14 G+ relatives with age ≥50 years. Overall, 20.3% of all variant carriers developed one of the predefined cardiac outcomes after a median follow-up of 5.5 years with an average age of 50 (±21) years. Conclusion A Belgian founder variant, an exon 23-26 deletion in MYBPC3, was identified in 24 probands and 37 family members. The variant is characterized by a high penetrance of 78.6% at the age of 50 years but has variable phenotypic expression. Adverse outcomes were observed in 20.3% of patients during follow-up.
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Affiliation(s)
- Hanne M Boen
- Research Group Cardiovascular Diseases, Genetics, Pharmacology and Physiopathology of Heart, Blood Vessels and Skeleton (GENCOR) Department, University of Antwerp, Antwerp, Belgium
- Department of Cardiology, Antwerp University Hospital, Antwerp, Belgium
| | - Maaike Alaerts
- Center of Medical Genetics, Cardiogenomics, Genetics, Pharmacology and Physiopathology of Heart, Blood Vessels and Skeleton (GENCOR) Department, Antwerp University Hospital and University of Antwerp, Antwerp, Belgium
| | - Lut Van Laer
- Center of Medical Genetics, Cardiogenomics, Genetics, Pharmacology and Physiopathology of Heart, Blood Vessels and Skeleton (GENCOR) Department, Antwerp University Hospital and University of Antwerp, Antwerp, Belgium
| | - Johan B Saenen
- Research Group Cardiovascular Diseases, Genetics, Pharmacology and Physiopathology of Heart, Blood Vessels and Skeleton (GENCOR) Department, University of Antwerp, Antwerp, Belgium
- Department of Cardiology, Antwerp University Hospital, Antwerp, Belgium
| | - Inge Goovaerts
- Department of Cardiology, Antwerp University Hospital, Antwerp, Belgium
- Center of Medical Genetics, Cardiogenomics, Genetics, Pharmacology and Physiopathology of Heart, Blood Vessels and Skeleton (GENCOR) Department, Antwerp University Hospital and University of Antwerp, Antwerp, Belgium
| | - Jarl Bastianen
- Center of Medical Genetics, Cardiogenomics, Genetics, Pharmacology and Physiopathology of Heart, Blood Vessels and Skeleton (GENCOR) Department, Antwerp University Hospital and University of Antwerp, Antwerp, Belgium
| | - Pieter Koopman
- Hartcentrum Hasselt, Jessa Hospital Hasselt, Hasselt, Belgium
| | | | | | | | - Hein Heidbuchel
- Research Group Cardiovascular Diseases, Genetics, Pharmacology and Physiopathology of Heart, Blood Vessels and Skeleton (GENCOR) Department, University of Antwerp, Antwerp, Belgium
- Department of Cardiology, Antwerp University Hospital, Antwerp, Belgium
| | - Emeline M Van Craenenbroeck
- Research Group Cardiovascular Diseases, Genetics, Pharmacology and Physiopathology of Heart, Blood Vessels and Skeleton (GENCOR) Department, University of Antwerp, Antwerp, Belgium
- Department of Cardiology, Antwerp University Hospital, Antwerp, Belgium
| | - Bart Loeys
- Center of Medical Genetics, Cardiogenomics, Genetics, Pharmacology and Physiopathology of Heart, Blood Vessels and Skeleton (GENCOR) Department, Antwerp University Hospital and University of Antwerp, Antwerp, Belgium
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Amr A, Koelemen J, Reich C, Sedaghat-Hamedani F, Kayvanpour E, Haas J, Frese K, Lehmann D, Katus HA, Frey N, Meder B. Improving sudden cardiac death risk stratification in hypertrophic cardiomyopathy using established clinical variables and genetic information. Clin Res Cardiol 2024; 113:728-736. [PMID: 37792019 PMCID: PMC11026183 DOI: 10.1007/s00392-023-02310-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 09/14/2023] [Indexed: 10/05/2023]
Abstract
BACKGROUND AND AIMS The cardiac societies of Europe and the United States have established different risk models for preventing sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM). The aim of this study is to validate current SCD risk prediction methods in a German HCM cohort and to improve them by the addition of genotype information. METHODS HCM patients without prior SCD or equivalent arrhythmic events ≥ 18 years of age were enrolled in an expert cardiomyopathy center in Germany. The primary endpoint was defined as SCD/-equivalent within 5 years of baseline evaluation. 5-year SCD-risk estimates and recommendations for ICD implantations, as defined by the ESC and AHA/ACC guidelines, were analyzed. Multivariate cox proportional hazards analyses were integrated with genetic findings as additive SCD risk. RESULTS 283 patients were included and followed for in median 5.77 years (2.92; 8.85). A disease-causing variant was found in 138 (49%) patients. 14 (5%) patients reached the SCD endpoint (5-year incidence 4.9%). Kaplan-Meier survival analysis shows significantly lower overall SCD event-free survival for patients with an identified disease-causing variant (p < 0.05). The ESC HCM Risk-SCD model showed an area-under-the-curve (AUC) of 0.74 (95% CI 0.68-0.79; p < 0.0001) with a sensitivity of 0.29 (95% CI 0.08-0.58) and specificity of 0.83 (95% CI 0.78-0.88) for a risk estimate ≥ 6%/5-years. By comparison, the AHA/ACC HCM SCD risk stratification model showed an AUC of 0.70 (95% CI 0.65-0.76; p = 0.003) with a sensitivity of 0.93 (95% CI, 0.66-0.998) and specificity of 0.28 (95% CI 0.23-0.34) at the respective cut-off. The modified SCD Risk Score with genetic information yielded an AUC of 0.76 (95% CI 0.71-0.81; p < 0.0001) with a sensitivity of 0.86 (95% CI 0.57-0.98) and specificity of 0.69 (95% CI 0.63-0.74). The number-needed-to-treat (NNT) to prevent 1 SCD event by prophylactic ICD-implantation is 13 for the ESC model, 28 for AHA/ACC and 9 for the modified Genotype-model. CONCLUSION This study confirms the performance of current risk models in clinical decision making. The integration of genetic findings into current SCD risk stratification methods seem feasible and can add in decision making, especially in borderline risk-groups. A subgroup of patients with high SCD risk remains unidentified by current risk scores.
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Affiliation(s)
- Ali Amr
- Institute for Cardiomyopathies & Center for Cardiogenetics, Department of Medicine III, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Standort Heidelberg/Mannheim, 69120, Heidelberg, Germany
| | - Jan Koelemen
- Institute for Cardiomyopathies & Center for Cardiogenetics, Department of Medicine III, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Standort Heidelberg/Mannheim, 69120, Heidelberg, Germany
| | - Christoph Reich
- Institute for Cardiomyopathies & Center for Cardiogenetics, Department of Medicine III, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Standort Heidelberg/Mannheim, 69120, Heidelberg, Germany
| | - Farbod Sedaghat-Hamedani
- Institute for Cardiomyopathies & Center for Cardiogenetics, Department of Medicine III, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Standort Heidelberg/Mannheim, 69120, Heidelberg, Germany
| | - Elham Kayvanpour
- Institute for Cardiomyopathies & Center for Cardiogenetics, Department of Medicine III, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Standort Heidelberg/Mannheim, 69120, Heidelberg, Germany
| | - Jan Haas
- Institute for Cardiomyopathies & Center for Cardiogenetics, Department of Medicine III, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Standort Heidelberg/Mannheim, 69120, Heidelberg, Germany
| | - Karen Frese
- Institute for Cardiomyopathies & Center for Cardiogenetics, Department of Medicine III, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Standort Heidelberg/Mannheim, 69120, Heidelberg, Germany
| | - David Lehmann
- Institute for Cardiomyopathies & Center for Cardiogenetics, Department of Medicine III, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Standort Heidelberg/Mannheim, 69120, Heidelberg, Germany
| | - Hugo A Katus
- Institute for Cardiomyopathies & Center for Cardiogenetics, Department of Medicine III, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Standort Heidelberg/Mannheim, 69120, Heidelberg, Germany
| | - Norbert Frey
- Institute for Cardiomyopathies & Center for Cardiogenetics, Department of Medicine III, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Standort Heidelberg/Mannheim, 69120, Heidelberg, Germany
| | - Benjamin Meder
- Institute for Cardiomyopathies & Center for Cardiogenetics, Department of Medicine III, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany.
- DZHK (German Centre for Cardiovascular Research), Standort Heidelberg/Mannheim, 69120, Heidelberg, Germany.
- Stanford Genome Technology Center, Stanford University School of Medicine, Palo Alto, CA, 94305, USA.
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Norrish G, Kadirrajah V, Field E, Dady K, Tollit J, McLeod K, McGowan R, Cervi E, Kaski JP. Childhood Hypertrophic Cardiomyopathy Caused by Beta-Myosin Heavy Chain Variants Is Associated With a More Obstructive but Less Arrhythmogenic Phenotype Than Myosin-Binding Protein C Disease. CIRCULATION. GENOMIC AND PRECISION MEDICINE 2023; 16:483-485. [PMID: 37387224 DOI: 10.1161/circgen.123.004118] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/01/2023]
Affiliation(s)
- Gabrielle Norrish
- Centre for Inherited Cardiovascular Diseases, Great Ormond Street Hospital, London, United Kingdom (G.N., E.F., K.D., J.T., E.C., J.P.K.)
- Institute of Cardiovascular Science, University College London, United Kingdom (G.N., V.K., E.F., J.T., E.C., J.P.K.)
| | - Vidthya Kadirrajah
- Institute of Cardiovascular Science, University College London, United Kingdom (G.N., V.K., E.F., J.T., E.C., J.P.K.)
| | - Ella Field
- Centre for Inherited Cardiovascular Diseases, Great Ormond Street Hospital, London, United Kingdom (G.N., E.F., K.D., J.T., E.C., J.P.K.)
- Institute of Cardiovascular Science, University College London, United Kingdom (G.N., V.K., E.F., J.T., E.C., J.P.K.)
| | - Kathleen Dady
- Centre for Inherited Cardiovascular Diseases, Great Ormond Street Hospital, London, United Kingdom (G.N., E.F., K.D., J.T., E.C., J.P.K.)
| | - Jennifer Tollit
- Centre for Inherited Cardiovascular Diseases, Great Ormond Street Hospital, London, United Kingdom (G.N., E.F., K.D., J.T., E.C., J.P.K.)
- Institute of Cardiovascular Science, University College London, United Kingdom (G.N., V.K., E.F., J.T., E.C., J.P.K.)
| | - Karen McLeod
- Department of Pediatric Cardiology, Royal Hospital for Children, Glasgow, United Kingdom (KML)
| | - Ruth McGowan
- West of Scotland Centre for Genomic Medicine, Glasgow, United Kingdom (R.M.G.)
| | - Elena Cervi
- Centre for Inherited Cardiovascular Diseases, Great Ormond Street Hospital, London, United Kingdom (G.N., E.F., K.D., J.T., E.C., J.P.K.)
- Institute of Cardiovascular Science, University College London, United Kingdom (G.N., V.K., E.F., J.T., E.C., J.P.K.)
| | - Juan Pablo Kaski
- Centre for Inherited Cardiovascular Diseases, Great Ormond Street Hospital, London, United Kingdom (G.N., E.F., K.D., J.T., E.C., J.P.K.)
- Institute of Cardiovascular Science, University College London, United Kingdom (G.N., V.K., E.F., J.T., E.C., J.P.K.)
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Wong J, Peters S, Marwick TH. Phenotyping heart failure by genetics and associated conditions. Eur Heart J Cardiovasc Imaging 2023; 24:1293-1301. [PMID: 37279791 DOI: 10.1093/ehjci/jead125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 05/26/2023] [Indexed: 06/08/2023] Open
Abstract
Heart failure is a highly heterogeneous disease, and genetic testing may allow phenotypic distinctions that are incremental to those obtainable from imaging. Advances in genetic testing have allowed for the identification of deleterious variants in patients with specific heart failure phenotypes (dilated cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, and hypertrophic cardiomyopathy), and many of these have specific treatment implications. The diagnostic yield of genetic testing in heart failure is modest, and many rare variants are associated with incomplete penetrance and variable expressivity. Environmental factors and co-morbidities have a large role in the heterogeneity of the heart failure phenotype. Future endeavours should concentrate on the cumulative impact of genetic polymorphisms in the development of heart failure.
