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Topriceanu CC, Pereira AC, Moon JC, Captur G, Ho CY. Meta-Analysis of Penetrance and Systematic Review on Transition to Disease in Genetic Hypertrophic Cardiomyopathy. Circulation 2024; 149:107-123. [PMID: 37929589 PMCID: PMC10775968 DOI: 10.1161/circulationaha.123.065987] [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: 06/14/2023] [Accepted: 10/27/2023] [Indexed: 11/07/2023]
Abstract
BACKGROUND Hypertrophic cardiomyopathy (HCM) is characterized by unexplained left ventricular hypertrophy and is classically caused by pathogenic or likely pathogenic variants (P/LP) in genes encoding sarcomere proteins. Not all subclinical variant carriers will manifest clinically overt disease because penetrance (proportion of sarcomere or sarcomere-related P/LP variant carriers who develop disease) is variable, age dependent, and not reliably predicted. METHODS A systematic search of the literature was performed. We used random-effects generalized linear mixed model meta-analyses to contrast the cross-sectional prevalence and penetrance of sarcomere or sarcomere-related genes in 2 different contexts: clinically-based studies on patients and families with HCM versus population or community-based studies. Longitudinal family/clinical studies were additionally analyzed to investigate the rate of phenotypic conversion from subclinical to overt HCM during follow-up. RESULTS In total, 455 full-text manuscripts and articles were assessed. In family/clinical studies, the prevalence of sarcomere variants in patients diagnosed with HCM was 34%. The penetrance across all genes in nonproband relatives carrying P/LP variants identified during cascade screening was 57% (95% CI, 52%-63%), and the mean age at HCM diagnosis was 38 years (95% CI, 36%-40%). Penetrance varied from ≈32% for MYL3 (myosin light chain 3) to ≈55% for MYBPC3 (myosin-binding protein C3), ≈60% for TNNT2 (troponin T2) and TNNI3 (troponin I3), and ≈65% for MYH7 (myosin heavy chain 7). Population-based genetic studies demonstrate that P/LP sarcomere variants are present in the background population but at a low prevalence of <1%. The penetrance of HCM in incidentally identified P/LP variant carriers was also substantially lower at ≈11%, ranging from 0% in Atherosclerosis Risk in Communities to 18% in UK Biobank. In longitudinal family studies, the pooled phenotypic conversion across all genes was 15% over an average of ≈8 years of follow-up, starting from a mean of ≈16 years of age. However, short-term gene-specific phenotypic conversion varied between ≈12% for MYBPC3 and ≈23% for MYH7. CONCLUSIONS The penetrance of P/LP variants is highly variable and influenced by currently undefined and context-dependent genetic and environmental factors. Additional longitudinal studies are needed to improve our understanding of true lifetime penetrance in families and in the community and to identify drivers of the transition from subclinical to overt HCM.
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Affiliation(s)
- Constantin-Cristian Topriceanu
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA (C.-C.T., A.C.P., C.Y.H.). UCL Institute of Cardiovascular Science (C.-C.T., J.C.M., G.C.) and UCL MRC Unit for Lifelong Health and Ageing (G.C.), University College London, UK. Cardiac MRI Unit, Barts Heart Centre, West Smithfield, London, UK (C.-C.T., J.C.M.). The Royal Free Hospital, Centre for Inherited Heart Muscle Conditions, Cardiology Department, Hampstead, London, UK (G.C.)
| | - Alexandre C. Pereira
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA (C.-C.T., A.C.P., C.Y.H.). UCL Institute of Cardiovascular Science (C.-C.T., J.C.M., G.C.) and UCL MRC Unit for Lifelong Health and Ageing (G.C.), University College London, UK. Cardiac MRI Unit, Barts Heart Centre, West Smithfield, London, UK (C.-C.T., J.C.M.). The Royal Free Hospital, Centre for Inherited Heart Muscle Conditions, Cardiology Department, Hampstead, London, UK (G.C.)