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Affiliation(s)
- Joshua Wong
- Baker Heart and Diabetes Institute and Department of Cardiometabolic Health, University of Melbourne, PO Box 6492, Melbourne, VIC 3004, Australia
| | - Stacey Peters
- Baker Heart and Diabetes Institute and Department of Cardiometabolic Health, University of Melbourne, PO Box 6492, Melbourne, VIC 3004, Australia
| | - Thomas H Marwick
- Baker Heart and Diabetes Institute and Department of Cardiometabolic Health, University of Melbourne, PO Box 6492, Melbourne, VIC 3004, Australia
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Santoro F, Mango F, Mallardi A, D'Alessandro D, Casavecchia G, Gravina M, Correale M, Brunetti ND. Arrhythmic Risk Stratification among Patients with Hypertrophic Cardiomyopathy. J Clin Med 2023; 12:jcm12103397. [PMID: 37240503 DOI: 10.3390/jcm12103397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 05/07/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a cardiac muscle disorder characterized by generally asymmetric abnormal hypertrophy of the left ventricle without abnormal loading conditions (such as hypertension or valvular heart disease) accounting for the left ventricular wall thickness or mass. The incidence of sudden cardiac death (SCD) in HCM patients is about 1% yearly in adults, but it is far higher in adolescence. HCM is the most frequent cause of death in athletes in the Unites States of America. HCM is an autosomal-dominant genetic cardiomyopathy, and mutations in the genes encoding sarcomeric proteins are identified in 30-60% of cases. The presence of this genetic mutation carries more than 2-fold increased risk for all outcomes, including ventricular arrhythmias. Genetic and myocardial substrate, including fibrosis and intraventricular dispersion of conduction, ventricular hypertrophy and microvascular ischemia, increased myofilament calcium sensitivity and abnormal calcium handling, all play a role as arrhythmogenic determinants. Cardiac imaging studies provide important information for risk stratification. Transthoracic echocardiography can be helpful to evaluate left ventricular (LV) wall thickness, LV outflow-tract gradient and left atrial size. Additionally, cardiac magnetic resonance can evaluate the prevalence of late gadolinium enhancement, which when higher than 15% of LV mass is a prognostic maker of SCD. Age, family history of SCD, syncope and non-sustained ventricular tachycardia at Holter ECG have also been validated as independent prognostic markers of SCD. Arrhythmic risk stratification in HCM requires careful evaluation of several clinical aspects. Symptoms combined with electrocardiogram, cardiac imaging tools and genetic counselling are the modern cornerstone for proper risk stratification.
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Affiliation(s)
- Francesco Santoro
- Cardiology Unit, Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy
| | - Federica Mango
- Cardiology Unit, Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy
| | - Adriana Mallardi
- Cardiology Unit, Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy
| | - Damiano D'Alessandro
- Cardiology Unit, Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy
| | - Grazia Casavecchia
- Cardiology Unit, Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy
| | - Matteo Gravina
- Radiology Unit, University Polyclinic Hospital of Foggia, 71100 Foggia, Italy
| | - Michele Correale
- Cardiology Unit, Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy
| | - Natale Daniele Brunetti
- Cardiology Unit, Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy
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Fernández Suárez N, Viadero Ubierna MT, Garde Basas J, Onecha de la Fuente ME, Amigo Lanza MT, Martin Gorria G, Rivas Pérez A, Ruiz Guerrero L, González-Lamuño D. Description of a Cohort with a New Truncating MYBPC3 Variant for Hypertrophic Cardiomyopathy in Northern Spain. Genes (Basel) 2023; 14:genes14040840. [PMID: 37107598 PMCID: PMC10137663 DOI: 10.3390/genes14040840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/21/2023] [Accepted: 03/24/2023] [Indexed: 04/03/2023] Open
Abstract
Background: The pathogenicity of the different genetic variants causing hypertrophic cardiomyopathy (HCM) and the genotype/phenotype correlations are difficult to assess in clinical practice, as most mutations are unique or identified in non-informative families. Pathogenic variants in the sarcomeric gene MYBPC3 inherited with an autosomal dominant pattern, whereas incomplete and age-dependent penetrance are the most common causes of HCM. Methods: We describe the clinical characteristics of a new truncating MYBPC3 variant, p.Val931Glyfs*120, in 75 subjects from 18 different families from northern Spain with the p.Val931Glyfs*120 variant. Results: Our cohort allows us to estimate the penetrance and prognosis of this variant. The penetrance of the disease increases with age, whereas 50% of males in our sample developed HCM by the age of 36 years old, and 50% of women developed the disease by the time they reached 48 years of age (p = 0.104). Men have more documented arrhythmias with potential risk of sudden death (p = 0.018), requiring implantation of cardioverter defibrillators (p = 0.024). Semi-professional/competitive sport among males is related to earlier onset of HCM (p = 0.004). Conclusions: The p.Val931Glyfs*120 truncating variant in MYBPC3 is associated with a moderate phenotype of HCM, with a high penetrance, onset in middle age, and a worse outcome in males due to higher risk of sudden death due to arrhythmias.
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Identification of Two Homozygous Variants in MYBPC3 and SMYD1 Genes Associated with Severe Infantile Cardiomyopathy. Genes (Basel) 2023; 14:genes14030659. [PMID: 36980931 PMCID: PMC10048717 DOI: 10.3390/genes14030659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 02/15/2023] [Accepted: 02/28/2023] [Indexed: 03/08/2023] Open
Abstract
Mutations in cardiac genes are one of the primary causes of infantile cardiomyopathy. In this study, we report the genetic findings of two siblings carrying variations in the MYBPC3 and SMYD1 genes. The first patient is a female proband exhibiting hypertrophic cardiomyopathy (HCM) and biventricular heart failure carrying a truncating homozygous MYBPC3 variant c.1224-52G>A (IVS13-52G>A) and a novel homozygous variant (c.302A>G; p.Asn101Ser) in the SMYD1 gene. The second patient, the proband’s sibling, is a male infant diagnosed with hypertrophic cardiomyopathy and carries the same homozygous MYBPC3 variant. While this specific MYBPC3 variant (c.1224-52G>A, IVS13-52G>A) has been previously reported to be associated with adult-onset hypertrophic cardiomyopathy, this is the first report linking it to infantile cardiomyopathy. In addition, this work describes, for the first time, a novel SMYD1 variant (c.302A>G; p.Asn101Ser) that has never been reported. We performed a histopathological evaluation of tissues collected from both probands and show that these variants lead to myofibrillar disarray, reduced and irregular mitochondrial cristae and cardiac fibrosis. Together, these results provide critical insight into the molecular functionality of these genes in human cardiac physiology.
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Field E, Norrish G, Acquaah V, Dady K, Cicerchia MN, Ochoa JP, Syrris P, McLeod K, McGowan R, Fell H, Lopes LR, Cervi E, Kaski JPP. Cardiac myosin binding protein-C variants in paediatric-onset hypertrophic cardiomyopathy: natural history and clinical outcomes. J Med Genet 2022; 59:768-775. [PMID: 34400558 PMCID: PMC7613139 DOI: 10.1136/jmedgenet-2021-107774] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 07/14/2021] [Indexed: 02/03/2023]
Abstract
BACKGROUND Variants in the cardiac myosin-binding protein C gene (MYBPC3) are a common cause of hypertrophic cardiomyopathy (HCM) in adults and have been associated with late-onset disease, but there are limited data on their role in paediatric-onset HCM. The objective of this study was to describe natural history and clinical outcomes in a large cohort of children with HCM and pathogenic/likely pathogenic (P/LP) MYBPC3 variants. METHODS AND RESULTS Longitudinal data from 62 consecutive patients diagnosed with HCM under 18 years of age and carrying at least one P/LP MYBPC3 variant were collected from a single specialist referral centre. The primary patient outcome was a major adverse cardiac event (MACE). Median age at diagnosis was 10 (IQR: 2-14) years, with 12 patients (19.4%) diagnosed in infancy. Forty-seven (75%) were boy and 31 (50%) were probands. Median length of follow-up was 3.1 (IQR: 1.6-6.9) years. Nine patients (14.5%) experienced an MACE during follow-up and five (8%) died. Twenty patients (32.3%) had evidence of ventricular arrhythmia, including 6 patients (9.7%) presenting with out-of-hospital cardiac arrest. Five-year freedom from MACE for those with a single or two MYBPC3 variants was 95.2% (95% CI: 78.6% to 98.5%) and 68.4% (95% CI: 40.6% to 88.9%), respectively (HR 4.65, 95% CI: 1.16 to 18.66, p=0.03). CONCLUSIONS MYBPC3 variants can cause childhood-onset disease, which is frequently associated with life-threatening ventricular arrhythmia. Clinical outcomes in this cohort vary substantially from aetiologically and genetically mixed paediatric HCM cohorts described previously, highlighting the importance of identifying specific genetic subtypes for clinical management of childhood HCM.
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Affiliation(s)
- Ella Field
- Centre for Inherited Cardiovascular Diseases, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
- Institute of Cardiovascular Science, University College London, London, UK
| | - Gabrielle Norrish
- Centre for Inherited Cardiovascular Diseases, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
- Institute of Cardiovascular Science, University College London, London, UK
| | - Vanessa Acquaah
- Institute of Cardiovascular Science, University College London, London, UK
| | - Kathleen Dady
- Centre for Inherited Cardiovascular Diseases, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
- Institute of Cardiovascular Science, University College London, London, UK
| | | | | | - Petros Syrris
- Institute of Cardiovascular Science, University College London, London, UK
| | - Karen McLeod
- Department of Paediatric Cardiology, Royal Hospital for Children, Glasgow, UK
| | - Ruth McGowan
- West of Scotland Centre for Genomic Medicine, Glasgow, UK
| | - Hannah Fell
- Centre for Inherited Cardiovascular Diseases, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Luis R Lopes
- Institute of Cardiovascular Science, University College London, London, UK
- Inherited Cardiovascular Disease Unit, Saint Bartholomew's Hospital Barts Heart Centre, London, UK
| | - Elena Cervi
- Centre for Inherited Cardiovascular Diseases, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
- Institute of Cardiovascular Science, University College London, London, UK
| | - Juan Pablo Pablo Kaski
- Centre for Inherited Cardiovascular Diseases, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
- Institute of Cardiovascular Science, University College London, London, UK
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Lin LR, Hu XQ, Lu LH, Dai JZ, Lin NN, Wang RH, Xie ZX, Chen XM. MicroRNA expression profiles in familial hypertrophic cardiomyopathy with myosin-binding protein C3 (MYBPC3) gene mutations. BMC Cardiovasc Disord 2022; 22:278. [PMID: 35717150 PMCID: PMC9206743 DOI: 10.1186/s12872-022-02714-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 06/08/2022] [Indexed: 11/30/2022] Open
Abstract
Familial hypertrophic cardiomyopathy (FHCM) is an autosomal dominant inherited disease caused by mutations in genes encoding cardiac sarcomere proteins. MicroRNAs (miRNAs) play an important role in the pathogenesis of FHCM. In the present study, we aimed to determine the miRNA profile in FHCM patients with myosin-binding protein C3 (MYBPC3) gene mutations. We recruited three FHCM patients and age- and sex-matched controls. The three probands all had hypertrophic obstructive cardiomyopathy with severe myocardial hypertrophy, and two of the three had a history of sudden cardiac death, representing a “malignant” phenotype. We then compared the miRNA expression profiles of three FHCM patients carrying MYBPC3 gene mutations with those of the normal control group using miRNA sequencing technology. Differentially expressed miRNAs were verified using real-time polymerase chain reaction (qPCR). Target genes and signaling pathways of the identified differentially expressed miRNAs were predicted using bioinformatics analysis. A total of 33 significantly differentially expressed miRNAs were detected in the peripheral blood of the three probands, of which 28 were upregulated, including miR-208b-3p, and 5 were downregulated. Real-time PCR confirmed the upregulated expression of miR-208b-3p in FHCM patients (P < 0.05). Bioinformatics analysis showed that miR-208b-3p was mainly enriched in 79 target genes including UBE2V2, MED13, YBX1, CNKSR2, GATA4, andSOX5/6, et al. Gene ontology (GO) analysis of target genes showed that miR-208b was mainly involved in the processes of negative regulation of transcription from RNA polymerase II promoter, and regulation of transcription, DNA templated. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that the target genes regulated by miR-208b-3p were mainly involved in the Wnt signaling pathway. These findings suggest that FHCM patients with MYBPC3 gene mutations have a specific miRNA expression profile, and that miR-208b-3p is significantly upregulated in cardiac hypertrophy. Our results also indicate that miRNA-208b-3p activates the Wnt signaling pathway through its target gene to promote cardiac hypertrophy.
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Affiliation(s)
- Li-Rong Lin
- Shengli Clinical Medical College of Fujian Medical University, Fuzhou, 350001, China.,Department of Cardiology, Fujian Provincial Hospital, Fuzhou, 350001, China
| | - Xue-Qun Hu
- Shengli Clinical Medical College of Fujian Medical University, Fuzhou, 350001, China.,Department of Neurosurgery, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350001, China
| | - Li-Hong Lu
- Shengli Clinical Medical College of Fujian Medical University, Fuzhou, 350001, China. .,Department of Cardiology, Fujian Provincial Hospital, Fuzhou, 350001, China.
| | - Jia-Zhen Dai
- Shengli Clinical Medical College of Fujian Medical University, Fuzhou, 350001, China
| | - Ning-Ning Lin
- Shengli Clinical Medical College of Fujian Medical University, Fuzhou, 350001, China
| | - Re-Hua Wang
- Shengli Clinical Medical College of Fujian Medical University, Fuzhou, 350001, China.,Department of Cardiology, Fujian Provincial Hospital, Fuzhou, 350001, China
| | - Zhang-Xin Xie
- Shengli Clinical Medical College of Fujian Medical University, Fuzhou, 350001, China.,Department of Emergency, Fujian Provincial Hospital, Fuzhou, 350001, China
| | - Xue-Mei Chen
- Shengli Clinical Medical College of Fujian Medical University, Fuzhou, 350001, China.,Department of Cardiology, Fujian Provincial Hospital, Fuzhou, 350001, China
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10
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A Novel Loss-of-function Mutation in MYBPC3 Causes Familial Hypertrophic Cardiomyopathy with Extreme Intrafamilial Phenotypic Heterogeneity. Balkan J Med Genet 2022; 25:71-78. [PMID: 36880031 PMCID: PMC9985356 DOI: 10.2478/bjmg-2022-0002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023] Open
Abstract
Cardiomyopathies are a heterogeneous group of diseases predominantly affecting the heart muscle and often lead to progressive heart failure-related disability or cardiovascular death. Hypertrophic cardiomyopathy (HCM) is a cardiac muscle disorder mostly caused by the mutations in genes encoding cardiac sarcomere. Germ-line mutations in MYBPC3 causes hypertrophic cardiomyopathy (HCM). However, most of the HCM associated MYBPC3 mutations were truncating mutations. Extreme phenotypic heterogeneity was observed among HCM patients with MYBPC3 mutations. In this study, we investigated a Chinese man who presented with HCM. Whole exome sequencing identified a novel heterozygous deletion (c.3781_3785delGAGGC) in exon 33 of the MYBPC3 in the proband. This heterozygous variant causes frameshift (p.Glu1261Thrfs*3), which predicted to form a truncated MYBPC3 protein. The proband's father also carries this variant in a heterozygous state while the proband's mother did not harbor this variant. Here, we report on a novel deletion in the MYBPC3 gene associated with HCM. We also highlight the importance of whole exome sequencing for molecular diagnosis for the patients with familial HCM.
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11
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Suay-Corredera C, Alegre-Cebollada J. The mechanics of the heart: zooming in on hypertrophic cardiomyopathy and cMyBP-C. FEBS Lett 2022; 596:703-746. [PMID: 35224729 DOI: 10.1002/1873-3468.14301] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 01/10/2022] [Accepted: 01/14/2022] [Indexed: 11/10/2022]
Abstract
Hypertrophic cardiomyopathy (HCM), a disease characterized by cardiac muscle hypertrophy and hypercontractility, is the most frequently inherited disorder of the heart. HCM is mainly caused by variants in genes encoding proteins of the sarcomere, the basic contractile unit of cardiomyocytes. The most frequently mutated among them is MYBPC3, which encodes cardiac myosin-binding protein C (cMyBP-C), a key regulator of sarcomere contraction. In this review, we summarize clinical and genetic aspects of HCM and provide updated information on the function of the healthy and HCM sarcomere, as well as on emerging therapeutic options targeting sarcomere mechanical activity. Building on what is known about cMyBP-C activity, we examine different pathogenicity drivers by which MYBPC3 variants can cause disease, focussing on protein haploinsufficiency as a common pathomechanism also in nontruncating variants. Finally, we discuss recent evidence correlating altered cMyBP-C mechanical properties with HCM development.
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12
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Vriz O, AlSergani H, Elshaer AN, Shaik A, Mushtaq AH, Lioncino M, Alamro B, Monda E, Caiazza M, Mauro C, Bossone E, Al-Hassnan ZN, Albert-Brotons D, Limongelli G. A complex unit for a complex disease: the HCM-Family Unit. Monaldi Arch Chest Dis 2021; 92. [PMID: 34964577 DOI: 10.4081/monaldi.2021.2147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 11/30/2021] [Indexed: 11/23/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a group of heterogeneous disorders that are most commonly passed on in a heritable manner. It is a relatively rare disease around the globe, but due to increased rates of consanguinity within the Kingdom of Saudi Arabia, we speculate a high incidence of undiagnosed cases. The aim of this paper is to elucidate a systematic approach in dealing with HCM patients and since HCM has variable presentation, we have summarized differentials for diagnosis and how different subtypes and genes can have an impact on the clinical picture, management and prognosis. Moreover, we propose a referral multi-disciplinary team HCM-Family Unit in Saudi Arabia and an integrated role in a network between King Faisal Hospital and Inherited and Rare Cardiovascular Disease Unit-Monaldi Hospital, Italy (among the 24 excellence centers of the European Reference Network (ERN) GUARD-Heart). Graphical Abstract.
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Affiliation(s)
- Olga Vriz
- Department of Cardiology, King Faisal Specialist Hospital and Research Center, Riyadh.
| | - Hani AlSergani
- Department of Cardiology, King Faisal Specialist Hospital and Research Center, Riyadh.
| | | | | | | | - Michele Lioncino
- Inherited and Rare Cardiovascular Disease Unit, Department of Translational Medical Sciences, University of Campania "Luigi Vanvitelli", AORN dei Colli, Monaldi Hospital, Naples.
| | - Bandar Alamro
- Department of Cardiology, King Faisal Specialist Hospital and Research Center, Riyadh.
| | - Emanuele Monda
- Inherited and Rare Cardiovascular Disease Unit, Department of Translational Medical Sciences, University of Campania "Luigi Vanvitelli", AORN dei Colli, Monaldi Hospital, Naples.
| | - Martina Caiazza
- Inherited and Rare Cardiovascular Disease Unit, Department of Translational Medical Sciences, University of Campania "Luigi Vanvitelli", AORN dei Colli, Monaldi Hospital, Naples.
| | - Ciro Mauro
- Department of Cardiology, Cardarelli Hospital, Naples.
| | | | - Zuhair N Al-Hassnan
- Cardiovascular Genetics Program and Department of Medical Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh.
| | - Dimpna Albert-Brotons
- Department of Cardiology, King Faisal Specialist Hospital and Research Center, Riyadh.
| | - Giuseppe Limongelli
- Inherited and Rare Cardiovascular Disease Unit, Department of Translational Medical Sciences, University of Campania "Luigi Vanvitelli", AORN dei Colli, Monaldi Hospital, Naples.
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13
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Kim KH, Pereira NL. Genetics of Cardiomyopathy: Clinical and Mechanistic Implications for Heart Failure. Korean Circ J 2021; 51:797-836. [PMID: 34327881 PMCID: PMC8484993 DOI: 10.4070/kcj.2021.0154] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 06/14/2021] [Indexed: 11/11/2022] Open
Abstract
Genetic cardiomyopathies are an important cause of sudden cardiac death across all age groups. Genetic testing in heart failure clinics is useful for family screening and providing individual prognostic insight. Obtaining a family history of at least three generations, including the creation of a pedigree, is recommended for all patients with primary cardiomyopathy. Additionally, when appropriate, consultation with a genetic counsellor can aid in the success of a genetic evaluation. Clinical screening should be performed on all first-degree relatives of patients with genetic cardiomyopathy. Genetics has played an important role in the understanding of different cardiomyopathies, and the field of heart failure (HF) genetics is progressing rapidly. Much research has also focused on distinguishing markers of risk in patients with cardiomyopathy using genetic testing. While these efforts currently remain incomplete, new genomic technologies and analytical strategies provide promising opportunities to further explore the genetic architecture of cardiomyopathies, afford insight into the early manifestations of cardiomyopathy, and help define the molecular pathophysiological basis for cardiac remodeling. Cardiovascular physicians should be fully aware of the utility and potential pitfalls of incorporating genetic test results into pre-emptive treatment strategies for patients in the preliminary stages of HF. Future work will need to be directed towards elucidating the biological mechanisms of both rare and common gene variants and environmental determinants of plasticity in the genotype-phenotype relationship. This future research should aim to further our ability to identify, diagnose, and treat disorders that cause HF and sudden cardiac death in young patients, as well as prioritize improving our ability to stratify the risk for these patients prior to the onset of the more severe consequences of their disease.
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Affiliation(s)
- Kyung Hee Kim
- Division of Cardiology, Incheon Sejong General Hospital, Incheon, Korea.
| | - Naveen L Pereira
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA.,Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
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14
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Baudry G, Mansencal N, Reynaud A, Richard P, Dubourg O, Komajda M, Isnard R, Réant P, Charron P. Global and regional echocardiographic strain to assess the early phase of hypertrophic cardiomyopathy due to sarcomeric mutations. Eur Heart J Cardiovasc Imaging 2021; 21:291-298. [PMID: 31056691 DOI: 10.1093/ehjci/jez084] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 04/01/2019] [Accepted: 04/09/2019] [Indexed: 01/24/2023] Open
Abstract
AIMS Hypertrophic cardiomyopathy (HCM) is a genetic disease with delayed cardiac expression. Our objective was to characterize left ventricular (LV) myocardial strain by two-dimensional echocardiography in sarcomeric mutation carriers before the hypertrophic stage. METHODS AND RESULTS We studied 140 adults [derivation cohort (n = 79), validation cohort (n = 61)]. The derivation cohort comprised 38 confirmed HCM patients with hypertrophy (LVH+/Gen+), 20 mutation carriers without LV hypertrophy (LVH-/Gen+), and 21 healthy controls. LV global longitudinal strain was not different in LVH-/Gen+ compared with controls [20.6%, interquartile (IQ): 18.3/24.2 vs. 22.9%, IQ: 20.9/26.8] but was reduced in LVH+/Gen+ patients (14.1%, IQ: 11.8/18.5, P < 0.001). Regional peak longitudinal strain was significantly decreased in LVH-/Gen+ when compared with controls in four segments: basal anteroseptal (BAS) wall (P = 0.018), basal inferoseptal wall (P = 0.047), basal inferior wall (P = 0.006), and mid anteroseptal wall (P = 0.022). Receiver operating characteristic analysis identified that BAS strain <16.5% had a sensitivity (Se), specificity (Sp), positive and negative predictive values (PPV, NPV) of 57%, 90%, 82%, and 67%, respectively, to differentiate LVH-/G+ patients from controls. Similarly, the accuracy of a ratio between basal inferoseptal/basal anterolateral (BIS/BAL) strain <0.76 was 73%, 92%, 82%, and 64%, respectively (Se/Sp/PPV/NPV). In the validation cohort, the accuracy of BAS and BIS/BAL was 39%/93%/87%/57% and 55%/96%/95%/64% (Se/Sp/PPV/NPV), respectively, to differentiate the LVH-/Gen+ group from controls. CONCLUSION Regional longitudinal strain, but not global strain, was significantly reduced at the early stage of HCM before LV hypertrophy. This suggests that the inclusion of strain (BAS < 16.5%; BIS/BAL < 0.76) in the evaluation of HCM relatives would help identify mutation carriers and early LV abnormalities.
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Affiliation(s)
- Guillaume Baudry
- APHP, Centre de référence pour les maladies cardiaques héréditaires, Hôpital Pitié-Salpêtrière, 47 bvd de l'hôpital, 75013 Paris, France.,HCL, Service Insuffisance cardiaque, Hôpital Louis Pradel, 59 Boulevard Pinel, 69500 Bron, France
| | - Nicolas Mansencal
- APHP, Service de Cardiologie, CHU Ambroise Paré, 9 av Charles de Gaulle, 92100 Boulogne Billancourt, France.,INSERM U-1018, CESP, Team 5 (EpReC, Renal and Cardiovascular Epidemiology), UVSQ, 94800 Villejuif, France
| | - Amelie Reynaud
- Université de Bordeaux, CHU de Bordeaux, Service de cardiologie, Bordeaux, 33600 Pessac, France
| | - Pascale Richard
- APHP, UF Cardiogénétique et Myogénétique, Service de Biochimie Métabolique, Hôpitaux Universitaires de la Pitié-Salpêtrière-Charles Foix, 47 Bvd de l'Hôpital, 75013 Paris, France
| | - Olivier Dubourg
- APHP, Service de Cardiologie, CHU Ambroise Paré, 9 av Charles de Gaulle, 92100 Boulogne Billancourt, France.,INSERM U-1018, CESP, Team 5 (EpReC, Renal and Cardiovascular Epidemiology), UVSQ, 94800 Villejuif, France
| | - Michel Komajda
- APHP, Centre de référence pour les maladies cardiaques héréditaires, Hôpital Pitié-Salpêtrière, 47 bvd de l'hôpital, 75013 Paris, France.,Service de Cardiologie, Hôpital Saint Joseph, 75014 Paris, France
| | - Richard Isnard
- APHP, Centre de référence pour les maladies cardiaques héréditaires, Hôpital Pitié-Salpêtrière, 47 bvd de l'hôpital, 75013 Paris, France.,Sorbonne Université, INSERM, UMR_S 1166 and ICAN Institute for Cardiometabolism and Nutrition, 91 bvd de l'hôpital, 75013 Paris, France
| | - Patricia Réant
- Université de Bordeaux, CHU de Bordeaux, Service de cardiologie, Bordeaux, 33600 Pessac, France
| | - Philippe Charron
- APHP, Centre de référence pour les maladies cardiaques héréditaires, Hôpital Pitié-Salpêtrière, 47 bvd de l'hôpital, 75013 Paris, France.,Sorbonne Université, INSERM, UMR_S 1166 and ICAN Institute for Cardiometabolism and Nutrition, 91 bvd de l'hôpital, 75013 Paris, France
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15
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Robyns T, Breckpot J, Nuyens D, Vandenberk B, Corveleyn A, Kuiperi C, Van Aelst L, Van Cleemput J, Willems R. Clinical and ECG variables to predict the outcome of genetic testing in hypertrophic cardiomyopathy. Eur J Med Genet 2020; 63:103754. [DOI: 10.1016/j.ejmg.2019.103754] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 08/23/2019] [Accepted: 09/08/2019] [Indexed: 10/26/2022]
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Abstract
BACKGROUND Hypertrophic cardiomyopathy is an autosomal dominant hereditary disease characterised by left ventricular asymmetry hypertrophy. However, our knowledge of the genetic background in hypertrophic cardiomyopathy cases is limited. Here, we aimed to evaluate pathogenic gene mutations in a family with high-risk hypertrophic cardiomyopathy and analyse the genotype/phenotype relationships in this family. METHODS The proband, her parents, and her niece underwent whole-exome sequencing, and the genotypes of family members were identified using Sanger sequencing. mRNA expression was detected using reverse transcription sequencing. Structural impairments were predicted by homologous modelling. A family survey was conducted for patients with positive results to obtain information on general clinical symptoms, electrocardiography, ambulatory electrocardiography, echocardiography, and 3.0T cardiac magnetic resonance findings. Regular follow-up was performed for up to 6 months. RESULTS Five family members, including the proband, carried a cleavage site mutation in the MYBPC3 gene (c.2737+1 (IVS26) G>T), causing exon 26 of the MYBPC3 gene transcript to be skipped and leading to truncation of cardiac myosin-binding protein C. Family survey showed that the earliest onset age was 13 years old, and three people had died suddenly at less than 40 years old. Three pathogenic gene carriers were diagnosed with hypertrophic cardiomyopathy, and all showed severe ventricular septal hypertrophy. CONCLUSION The c.2737+1 (IVS26) G>T mutation in the MYBPC3 gene led to exon 26 skipping, thereby affecting the structure and function of cardiac myosin-binding protein C and leading to severe ventricular hypertrophy and sudden death.
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17
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Spudich JA. Three perspectives on the molecular basis of hypercontractility caused by hypertrophic cardiomyopathy mutations. Pflugers Arch 2019; 471:701-717. [PMID: 30767072 PMCID: PMC6475635 DOI: 10.1007/s00424-019-02259-2] [Citation(s) in RCA: 91] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 01/11/2019] [Accepted: 01/20/2019] [Indexed: 01/10/2023]
Abstract
Several lines of evidence suggest that the primary effect of hypertrophic cardiomyopathy mutations in human β-cardiac myosin is hypercontractility of the heart, which leads to subsequent hypertrophy, fibrosis, and myofilament disarray. Here, I describe three perspectives on the molecular basis of this hypercontractility. The first is that hypercontractility results from changes in the fundamental parameters of the actin-activated β-cardiac myosin chemo-mechanical ATPase cycle. The second considers that hypercontractility results from an increase in the number of functionally accessible heads in the sarcomere for interaction with actin. The final and third perspective is that load dependence of contractility is affected by cardiomyopathy mutations and small-molecule effectors in a manner that changes the power output of cardiac contraction. Experimental approaches associated with each perspective are described along with concepts of therapeutic approaches that could prove valuable in treating hypertrophic cardiomyopathy.
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Affiliation(s)
- James A Spudich
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, 94305, USA.
- Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, 94305, USA.
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18
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Hata Y, Ichimata S, Yamaguchi Y, Hirono K, Oku Y, Ichida F, Nishida N. Clinicopathological and Genetic Profiles of Cases with Myocytes Disarray-Investigation for Establishing the Autopsy Diagnostic Criteria for Hypertrophic Cardiomyopathy. J Clin Med 2019; 8:jcm8040463. [PMID: 30959811 PMCID: PMC6518201 DOI: 10.3390/jcm8040463] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 03/31/2019] [Accepted: 04/01/2019] [Indexed: 02/06/2023] Open
Abstract
Myocyte disarray of >10% in the heart is broadly accepted as a diagnostic pitfall for hypertrophic cardiomyopathy (HCM) at postmortem. The present study aims to propose an additional diagnostic criterion of HCM. Heart specimens from 1387 serial forensic autopsy cases were examined. Cases with myocyte disarray were extracted and applied to morphometric analysis to determine the amount of myocyte disarray. Comprehensive genetic analysis by using next-generation sequencing was subsequently applied for cases with myocyte disarray. Fifteen cases with myocyte disarray were extracted as candidate cases (1.1%, 11 men and 4 women, aged 48–94 years). In terms of the cause of death, only 2 cases were cardiac or possible cardiac death, and the other was non-cardiac death. Six cases showed myocyte disarray of >10% and 3 cases showed myocyte disarray of 5% to 10%. The other 6 cases showed myocyte disarray of <5%. Nine rare variants in 5 HCM-related genes (MYBPC3, MYH7, MYH6, PRKAG2, and CAV3) were found in 8 of 9 cases with myocyte disarray of >5%. The remaining 1 and 6 cases with myocyte disarray of <5% did not have any such variant. Myocyte disarray of >5% with rare variants in related genes might be an appropriate postmortem diagnostic criterion for HCM, in addition to myocyte disarray of 10%.
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Affiliation(s)
- Yukiko Hata
- Department of Legal Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan.
| | - Shojiro Ichimata
- Department of Legal Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan.
| | - Yoshiaki Yamaguchi
- Second Department of Internal Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan.
| | - Keiichi Hirono
- Department of Pediatrics, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan.
| | - Yuko Oku
- Department of Legal Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan.
| | - Fukiko Ichida
- Department of Pediatrics, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan.
| | - Naoki Nishida
- Department of Legal Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan.
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19
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Viswanathan SK, Sanders HK, McNamara JW, Jagadeesan A, Jahangir A, Tajik AJ, Sadayappan S. Hypertrophic cardiomyopathy clinical phenotype is independent of gene mutation and mutation dosage. PLoS One 2017; 12:e0187948. [PMID: 29121657 PMCID: PMC5679632 DOI: 10.1371/journal.pone.0187948] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 10/27/2017] [Indexed: 12/27/2022] Open
Abstract
Over 1,500 gene mutations are known to cause hypertrophic cardiomyopathy (HCM). Previous studies suggest that cardiac β-myosin heavy chain (MYH7) gene mutations are commonly associated with a more severe phenotype, compared to cardiac myosin binding protein-C (MYBPC3) gene mutations with milder phenotype, incomplete penetrance and later age of onset. Compound mutations can worsen the phenotype. This study aimed to validate these comparative differences in a large cohort of individuals and families with HCM. We performed genome-phenome correlation among 80 symptomatic HCM patients, 35 asymptomatic carriers and 35 non-carriers, using an 18-gene clinical diagnostic HCM panel. A total of 125 mutations were identified in 14 genes. MYBPC3 and MYH7 mutations contributed to 50.0% and 24.4% of the HCM patients, respectively, suggesting that MYBPC3 mutations were the most frequent cause of HCM in our cohort. Double mutations were found in only nine HCM patients (7.8%) who were phenotypically indistinguishable from single-mutation carriers. Comparisons of clinical parameters of MYBPC3 and MYH7 mutants were not statistically significant, but asymptomatic carriers had high left ventricular ejection fraction and diastolic dysfunction when compared to non-carriers. The presence of double mutations increases the risk for symptomatic HCM with no change in severity, as determined in this study subset. The pathologic effects of MYBPC3 and MYH7 were found to be independent of gene mutation location. Furthermore, HCM pathology is independent of protein domain disruption in both MYBPC3 and MYH7. These data provide evidence that MYBPC3 mutations constitute the preeminent cause of HCM and that they are phenotypically indistinguishable from HCM caused by MYH7 mutations.
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Affiliation(s)
- Shiv Kumar Viswanathan
- Heart Lung Vascular Institute, Division of Cardiology, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, United States of America
- Department of Cell and Molecular Physiology, Center for Translational Research and Education, Health Sciences Division, Loyola University Chicago, Maywood, Illinois, United States of America
| | - Heather K. Sanders
- Aurora Cardiovascular Services, St. Luke’s Medical Center, Milwaukee, Wisconsin, United States of America
- Center for Integrative Research on Cardiovascular Aging (CIRCA), Aurora Health Care, Milwaukee, Wisconsin, United States of America
| | - James W. McNamara
- Heart Lung Vascular Institute, Division of Cardiology, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, United States of America
- Department of Cell and Molecular Physiology, Center for Translational Research and Education, Health Sciences Division, Loyola University Chicago, Maywood, Illinois, United States of America
| | - Aravindakshan Jagadeesan
- Department of Cell and Molecular Physiology, Center for Translational Research and Education, Health Sciences Division, Loyola University Chicago, Maywood, Illinois, United States of America
| | - Arshad Jahangir
- Aurora Cardiovascular Services, St. Luke’s Medical Center, Milwaukee, Wisconsin, United States of America
- Center for Integrative Research on Cardiovascular Aging (CIRCA), Aurora Health Care, Milwaukee, Wisconsin, United States of America
| | - A. Jamil Tajik
- Aurora Cardiovascular Services, St. Luke’s Medical Center, Milwaukee, Wisconsin, United States of America
- Center for Integrative Research on Cardiovascular Aging (CIRCA), Aurora Health Care, Milwaukee, Wisconsin, United States of America
| | - Sakthivel Sadayappan
- Heart Lung Vascular Institute, Division of Cardiology, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, United States of America
- Department of Cell and Molecular Physiology, Center for Translational Research and Education, Health Sciences Division, Loyola University Chicago, Maywood, Illinois, United States of America
- * E-mail:
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20
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Veselka J, Anavekar NS, Charron P. Hypertrophic obstructive cardiomyopathy. Lancet 2017; 389:1253-1267. [PMID: 27912983 DOI: 10.1016/s0140-6736(16)31321-6] [Citation(s) in RCA: 166] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 07/22/2016] [Accepted: 08/02/2016] [Indexed: 12/23/2022]
Abstract
Hypertrophic obstructive cardiomyopathy is an inherited myocardial disease defined by cardiac hypertrophy (wall thickness ≥15 mm) that is not explained by abnormal loading conditions, and left ventricular obstruction greater than or equal to 30 mm Hg. Typical symptoms include dyspnoea, chest pain, palpitations, and syncope. The diagnosis is usually suspected on clinical examination and confirmed by imaging. Some patients are at increased risk of sudden cardiac death, heart failure, and atrial fibrillation. Patients with an increased risk of sudden cardiac death undergo cardioverter-defibrillator implantation; in patients with severe symptoms related to ventricular obstruction, septal reduction therapy (myectomy or alcohol septal ablation) is recommended. Life-long anticoagulation is indicated after the first episode of atrial fibrillation.
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Affiliation(s)
- Josef Veselka
- Department of Cardiology, 2nd Medical School, Charles University and Motol University Hospital, Prague, Czech Republic.
| | - Nandan S Anavekar
- Departments of Cardiology and Radiology, Mayo Clinic, Rochester, MN, USA
| | - Philippe Charron
- Université Paris Sud, UVSQ, INSERM U1018, CESP, Boulogne-Billancourt, France; APHP, ICAN, Hôpital de la Pitié Salpêtrière, Paris, France
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Aurensanz Clemente E, Ayerza Casas A, García Lasheras C, Ramos Fuentes F, Bueno Martínez I, Pelegrín Díaz J, Ruiz Frontera P, Montserrat Iglesias L. Familial hypertrophic cardiomyopathy associated with a new mutation in gene MYBPC3. Clin Case Rep 2017; 5:232-237. [PMID: 28265379 PMCID: PMC5331257 DOI: 10.1002/ccr3.832] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 12/05/2016] [Accepted: 12/09/2016] [Indexed: 11/18/2022] Open
Abstract
We think that the main interests of this study are the report of a new mutation in gene MYBPC3 as a cause of Hypertrophic cardiomyopathy (HMC), and the verification of the fact that not always is the number of mutations related to the severity of the disease.
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Usefulness of Genetic Testing in Hypertrophic Cardiomyopathy: an Analysis Using Real-World Data. J Cardiovasc Transl Res 2017; 10:35-46. [PMID: 28138913 DOI: 10.1007/s12265-017-9730-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 01/15/2017] [Indexed: 10/20/2022]
Abstract
This study sought to determine the usefulness of genetic testing to predict evolution in hypertrophic cardiomyopathy (HCM) and to assess the role of genetic testing in clinical practice. Genetic results of 100 HCM patients tested for mutations in ≥10 HCM-causing genes were evaluated. Patients were classified as with poor (group A) or favourable (group B) clinical course. Forty-five pathogenic mutations (PM) were identified in 28 patients (56 %) from group A and in 23 (46 %) from group B (p = 0.317). Only 40 patients (40 %) exhibited PM that had been previously reported and only 15 (15 %) had PM reported in ≥10 individuals. PM associated with poor prognosis were identified in just five patients from group A (10 %). Genetic findings are not useful to predict prognosis in most HCM patients. By contrast, real-world data reinforce the usefulness of genetic testing to provide genetic counselling and to enable cascade genetic screening.
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McTaggart DR, Ogden KJ, Marathe JA. A Long Term Follow-up Study of Carriers of Hypertrophic Cardiomyopathy Mutations. Heart Lung Circ 2016; 26:18-24. [PMID: 27373729 DOI: 10.1016/j.hlc.2016.04.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 03/24/2016] [Accepted: 04/10/2016] [Indexed: 10/21/2022]
Abstract
BACKGROUND Adults who test positive for a mutation associated with the development of hypertrophic cardiomyopathy (HCM) but who have not manifested left ventricular hypertrophy (LVH) at the time of that diagnosis are now commonly identified in the era of genetic testing. There are little published data, however, on the long-term outlook for these phenotypically normal gene carriers. METHODS Fifteen genotype positive/LVH negative patients with HCM were identified, seven of which were children when first diagnosed as gene carriers. Fourteen were followed up with clinical examinations, electrocardiography and echocardiography to determine if their clinical status had changed over time. Measurements included electrocardiographic changes, changes in wall thickness, diastolic function and global longitudinal stain. RESULTS Ten participants were followed up for a total of 18 years, two for a total of 17 years, one for 11 years and one for 8 years. In addition, magnetic resonance imaging (MRI) studies were performed on 11 participants. Eleven participants carried a mutation for the MYBPC3 gene and three carried a mutation for the MYH7 gene. One patient, an adult at the time of initial investigation, developed phenotypic features of HCM on echocardiography and MRI, one an increase in wall thickness diagnostic for HCM only on MRI and another to be borderline for HCM on MRI. CONCLUSION Hypertrophic cardiomyopathy can develop in adult life in carriers who may be negative for LVH at the time of gene diagnosis and warrants periodic supervision of carriers throughout their lives.
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Affiliation(s)
- Don R McTaggart
- Cardiology, Launceston General Hospital, Launceston, Tas, Australia.
| | - Kathryn J Ogden
- School of Medicine, University of Tasmania, Hobart, TAS, Australia
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Jørgenrud B, Jalanko M, Heliö T, Jääskeläinen P, Laine M, Hilvo M, Nieminen MS, Laakso M, Hyötyläinen T, Orešič M, Kuusisto J. The Metabolome in Finnish Carriers of the MYBPC3-Q1061X Mutation for Hypertrophic Cardiomyopathy. PLoS One 2015; 10:e0134184. [PMID: 26267065 PMCID: PMC4534205 DOI: 10.1371/journal.pone.0134184] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 07/06/2015] [Indexed: 12/22/2022] Open
Abstract
Aims Mutations in the cardiac myosin-binding protein C gene (MYBPC3) are the most common genetic cause of hypertrophic cardiomyopathy (HCM) worldwide. The molecular mechanisms leading to HCM are poorly understood. We investigated the metabolic profiles of mutation carriers with the HCM-causing MYBPC3-Q1061X mutation with and without left ventricular hypertrophy (LVH) and non-affected relatives, and the association of the metabolome to the echocardiographic parameters. Methods and Results 34 hypertrophic subjects carrying the MYBPC3-Q1061X mutation, 19 non-hypertrophic mutation carriers and 20 relatives with neither mutation nor hypertrophy were examined using comprehensive echocardiography. Plasma was analyzed for molecular lipids and polar metabolites using two metabolomics platforms. Concentrations of branched chain amino acids, triglycerides and ether phospholipids were increased in mutation carriers with hypertrophy as compared to controls and non-hypertrophic mutation carriers, and correlated with echocardiographic LVH and signs of diastolic and systolic dysfunction in subjects with the MYBPC3-Q1061X mutation. Conclusions Our study implicates the potential role of branched chain amino acids, triglycerides and ether phospholipids in HCM, as well as suggests an association of these metabolites with remodeling and dysfunction of the left ventricle.
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Affiliation(s)
- Benedicte Jørgenrud
- Hormone laboratory, Aker hospital, Oslo University Hospital, Oslo, Norway
- Division of Women and Children’s Health, Department of Pediatric Research, Oslo University Hospital, Oslo, Norway
| | - Mikko Jalanko
- Helsinki University Central Hospital, Department of Cardiology, Helsinki, Finland
| | - Tiina Heliö
- Helsinki University Central Hospital, Department of Cardiology, Helsinki, Finland
| | | | - Mika Laine
- Helsinki University Central Hospital, Department of Cardiology, Helsinki, Finland
| | - Mika Hilvo
- VTT Technical Research Centre of Finland, Espoo, Finland
| | - Markku S. Nieminen
- Helsinki University Central Hospital, Department of Cardiology, Helsinki, Finland
| | - Markku Laakso
- University of Eastern Finland and Kuopio University Hospital, Department of Medicine, Kuopio, Finland
| | - Tuulia Hyötyläinen
- Steno Diabetes Center, 2820 Gentofte, Denmark
- VTT Technical Research Centre of Finland, Espoo, Finland
| | - Matej Orešič
- Steno Diabetes Center, 2820 Gentofte, Denmark
- VTT Technical Research Centre of Finland, Espoo, Finland
- * E-mail:
| | - Johanna Kuusisto
- University of Eastern Finland and Kuopio University Hospital, Department of Medicine, Kuopio, Finland
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Lee TM, Ware SM. Toward Personalized Medicine: Does Genetic Diagnosis of Pediatric Cardiomyopathy Influence Patient Management? PROGRESS IN PEDIATRIC CARDIOLOGY 2015; 39:43-47. [PMID: 26380543 DOI: 10.1016/j.ppedcard.2015.01.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A goal of personalized medicine is to provide increasingly sophisticated, individualized approaches to management and therapy for disease. Genetics is the engine that drives personalized medicine, holding the promise of therapeutics directed toward the unique needs of each patient. The 3rd International Conference on Cardiomyopathy in Children provided a forum to discuss the current status of personalized approaches to diagnosis, management, and therapy in the pediatric cardiomyopathy population. This review will focus on the importance of genetic diagnosis in this population as a necessary first step toward understanding the best approach to management and influencing disease outcome. The genetic heterogeneity of cardiomyopathy in children, the implications of specific genotypes, the ability to risk stratify based on genotype, and the impact on cascade screening in family members will be discussed.
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Affiliation(s)
- Teresa M Lee
- Department of Pediatrics, Division of Pediatric Cardiology, Columbia University Medical Center, New York, NY 10032
| | - Stephanie M Ware
- Department of Pediatrics and Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202
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Russell M, Roberts AE, Abrams DJ, Murphy AM, Towbin JA, Chung WK. How to effectively utilize genetic testing in the care of children with cardiomyopathies. PROGRESS IN PEDIATRIC CARDIOLOGY 2015. [DOI: 10.1016/j.ppedcard.2015.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Liu X, Jiang T, Piao C, Li X, Guo J, Zheng S, Zhang X, Cai T, Du J. Screening Mutations of MYBPC3 in 114 Unrelated Patients with Hypertrophic Cardiomyopathy by Targeted Capture and Next-generation Sequencing. Sci Rep 2015; 5:11411. [PMID: 26090888 PMCID: PMC4473690 DOI: 10.1038/srep11411] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 05/22/2015] [Indexed: 11/09/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a major cause of sudden cardiac death. Mutations in the MYBPC3 gene represent the cause of HCM in ~35% of patients with HCM. However, genetic testing in clinic setting has been limited due to the cost and relatively time-consuming by Sanger sequencing. Here, we developed a HCM Molecular Diagnostic Kit enabling ultra-low-cost targeted gene resequencing in a large cohort and investigated the mutation spectrum of MYBPC3. In a cohort of 114 patients with HCM, a total of 20 different mutations (8 novel and 12 known mutations) of MYBPC3 were identified from 25 patients (21.9%). We demonstrated that the power of targeted resequencing in a cohort of HCM patients, and found that MYBPC3 is a common HCM-causing gene in Chinese patients. Phenotype-genotype analyses showed that the patients with double mutations (n = 2) or premature termination codon mutations (n = 12) showed more severe manifestations, compared with patients with missense mutations (n = 11). Particularly, we identified a recurrent truncation mutation (p.Y842X) in four unrelated cases (4/25, 16%), who showed severe phenotypes, and suggest that the p.Y842X is a frequent mutation in Chinese HCM patients with severe phenotypes.
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Affiliation(s)
- Xuxia Liu
- 1] Beijing Anzhen Hospital, Capital Medical University, Beijing, China [2] Beijing Collaborative Innovation Center for Cardiovascular Disorders [3] The Key Laboratory of Remodeling-Related Cardiovascular Diseases, Capital Medical University, Ministry of Education, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing 100029, China
| | - Tengyong Jiang
- Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Chunmei Piao
- 1] Beijing Anzhen Hospital, Capital Medical University, Beijing, China [2] Beijing Collaborative Innovation Center for Cardiovascular Disorders [3] The Key Laboratory of Remodeling-Related Cardiovascular Diseases, Capital Medical University, Ministry of Education, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing 100029, China
| | - Xiaoyan Li
- 1] Beijing Anzhen Hospital, Capital Medical University, Beijing, China [2] Beijing Collaborative Innovation Center for Cardiovascular Disorders [3] The Key Laboratory of Remodeling-Related Cardiovascular Diseases, Capital Medical University, Ministry of Education, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing 100029, China
| | - Jun Guo
- 1] Beijing Anzhen Hospital, Capital Medical University, Beijing, China [2] Beijing Collaborative Innovation Center for Cardiovascular Disorders [3] The Key Laboratory of Remodeling-Related Cardiovascular Diseases, Capital Medical University, Ministry of Education, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing 100029, China
| | - Shuai Zheng
- 1] Beijing Anzhen Hospital, Capital Medical University, Beijing, China [2] Beijing Collaborative Innovation Center for Cardiovascular Disorders [3] The Key Laboratory of Remodeling-Related Cardiovascular Diseases, Capital Medical University, Ministry of Education, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing 100029, China
| | - Xiaoping Zhang
- 1] Beijing Anzhen Hospital, Capital Medical University, Beijing, China [2] Beijing Collaborative Innovation Center for Cardiovascular Disorders [3] The Key Laboratory of Remodeling-Related Cardiovascular Diseases, Capital Medical University, Ministry of Education, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing 100029, China
| | - Tao Cai
- Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Jie Du
- 1] Beijing Anzhen Hospital, Capital Medical University, Beijing, China [2] Beijing Collaborative Innovation Center for Cardiovascular Disorders [3] The Key Laboratory of Remodeling-Related Cardiovascular Diseases, Capital Medical University, Ministry of Education, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing 100029, China
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Hedberg Oldfors C, Máthé G, Thomson K, Tulinius M, Karason K, Östman-Smith I, Oldfors A. Early onset cardiomyopathy in females with Danon disease. Neuromuscul Disord 2015; 25:493-501. [PMID: 25900304 DOI: 10.1016/j.nmd.2015.03.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 03/04/2015] [Accepted: 03/11/2015] [Indexed: 11/18/2022]
Abstract
Danon disease is caused by mutations in the lysosome-associated membrane protein-2 gene, LAMP2, located on the X chromosome. Female carriers with LAMP2 mutations most often present with late onset cardiomyopathy and slow disease progress; however, there are unusual cases that emerge early and show a more severe disease course. We investigated the explanted heart and skeletal muscle biopsies in two girls, aged ten and thirteen years, who underwent cardiac transplantation because of hypertrophic cardiomyopathy secondary to LAMP2 mutations and a 41-year old female with late-onset familial LAMP2 cardiomyopathy with more typical clinical phenotype. The two girls in contrast had clinical features that mimicked severe primary hypertrophic cardiomyopathy caused by mutations in genes encoding sarcomeric proteins. Immunohistochemistry in cardiac muscles showed a remarkable pattern with lack of LAMP2 protein in large regions including thousands of cardiomyocytes that also showed myocyte hypertrophy, lysosomal enlargement and disarray. In other equally large regions there were preserved LAMP2 expression and nearly normal histology. The skeletal muscle biopsy revealed no pathological changes. An uneven distribution of LAMP2 protein may cause deleterious effects depending on which regions of the myocardium are lacking LAMP2 protein in spite of an overall moderate reduction of LAMP2 protein. This may be a more common mechanism behind early aggressive disease in females than an overall skewed X-chromosome inactivation in the tissue.
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Affiliation(s)
| | - Gyöngyvér Máthé
- Department of Clinical Pathology and Genetics, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Kate Thomson
- Regional Molecular Genetics Laboratory, Churchill Hospital, Oxford, UK
| | - Mar Tulinius
- Department of Paediatrics, The Queen Silvia Children's Hospital, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Kristjan Karason
- Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Ingegerd Östman-Smith
- Department of Paediatric Cardiology, The Queen Silvia Children's Hospital, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Anders Oldfors
- Department of Pathology, University of Gothenburg, Gothenburg, Sweden
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Ho CY, Charron P, Richard P, Girolami F, Van Spaendonck-Zwarts KY, Pinto Y. Genetic advances in sarcomeric cardiomyopathies: state of the art. Cardiovasc Res 2015; 105:397-408. [PMID: 25634555 PMCID: PMC4349164 DOI: 10.1093/cvr/cvv025] [Citation(s) in RCA: 155] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Genetic studies in the 1980s and 1990s led to landmark discoveries that sarcomere mutations cause both hypertrophic and dilated cardiomyopathies. Sarcomere mutations also likely play a role in more complex phenotypes and overlap cardiomyopathies with features of hypertrophy, dilation, diastolic abnormalities, and non-compaction. Identification of the genetic cause of these important conditions provides unique opportunities to interrogate and characterize disease pathogenesis and pathophysiology, starting from the molecular level and expanding from there. With such insights, there is potential for clinical translation that may transform management of patients and families with inherited cardiomyopathies. If key pathways for disease development can be identified, they could potentially serve as targets for novel disease-modifying or disease-preventing therapies. By utilizing gene-based diagnostic testing, we can identify at-risk individuals prior to the onset of clinical disease, allowing for disease-modifying therapy to be initiated early in life, at a time that such treatment may be most successful. In this section, we review the current application of genetics in clinical management, focusing on hypertrophic cardiomyopathy as a paradigm; discuss state-of-the-art genetic testing technology; review emerging knowledge of gene expression in sarcomeric cardiomyopathies; and discuss both the prospects, as well as the challenges, of bringing genetics to medicine.
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Affiliation(s)
- Carolyn Y Ho
- Cardiovascular Division, Brigham and Women's Hospital, Boston, MA, USA
| | - Philippe Charron
- Centre de référence maladies cardiaques héréditaires, ICAN, Inserm UMR_1166, Hôpital Pitié-Salpêtrière, AP-HP, Paris, France Université de Versailles-Saint Quentin, Hôpital Ambroise Paré, AP-HP, Boulogne-Billancourt, France
| | - Pascale Richard
- Centre de référence maladies cardiaques héréditaires, ICAN, Inserm UMR_1166, Hôpital Pitié-Salpêtrière, AP-HP, Paris, France
| | | | - Karin Y Van Spaendonck-Zwarts
- Department of Clinical Genetics, Academic Medical Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Yigal Pinto
- Department of Cardiology, Academic Medical Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
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Marsiglia JDC, Pereira AC. Hypertrophic cardiomyopathy: how do mutations lead to disease? Arq Bras Cardiol 2014; 102:295-304. [PMID: 24714796 PMCID: PMC3987320 DOI: 10.5935/abc.20140022] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 08/23/2013] [Indexed: 12/13/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is the most common monogenic genetic cardiac
disease, with an estimated prevalence of 1:500 in the general population. Clinically,
HCM is characterized by hypertrophy of the left ventricle (LV) walls, especially the
septum, usually asymmetric, in the absence of any cardiac or systemic disease that
leads to a secondary hypertrophy. The clinical course of the disease has a large
inter- and intrafamilial heterogeneity, ranging from mild symptoms of heart failure
late in life to the onset of sudden cardiac death at a young age and is caused by a
mutation in one of the genes that encode a protein from the sarcomere, Z-disc or
intracellular calcium modulators. Although many genes and mutations are already known
to cause HCM, the molecular pathways that lead to the phenotype are still unclear.
This review focus on the molecular mechanisms of HCM, the pathways from mutation to
clinical phenotype and how the disease's genotype correlates with phenotype.
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Affiliation(s)
- Júlia Daher Carneiro Marsiglia
- Mailing Address: Júlia Daher Carneiro Marsiglia, Av. Dr. Enéas de
Carvalho Aguiar, 44, Cerqueira César. Postal Code 05403- 900, São Paulo, SP - Brazil.
E-mail: ;
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Friedrich FW, Reischmann S, Schwalm A, Unger A, Ramanujam D, Münch J, Müller OJ, Hengstenberg C, Galve E, Charron P, Linke WA, Engelhardt S, Patten M, Richard P, van der Velden J, Eschenhagen T, Isnard R, Carrier L. FHL2 expression and variants in hypertrophic cardiomyopathy. Basic Res Cardiol 2014; 109:451. [PMID: 25358972 PMCID: PMC4215105 DOI: 10.1007/s00395-014-0451-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 10/04/2014] [Accepted: 10/22/2014] [Indexed: 11/28/2022]
Abstract
Based on evidence that FHL2 (four and a half LIM domains protein 2) negatively regulates cardiac hypertrophy we tested whether FHL2 altered expression or variants could be associated with hypertrophic cardiomyopathy (HCM). HCM is a myocardial disease characterized by left ventricular hypertrophy, diastolic dysfunction and increased interstitial fibrosis and is mainly caused by mutations in genes coding for sarcomeric proteins. FHL2 mRNA level, FHL2 protein level and I-band-binding density were lower in HCM patients than control individuals. Screening of 121 HCM patients without mutations in established disease genes identified 2 novel (T171M, V187L) and 4 known (R177Q, N226N, D268D, P273P) FHL2 variants in unrelated HCM families. We assessed the structural and functional consequences of the nonsynonymous substitutions after adeno-associated viral-mediated gene transfer in cardiac myocytes and in 3D-engineered heart tissue (EHT). Overexpression of FHL2 wild type or nonsynonymous substitutions in cardiac myocytes markedly down-regulated α-skeletal actin and partially blunted hypertrophy induced by phenylephrine or endothelin-1. After gene transfer in EHTs, force and velocity of both contraction and relaxation were higher with T171M and V187L FHL2 variants than wild type under basal conditions. Finally, chronic phenylephrine stimulation depressed EHT function in all groups, but to a lower extent in T171M-transduced EHTs. These data suggest that (1) FHL2 is down-regulated in HCM, (2) both FHL2 wild type and variants partially protected phenylephrine- or endothelin-1-induced hypertrophy in cardiac myocytes, and (3) FHL2 T171M and V187L nonsynonymous variants induced altered EHT contractility. These findings provide evidence that the 2 novel FHL2 variants could increase cardiac function in HCM.
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Affiliation(s)
- Felix W. Friedrich
- Department of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Silke Reischmann
- Department of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Aileen Schwalm
- Department of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Andreas Unger
- Department of Cardiovascular Physiology, Ruhr University Bochum, Bochum, Germany
| | - Deepak Ramanujam
- Institute of Pharmacology and Toxicology, Technical University Munich, Munich, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Munich, Munich, Germany
| | - Julia Münch
- University Heart Center Hamburg, Hamburg, Germany
| | - Oliver J. Müller
- Department of Cardiology, Internal Medicine III, University Hospital Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
| | - Christian Hengstenberg
- Present Address: German Heart Centre of the Technical University Munich, Munich, Germany
- Klinik und Poliklinik für Innere Medizin II, Universitätsklinikum Regensburg, Regensburg, Germany
| | - Enrique Galve
- Unitat d’Insuficiència Cardiaca, Servei de Cardiologia, Hospital Vall d’Hebron, Barcelona, Spain
| | - Philippe Charron
- Inserm, U956, Paris, France
- ICAN Institute, UPMC Univ Paris 06, Paris, France
| | - Wolfgang A. Linke
- Department of Cardiovascular Physiology, Ruhr University Bochum, Bochum, Germany
| | - Stefan Engelhardt
- Institute of Pharmacology and Toxicology, Technical University Munich, Munich, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Munich, Munich, Germany
| | | | - Pascale Richard
- Inserm, U956, Paris, France
- ICAN Institute, UPMC Univ Paris 06, Paris, France
- Groupe Hospitalier Pitié-Salpêtrière, AP-HP Centre de référence des maladies cardiaques héréditaires, Paris, France
- Groupe Hospitalier Pitié-Salpêtrière, AP-HP,UF Cardiogénétique et Myogénétique, Paris, France
| | - Jolanda van der Velden
- Laboratory for Physiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands
| | - Thomas Eschenhagen
- Department of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Richard Isnard
- Inserm, U956, Paris, France
- ICAN Institute, UPMC Univ Paris 06, Paris, France
- Groupe Hospitalier Pitié-Salpêtrière, AP-HP Centre de référence des maladies cardiaques héréditaires, Paris, France
| | - Lucie Carrier
- Department of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
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Lopes LR, Syrris P, Guttmann OP, O'Mahony C, Tang HC, Dalageorgou C, Jenkins S, Hubank M, Monserrat L, McKenna WJ, Plagnol V, Elliott PM. Novel genotype-phenotype associations demonstrated by high-throughput sequencing in patients with hypertrophic cardiomyopathy. Heart 2014; 101:294-301. [PMID: 25351510 PMCID: PMC4345808 DOI: 10.1136/heartjnl-2014-306387] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Objective A predictable relation between genotype and disease expression is needed in order to use genetic testing for clinical decision-making in hypertrophic cardiomyopathy (HCM). The primary aims of this study were to examine the phenotypes associated with sarcomere protein (SP) gene mutations and test the hypothesis that variation in non-sarcomere genes modifies the phenotype. Methods Unrelated and consecutive patients were clinically evaluated and prospectively followed in a specialist clinic. High-throughput sequencing was used to analyse 41 genes implicated in inherited cardiac conditions. Variants in SP and non-SP genes were tested for associations with phenotype and survival. Results 874 patients (49.6±15.4 years, 67.8% men) were studied; likely disease-causing SP gene variants were detected in 383 (43.8%). Patients with SP variants were characterised by younger age and higher prevalence of family history of HCM, family history of sudden cardiac death, asymmetric septal hypertrophy, greater maximum LV wall thickness (all p values<0.0005) and an increased incidence of cardiovascular death (p=0.012). Similar associations were observed for individual SP genes. Patients with ANK2 variants had greater maximum wall thickness (p=0.0005). Associations at a lower level of significance were demonstrated with variation in other non-SP genes. Conclusions Patients with HCM caused by rare SP variants differ with respect to age at presentation, family history of the disease, morphology and survival from patients without SP variants. Novel associations for SP genes are reported and, for the first time, we demonstrate possible influence of variation in non-SP genes associated with other forms of cardiomyopathy and arrhythmia syndromes on the clinical phenotype of HCM.
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Affiliation(s)
- Luis R Lopes
- UCL Institute of Cardiovascular Science, London, UK
| | | | | | - Constantinos O'Mahony
- UCL Institute of Cardiovascular Science, London, UK The London Chest Hospital, London, UK
| | - Hak Chiaw Tang
- UCL Institute of Cardiovascular Science, London, UK National Heart Centre, Singapore, Singapore
| | | | | | - Mike Hubank
- UCL Genomics, Department of Molecular Haematology and Cancer Biology, UCL Institute of Child Health, London, UK
| | - Lorenzo Monserrat
- Instituto de Investigación Biomédica de la Universidad de A Coruña (INIBIC), Complexo Hospitalario Universitario de A Coruña (CHUAC)-Universidad de A Coruña, A Coruña, Spain
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Witjas-Paalberends ER, Güçlü A, Germans T, Knaapen P, Harms HJ, Vermeer AMC, Christiaans I, Wilde AAM, Dos Remedios C, Lammertsma AA, van Rossum AC, Stienen GJM, van Slegtenhorst M, Schinkel AF, Michels M, Ho CY, Poggesi C, van der Velden J. Gene-specific increase in the energetic cost of contraction in hypertrophic cardiomyopathy caused by thick filament mutations. Cardiovasc Res 2014; 103:248-57. [PMID: 24835277 DOI: 10.1093/cvr/cvu127] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIMS Disease mechanisms regarding hypertrophic cardiomyopathy (HCM) are largely unknown and disease onset varies. Sarcomere mutations might induce energy depletion for which until now there is no direct evidence at sarcomere level in human HCM. This study investigated if mutations in genes encoding myosin-binding protein C (MYBPC3) and myosin heavy chain (MYH7) underlie changes in the energetic cost of contraction in the development of human HCM disease. METHODS AND RESULTS Energetic cost of contraction was studied in vitro by measurements of force development and ATPase activity in cardiac muscle strips from 26 manifest HCM patients (11 MYBPC3mut, 9 MYH7mut, and 6 sarcomere mutation-negative, HCMsmn). In addition, in vivo, the ratio between external work (EW) and myocardial oxygen consumption (MVO2) to obtain myocardial external efficiency (MEE) was determined in 28 pre-hypertrophic mutation carriers (14 MYBPC3mut and 14 MYH7mut) and 14 healthy controls using [(11)C]-acetate positron emission tomography and cardiovascular magnetic resonance imaging. Tension cost (TC), i.e. ATPase activity during force development, was higher in MYBPC3mut and MYH7mut compared with HCMsmn at saturating [Ca(2+)]. TC was also significantly higher in MYH7mut at submaximal, more physiological [Ca(2+)]. EW was significantly lower in both mutation carrier groups, while MVO2 did not differ. MEE was significantly lower in both mutation carrier groups compared with controls, showing the lowest efficiency in MYH7 mutation carriers. CONCLUSION We provide direct evidence that sarcomere mutations perturb the energetic cost of cardiac contraction. Gene-specific severity of cardiac abnormalities may underlie differences in disease onset and suggests that early initiation of metabolic treatment may be beneficial, in particular, in MYH7 mutation carriers.
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Affiliation(s)
- E Rosalie Witjas-Paalberends
- Department of Physiology, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Center, Amsterdam, The Netherlands
| | - Ahmet Güçlü
- Department of Cardiology, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands ICIN Netherlands Heart Institute, Utrecht, The Netherlands
| | - Tjeerd Germans
- Department of Cardiology, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Paul Knaapen
- Department of Cardiology, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Hendrik J Harms
- Department of Radiology and Nuclear Medicine, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Center, Amsterdam, The Netherlands
| | - Alexa M C Vermeer
- Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands
| | - Imke Christiaans
- Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands
| | - Arthur A M Wilde
- Department of Cardiology, Academic Medical Center, Amsterdam, The Netherlands
| | - Cris Dos Remedios
- Institute for Biomedical Research, Muscle Research Unit, University of Sydney, Sydney, Australia
| | - Adriaan A Lammertsma
- Department of Radiology and Nuclear Medicine, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Center, Amsterdam, The Netherlands
| | - Albert C van Rossum
- Department of Cardiology, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Ger J M Stienen
- Department of Physiology, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Center, Amsterdam, The Netherlands Department of Physics and Astronomy, VU University, Amsterdam, The Netherlands
| | | | - Arend F Schinkel
- Thorax Center, Cardiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Michelle Michels
- Thorax Center, Cardiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Carolyn Y Ho
- Brigham and Women's Hospital, Cardiology, Boston, MA, USA
| | - Corrado Poggesi
- Department of Physiology, University of Florence, Florence, Italy
| | - Jolanda van der Velden
- Department of Physiology, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Center, Amsterdam, The Netherlands ICIN Netherlands Heart Institute, Utrecht, The Netherlands
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Cardiac Anderson-Fabry disease: lessons from a 25-year-follow up. Rev Port Cardiol 2014; 33:247.e1-7. [PMID: 24830310 DOI: 10.1016/j.repc.2013.10.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 10/14/2013] [Accepted: 10/29/2013] [Indexed: 11/21/2022] Open
Abstract
Sarcomeric hypertrophic cardiomyopathy (HCM) is the most common genetic cause of unexplained left ventricular hypertrophy and has no specific treatment. Anderson-Fabry disease (AFD) is rare and usually multisystemic, but occasionally expresses clinically as a predominantly cardiac phenotype mimicking HCM. We describe an illustrative case of a patient followed regularly for 25 years with a diagnosis of familial HCM and no identified sarcomeric mutations. Next-generation sequencing analysis identified a novel pathogenic mutation in the GLA gene, leading to a diagnosis of previously unknown multisystemic AFD, with consequent implications for the patient's treatment and prognosis and familial screening.
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Cardiac Anderson‐Fabry disease: Lessons from a 25‐year‐follow up. REVISTA PORTUGUESA DE CARDIOLOGIA (ENGLISH EDITION) 2014. [DOI: 10.1016/j.repce.2013.10.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Barefield D, Kumar M, de Tombe PP, Sadayappan S. Contractile dysfunction in a mouse model expressing a heterozygous MYBPC3 mutation associated with hypertrophic cardiomyopathy. Am J Physiol Heart Circ Physiol 2014; 306:H807-15. [PMID: 24464755 PMCID: PMC3949045 DOI: 10.1152/ajpheart.00913.2013] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Accepted: 01/19/2014] [Indexed: 12/29/2022]
Abstract
The etiology of hypertrophic cardiomyopathy (HCM) has been ascribed to mutations in genes encoding sarcomere proteins. In particular, mutations in MYBPC3, a gene which encodes cardiac myosin binding protein-C (cMyBP-C), have been implicated in over one third of HCM cases. Of these mutations, 70% are predicted to result in C'-truncated protein products, which are undetectable in tissue samples. Heterozygous carriers of these truncation mutations exhibit varying penetrance of HCM, with symptoms often occurring later in life. We hypothesize that heterozygous carriers of MYBPC3 mutations, while seemingly asymptomatic, have subtle functional impairments that precede the development of overt HCM. This study compared heterozygous (+/t) knock-in MYBPC3 truncation mutation mice with wild-type (+/+) littermates to determine whether functional alterations occur at the whole-heart or single-cell level before the onset of hypertrophy. The +/t mice show ∼40% reduction in MYBPC3 transcription, but no changes in cMyBP-C level, phosphorylation status, or cardiac morphology. Nonetheless, +/t mice show significantly decreased maximal force development at sarcomere lengths of 1.9 μm (+/t 68.5 ± 4.1 mN/mm(2) vs. +/+ 82.2 ± 3.2) and 2.3 μm (+/t 79.2 ± 3.1 mN/mm(2) vs. +/+ 95.5 ± 2.4). In addition, heterozygous mice show significant reductions in vivo in the early/after (E/A) (+/t 1.74 ± 0.12 vs. +/+ 2.58 ± 0.43) and E'/A' (+/t 1.18 ± 0.05 vs. +/+ 1.52 ± 0.15) ratios, indicating diastolic dysfunction. These results suggest that seemingly asymptomatic heterozygous MYBPC3 carriers do suffer impairments that may presage the onset of HCM.
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Affiliation(s)
- David Barefield
- Department of Cell and Molecular Physiology, Health Sciences Division, Loyola University Chicago, Maywood, Illinois
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Charron P, Komajda M. Molecular genetics in hypertrophic cardiomyopathy: towards individualized management of the disease. Expert Rev Mol Diagn 2014; 6:65-78. [PMID: 16359268 DOI: 10.1586/14737159.6.1.65] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Hypertrophic cardiomyopathy is a relatively common genetic disease, affecting one person per 500 in the general population, and is clinically defined by the presence of unexplained left ventricular hypertrophy. Although recognized as the most common cause of sudden death in the young (especially in athletes), the cardiac expression of the disease is highly variable with respect to age at onset, degree of symptoms and risk of cardiac death. As a consequence, therapeutic strategies are diverse and must be adapted to the specific features of an individual. Recently, the molecular bases of the disease have been unraveled with the identification of a large number of mutations in genes encoding sarcomeric proteins. This review focuses on the impact of the molecular data on the understanding of the disease, and considers the emerging issues regarding the impact of molecular testing on the management of patients (or relatives) in clinical practice.
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Affiliation(s)
- Philippe Charron
- Centre of Reference for Cardiac Hereditary Diseases, Département de Génétique, Hôpital Pitié-Salpêtrière, 47 Boulevard de l'Hôpital, 75013 Paris, France.
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Abstract
The heritable cardiomyopathies are relatively common conditions that can lead to heart failure and sudden cardiac death. Family history collection, genetic testing and genetic counseling are recommended for these patients and families in multiple practice guidelines and consensus statements. Research discoveries and rapidly dropping costs of DNA sequencing technologies have resulted in the availability of multiple cardiomyopathy genetic testing panels. Genetic testing not only helps in determining the underlying etiology of idiopathic and familial cardiomyopathies, but is also a powerful tool in the determination of which relatives are at-risk and which are not. Both pre- and post-test genetic counseling is an imperative component of genetic testing, as there are many benefits and limitations of genetic testing that need discussed with each patient undergoing this process.
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Affiliation(s)
- Amy Curry Sturm
- Division of Human Genetics, Internal Medicine, Wexner Medical Center at The Ohio State University, 2001 Polaris Parkway, Columbus, OH 43240, USA.
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Lopes LR, Rahman MS, Elliott PM. A systematic review and meta-analysis of genotype-phenotype associations in patients with hypertrophic cardiomyopathy caused by sarcomeric protein mutations. Heart 2013; 99:1800-11. [PMID: 23674365 DOI: 10.1136/heartjnl-2013-303939] [Citation(s) in RCA: 140] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND The genetic basis of familial hypertrophic cardiomyopathy (HCM) is well described, but the relation between genotype and clinical phenotype is still poorly characterised. OBJECTIVE To summarise and critically review the current literature on genotype-phenotype associations in patients with HCM and to perform a meta-analysis on selected clinical features. DATA SOURCES PubMed/Medline was searched up to January 2013. Retrieved articles were checked for additional publications. SELECTION CRITERIA Observational, cross-sectional and prospectively designed English language human studies that analysed the relationship between the presence of mutations in sarcomeric protein genes and clinical parameters. DATA EXTRACTION AND ANALYSIS The pooled analysis was confined to studies reporting on cohorts of unrelated and consecutive patients in which at least two sarcomere genes were sequenced. A random effect meta-regression model was used to determine the overall prevalence of predefined clinical features: age at presentation, gender, family history of HCM, family history of sudden cardiac death (SCD), and maximum left ventricular wall thickness (MLVWT). The I(2) statistic was used to estimate the proportion of total variability in the prevalence data attributable to the heterogeneity between studies. RESULTS Eighteen publications (corresponding to a total of 2459 patients) were selected for the pooled analysis. The presence of any sarcomere gene mutation was associated with a younger age at presentation (38.4 vs 46.0 years, p<0.0005), a family history of HCM (50.6% vs 23.1%, p<0.0005), a family history of SCD (27.0% vs 14.9%, p<0.0005) and greater MLVWT (21.0 vs 19.3 mm, p=0.03). There were no differences when the two most frequently affected genes, MYBPC3 and MYH7, were compared. A total of 53 family studies were also included in the review. These were characterised by pronounced variability and the majority of studies reporting on outcomes analysed small cross-sectional cohorts and were unsuitable for pooled analyses. CONCLUSIONS The presence of a mutation in any sarcomere gene is associated with a number of clinical features. The heterogeneous nature of the disease and the inconsistency of study design precludes the establishment of more precise genotype-phenotype relationships. Large scale studies examining the relation between genotype, disease severity, and prognosis are required.
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Affiliation(s)
- Luís R Lopes
- Institute of Cardiovascular Science, University College London, , London, UK
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40
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Witjas-Paalberends ER, Piroddi N, Stam K, van Dijk SJ, Oliviera VS, Ferrara C, Scellini B, Hazebroek M, ten Cate FJ, van Slegtenhorst M, dos Remedios C, Niessen HWM, Tesi C, Stienen GJM, Heymans S, Michels M, Poggesi C, van der Velden J. Mutations in MYH7 reduce the force generating capacity of sarcomeres in human familial hypertrophic cardiomyopathy. Cardiovasc Res 2013; 99:432-41. [PMID: 23674513 DOI: 10.1093/cvr/cvt119] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS Familial hypertrophic cardiomyopathy (HCM), frequently caused by sarcomeric gene mutations, is characterized by cellular dysfunction and asymmetric left-ventricular (LV) hypertrophy. We studied whether cellular dysfunction is due to an intrinsic sarcomere defect or cardiomyocyte remodelling. METHODS AND RESULTS Cardiac samples from 43 sarcomere mutation-positive patients (HCMmut: mutations in thick (MYBPC3, MYH7) and thin (TPM1, TNNI3, TNNT2) myofilament genes) were compared with 14 sarcomere mutation-negative patients (HCMsmn), eight patients with secondary LV hypertrophy due to aortic stenosis (LVHao) and 13 donors. Force measurements in single membrane-permeabilized cardiomyocytes revealed significantly lower maximal force generating capacity (Fmax) in HCMmut (21 ± 1 kN/m²) and HCMsmn (26 ± 3 kN/m²) compared with donor (36 ± 2 kN/m²). Cardiomyocyte remodelling was more severe in HCMmut compared with HCMsmn based on significantly lower myofibril density (49 ± 2 vs. 63 ± 5%) and significantly higher cardiomyocyte area (915 ± 15 vs. 612 ± 11 μm²). Low Fmax in MYBPC3mut, TNNI3mut, HCMsmn, and LVHao was normalized to donor values after correction for myofibril density. However, Fmax was significantly lower in MYH7mut, TPM1mut, and TNNT2mut even after correction for myofibril density. In accordance, measurements in single myofibrils showed very low Fmax in MYH7mut, TPM1mut, and TNNT2mut compared with donor (respectively, 73 ± 3, 70 ± 7, 83 ± 6, and 113 ± 5 kN/m²). In addition, force was lower in MYH7mut cardiomyocytes compared with MYBPC3mut, HCMsmn, and donor at submaximal [Ca²⁺]. CONCLUSION Low cardiomyocyte Fmax in HCM patients is largely explained by hypertrophy and reduced myofibril density. MYH7 mutations reduce force generating capacity of sarcomeres at maximal and submaximal [Ca²⁺]. These hypocontractile sarcomeres may represent the primary abnormality in patients with MYH7 mutations.
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Affiliation(s)
- E Rosalie Witjas-Paalberends
- Laboratory for Physiology, VU University Medical Center, Institute for Cardiovascular Research, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands.
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Shiozaki AA, Senra T, Arteaga E, Martinelli Filho M, Pita CG, Ávila LFR, Parga Filho JR, Mady C, Kalil-Filho R, Bluemke DA, Rochitte CE. Myocardial fibrosis detected by cardiac CT predicts ventricular fibrillation/ventricular tachycardia events in patients with hypertrophic cardiomyopathy. J Cardiovasc Comput Tomogr 2013; 7:173-81. [PMID: 23849490 DOI: 10.1016/j.jcct.2013.04.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 04/21/2013] [Accepted: 04/23/2013] [Indexed: 12/12/2022]
Abstract
BACKGROUND Myocardial fibrosis (MF) occurs in up to 80% of subjects with asymptomatic or mildly symptomatic hypertrophic cardiomyopathy (HCM) and can constitute an arrhythmogenic substrate for re-entrant, life-threatening ventricular arrhythmias in predisposed persons. OBJECTIVE The aim was to investigate whether MF detected by delayed enhancement cardiac CT is predictive of ventricular tachycardia (VT) and fibrillation (VF) that require appropriate therapy by an implantable cardioverter defibrillator (ICD) in patients with HCM. METHODS Twenty-six patients with HCM with previously (for at least 1 year) implanted ICD underwent MF evaluation by cardiac CT. MF was quantified by myocardial delayed enhanced cardiac CT. Data on ICD firing were recorded every 3 months after ICD implantation. Risk factors for sudden cardiac death in patients with HCM were evaluated in all patients. RESULTS MF was present in 25 of 26 patients (96%) with mean fibrosis mass of 20.5 ± 15.8 g. Patients with appropriate ICD shocks for VF/VT had significantly greater MF mass than patients without (29.10 ± 19.13 g vs 13.57 ± 8.31 g; P = .01). For a MF mass of at least 18 g, sensitivity and specificity for appropriate ICD firing were 73% (95% CI, 49%-88%) and 71% (95% CI, 56%-81%), respectively. Kaplan-Meier curves indicated a significantly greater VF/VT event rate in patients with MF mass ≥18 g than in patients with MF <18 g (P = .02). In the Cox regression analysis, the amount of MF was independently associated with VF/VT in ICD-stored electrograms. CONCLUSION The mass of MF detected by cardiac CT in patients with HCM at high risk of sudden death was associated with appropriate ICD firings.
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Affiliation(s)
- Afonso Akio Shiozaki
- Cardiovascular Magnetic Resonance and Computed Tomography Sector, Heart Institute, InCor, University of São Paulo Medical School, São Paulo, Brazil
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Lopes LR, Zekavati A, Syrris P, Hubank M, Giambartolomei C, Dalageorgou C, Jenkins S, McKenna W, Plagnol V, Elliott PM. Genetic complexity in hypertrophic cardiomyopathy revealed by high-throughput sequencing. J Med Genet 2013; 50:228-39. [PMID: 23396983 PMCID: PMC3607113 DOI: 10.1136/jmedgenet-2012-101270] [Citation(s) in RCA: 157] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Background Clinical interpretation of the large number of rare variants identified by high throughput sequencing (HTS) technologies is challenging. The aim of this study was to explore the clinical implications of a HTS strategy for patients with hypertrophic cardiomyopathy (HCM) using a targeted HTS methodology and workflow developed for patients with a range of inherited cardiovascular diseases. By comparing the sequencing results with published findings and with sequence data from a large-scale exome sequencing screen of UK individuals, we sought to quantify the strength of the evidence supporting causality for detected candidate variants. Methods and results 223 unrelated patients with HCM (46±15 years at diagnosis, 74% males) were studied. In order to analyse coding, intronic and regulatory regions of 41 cardiovascular genes, we used solution-based sequence capture followed by massive parallel resequencing on Illumina GAIIx. Average read-depth in the 2.1 Mb target region was 120. Rare (frequency<0.5%) non-synonymous, loss-of-function and splice-site variants were defined as candidates. Excluding titin, we identified 152 distinct candidate variants in sarcomeric or associated genes (89 novel) in 143 patients (64%). Four sarcomeric genes (MYH7, MYBPC3, TNNI3, TNNT2) showed an excess of rare single non-synonymous single-nucleotide polymorphisms (nsSNPs) in cases compared to controls. The estimated probability that a nsSNP in these genes is pathogenic varied between 57% and near certainty depending on the location. We detected an additional 94 candidate variants (73 novel) in desmosomal, and ion-channel genes in 96 patients (43%). Conclusions This study provides the first large-scale quantitative analysis of the prevalence of sarcomere protein gene variants in patients with HCM using HTS technology. Inclusion of other genes implicated in inherited cardiac disease identifies a large number of non-synonymous rare variants of unknown clinical significance.
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Affiliation(s)
- Luis R Lopes
- The Heart Hospital, 16-18 Westmoreland Street, London W1G 8PH, UK.
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Di Domenico M, Casadonte R, Ricci P, Santini M, Frati G, Rizzo A, Carratelli CR, Lamberti M, Parrotta E, Quaresima B, Faniello CM, Costanzo F, Cuda G. Cardiac and skeletal muscle expression of mutant β-myosin heavy chains, degree of functional impairment and phenotypic heterogeneity in hypertrophic cardiomyopathy. J Cell Physiol 2012; 227:3471-6. [PMID: 22213221 DOI: 10.1002/jcp.24047] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Several mutations in distinct genes, all coding for sarcomeric proteins, have been reported in unrelated kindreds with familial hypertrophic cardiomyopathy (FHC). We have identified nine individuals from three families harboring two distinct mutations in one copy of the β-myosin heavy chain (β-MHC) gene. In this study, the expression of the mutant β-myosin protein isoform, isolated from slow-twitch fibers of skeletal muscle, was demonstrated by Northern and Western blot analysis; this myosin showed a decreased in vitro motility activity and produced a lower actin-activated ATPase activity. Isometric tension, measured in single slow-twitch fibers isolated from the affected individuals, also showed a significant decrease. The degree of impairment of β-myosin function, as well as the loss in isometric tension development, were strictly dependent on the amount of the isoform transcribed from the mutated allele. Interestingly, a strong correlation was also demonstrated between mutant β-myosin content and clinical features of FHC. On the other hand, we were unable to detect any correlation between mutant β-myosin expression and degree of cardiac hypertrophy, thereby strengthening the hypothesis that hypertrophy, one of the hallmarks of FHC, might not necessarily be related to the clinical evolution of this disease. These findings lend support to the notion that additional factors rather than the mutated gene may play a pathogenetic role in cardiac wall thickening, whereas the prognosis appears to be strongly related to the amount of mutant protein.
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Marian A. Recent advances in genetics and treatment of hypertrophic cardiomyopathy. Future Cardiol 2012; 1:341-53. [PMID: 19804117 DOI: 10.1517/14796678.1.3.341] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is an intriguing disease with various clinical manifestations, ranging from sudden cardiac death to heart failure. The molecular genetics of HCM are all but elucidated and over 200 mutations in more than a dozen genes have been identified. Conventional therapeutic agents, namely beta-blockers and calcium channel blockers, could provide symptomatic relief but are not known to reduce mortality or induce regression of phenotype. Studies in genetic animal models suggest cardiac hypertrophy and fibrosis, a major histological feature of HCM, may be reversed or prevented through blockade of molecules involved in the pathogenesis of HCM. Surgical myomectomy and ethanol-induced septal ablation are effective procedures for reducing the left ventricular outflow tract obstruction and hence, symptomatic improvement. Randomized studies are needed to compare the effectiveness of medical therapy, ethanol septal ablation and surgical myomectomy in treatment of patients with HCM.
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Affiliation(s)
- Aj Marian
- Baylor College of Medicine, One Baylor Plaza, 519D Houston, TX 77030, USA.
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Tamarappoo BK, John BT, Reinier K, Teodorescu C, Uy-Evanado A, Gunson K, Jui J, Chugh SS. Vulnerable myocardial interstitium in patients with isolated left ventricular hypertrophy and sudden cardiac death: a postmortem histological evaluation. J Am Heart Assoc 2012; 1:e001511. [PMID: 23130141 PMCID: PMC3487319 DOI: 10.1161/jaha.112.001511] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Accepted: 04/24/2012] [Indexed: 12/11/2022]
Abstract
BACKGROUND Concentric left ventricular hypertrophy (LVH) is independently associated with increased risk of sudden cardiac death (SCD). Some animal models of LVH display specific alterations of the myocardial interstitium that could increase myocardial vulnerability to ventricular arrhythmias, but these merit evaluation in humans with LVH and SCD. METHODS AND RESULTS Twelve consecutive patients with isolated LVH and SCD (LVH+SCD) in the absence of hypertrophic cardiomyopathy, coronary disease, or other cardiac structural abnormality were ascertained in the Oregon Sudden Unexpected Death Study. Detailed postmortem comparisons were conducted with 18 controls who had isolated LVH and unnatural deaths (Control Group A) and 6 controls who had structurally normal hearts and unnatural deaths (Control Group B). Postmortem left ventricular myocardial sections were obtained for measurement of collagen volume fraction, characterization of gap junctions, and quantification of collagen subtypes. Heart weight normalized to body weight was higher in LVH+SCD cases (6.9±1.2 g/kg) than in Control Group A (5.3±1.4 g/kg) and Control Group B (4.2±0.3 g/kg); P=0.001. Collagen volume fraction was also higher in LVH+SCD cases (3.1±0.4) than in Control Group A (2.3±0.4) and Control Group B (1.6±0.3); P=0.0002. The relative amount of collagen III was significantly higher in LVH+SCD cases (33.0±4.4%) than in Control Group A (20.9±4.3%) and Control Group B (13.4±3.5%); P=0.0001. There was an overall increase in the number of connexin 43-labeled gap junctions with increasing myocyte size. No subject was found to have high-risk hypertrophic cardiomyopathy mutations. CONCLUSIONS In addition to the expected increase in myocardial mass and overall collagen content, SCD with isolated LVH was associated with relative abundance of type III collagen, a novel finding that warrants further mechanistic evaluation. (J Am Heart Assoc. 2012;1:e001511 doi: 10.1161/JAHA.111.001511.).
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Affiliation(s)
- Balaji K. Tamarappoo
- Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (B.K.T., B.T.J., K.R., C.T.,
A.U.-E., S.S.C.)
- Cleveland Clinic Foundation, Cleveland OH (B.K.T.)
| | - Benjamin T. John
- Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (B.K.T., B.T.J., K.R., C.T.,
A.U.-E., S.S.C.)
- Vancouver Clinic, Vancouver, WA (B.T.J)
| | - Kyndaron Reinier
- Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (B.K.T., B.T.J., K.R., C.T.,
A.U.-E., S.S.C.)
| | - Carmen Teodorescu
- Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (B.K.T., B.T.J., K.R., C.T.,
A.U.-E., S.S.C.)
| | - Audrey Uy-Evanado
- Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (B.K.T., B.T.J., K.R., C.T.,
A.U.-E., S.S.C.)
| | - Karen Gunson
- Department of Pathology, Oregon Health and Science University, Portland, OR (K.G.)
| | - Jonathan Jui
- Department of Emergency Medicine, Oregon Health and Science University, Portland, OR (J.J.)
| | - Sumeet S. Chugh
- Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (B.K.T., B.T.J., K.R., C.T.,
A.U.-E., S.S.C.)
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Abstract
Hypertrophic cardiomyopathy is a fascinating disease of marked heterogeneity. Hypertrophic cardiomyopathy was originally characterized by massive myocardial hypertrophy in the absence of known etiology, a dynamic left ventricular outflow obstruction, and increased risk of sudden death. It is now well accepted that multiple mutations in genes encoding for the cardiac sarcomere are responsible for the disease. Complex morphologic and pathophysiologic differences, disparate natural history studies, and novel treatment strategies underscore the challenge to the practicing cardiologist when faced with the management of the hypertrophic cardiomyopathy patient.
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Mortality Risk of Untreated Myosin-Binding Protein C–Related Hypertrophic Cardiomyopathy. J Am Coll Cardiol 2011; 58:2406-14. [DOI: 10.1016/j.jacc.2011.07.044] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Revised: 06/13/2011] [Accepted: 07/27/2011] [Indexed: 11/24/2022]
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Abstract
Hypertrophic cardiomyopathy (HCM) is the most-common monogenically inherited form of heart disease, characterized by thickening of the left ventricular wall, contractile dysfunction, and potentially fatal arrhythmias. HCM is also the most-common cause of sudden cardiac death in individuals younger than 35 years of age. Much progress has been made in the elucidation of the genetic basis of HCM, resulting in the identification of more than 900 individual mutations in over 20 genes. Interestingly, most of these genes encode sarcomeric proteins, such as myosin-7 (also known as cardiac muscle β-myosin heavy chain; MYH7), cardiac myosin-binding protein C (MYBPC3), and cardiac muscle troponin T (TNNT2). However, the molecular events that ultimately lead to the clinical phenotype of HCM are still unclear. We discuss several potential pathways, which include altered calcium cycling and sarcomeric calcium sensitivity, increased fibrosis, disturbed biomechanical stress sensing, and impaired cardiac energy homeostasis. An improved understanding of the pathological mechanisms involved will result in greater specificity and success of therapies for patients with HCM.
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Affiliation(s)
- Norbert Frey
- Department of Cardiology and Angiology, University of Kiel, Schittenhelmstrasse 12, 24105 Kiel, Germany
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van der Zwaag PA, van Tintelen JP. Counsel the genotype, treat the phenotype. Eur J Heart Fail 2011; 13:1159-60. [PMID: 21965524 DOI: 10.1093/eurjhf/hfr131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Christiaans I, Nannenberg EA, Dooijes D, Jongbloed RJE, Michels M, Postema PG, Majoor-Krakauer D, van den Wijngaard A, Mannens MMAM, van Tintelen JP, van Langen IM, Wilde AAM. Founder mutations in hypertrophic cardiomyopathy patients in the Netherlands. Neth Heart J 2011; 18:248-54. [PMID: 20505798 DOI: 10.1007/bf03091771] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
In this part of a series on cardiogenetic founder mutations in the Netherlands, we review the Dutch founder mutations in hypertrophic cardiomyopathy (HCM) patients. HCM is a common autosomal dominant genetic disease affecting at least one in 500 persons in the general population. Worldwide, most mutations in HCM patients are identified in genes encoding sarcomeric proteins, mainly in the myosin-binding protein C gene (MYBPC3, OMIM #600958) and the beta myosin heavy chain gene (MYH7, OMIM #160760). In the Netherlands, the great majority of mutations occur in the MYBPC3, involving mainly three Dutch founder mutations in the MYBPC3 gene, the c.2373_2374insG, the c.2864_2865delCT and the c.2827C>T mutation. In this review, we describe the genetics of HCM, the genotype-phenotype relation of Dutch founder MYBPC3 gene mutations, the prevalence and the geographic distribution of the Dutch founder mutations, and the consequences for genetic counselling and testing. (Neth Heart J 2010;18:248-54.).
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Affiliation(s)
- I Christiaans
- Department of Clinical Genetics, Academic Medical Centre, Amsterdam, the Netherlands These authors contributed equally
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