| | - James C. Moon
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA (C.-C.T., A.C.P., C.Y.H.). UCL Institute of Cardiovascular Science (C.-C.T., J.C.M., G.C.) and UCL MRC Unit for Lifelong Health and Ageing (G.C.), University College London, UK. Cardiac MRI Unit, Barts Heart Centre, West Smithfield, London, UK (C.-C.T., J.C.M.). The Royal Free Hospital, Centre for Inherited Heart Muscle Conditions, Cardiology Department, Hampstead, London, UK (G.C.)
| | - Gabriella Captur
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA (C.-C.T., A.C.P., C.Y.H.). UCL Institute of Cardiovascular Science (C.-C.T., J.C.M., G.C.) and UCL MRC Unit for Lifelong Health and Ageing (G.C.), University College London, UK. Cardiac MRI Unit, Barts Heart Centre, West Smithfield, London, UK (C.-C.T., J.C.M.). The Royal Free Hospital, Centre for Inherited Heart Muscle Conditions, Cardiology Department, Hampstead, London, UK (G.C.)
| | - Carolyn Y. Ho
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA (C.-C.T., A.C.P., C.Y.H.). UCL Institute of Cardiovascular Science (C.-C.T., J.C.M., G.C.) and UCL MRC Unit for Lifelong Health and Ageing (G.C.), University College London, UK. Cardiac MRI Unit, Barts Heart Centre, West Smithfield, London, UK (C.-C.T., J.C.M.). The Royal Free Hospital, Centre for Inherited Heart Muscle Conditions, Cardiology Department, Hampstead, London, UK (G.C.)
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Chumakova OS, Baklanova TN, Milovanova NV, Zateyshchikov DA. Hypertrophic Cardiomyopathy in Underrepresented Populations: Clinical and Genetic Landscape Based on a Russian Single-Center Cohort Study. Genes (Basel) 2023; 14:2042. [PMID: 38002985 PMCID: PMC10671745 DOI: 10.3390/genes14112042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/30/2023] [Accepted: 11/02/2023] [Indexed: 11/26/2023] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a common inherited cardiac disorder characterized by marked clinical and genetic heterogeneity. Ethnic groups underrepresented in studies may have distinctive characteristics. We sought to evaluate the clinical and genetic landscape of Russian HCM patients. A total of 193 patients (52% male; 95% Eastern Slavic origin; median age 56 years) were clinically evaluated, including genetic testing, and prospectively followed to document outcomes. As a result, 48% had obstructive HCM, 25% had HCM in family, 21% were asymptomatic, and 68% had comorbidities. During 2.8 years of follow-up, the all-cause mortality rate was 2.86%/year. A total of 5.7% received an implantable cardioverter-defibrillator (ICD), and 21% had septal reduction therapy. A sequencing analysis of 176 probands identified 64 causative variants in 66 patients (38%); recurrent variants were MYBPC3 p.Q1233* (8), MYBPC3 p.R346H (2), MYH7 p.A729P (2), TPM1 p.Q210R (3), and FLNC p.H1834Y (2); 10 were multiple variant carriers (5.7%); 5 had non-sarcomeric HCM, ALPK3, TRIM63, and FLNC. Thin filament variant carriers had a worse prognosis for heart failure (HR = 7.9, p = 0.007). In conclusion, in the Russian HCM population, the low use of ICD and relatively high mortality should be noted by clinicians; some distinct recurrent variants are suspected to have a founder effect; and family studies on some rare variants enriched worldwide knowledge in HCM.
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Affiliation(s)
- Olga S. Chumakova
- Moscow Healthcare Department, City Clinical Hospital 17, 119620 Moscow, Russia; (T.N.B.); (D.A.Z.)
- E.I. Chazov National Medical Research Center for Cardiology, 121552 Moscow, Russia
| | - Tatiana N. Baklanova
- Moscow Healthcare Department, City Clinical Hospital 17, 119620 Moscow, Russia; (T.N.B.); (D.A.Z.)
| | | | - Dmitry A. Zateyshchikov
- Moscow Healthcare Department, City Clinical Hospital 17, 119620 Moscow, Russia; (T.N.B.); (D.A.Z.)
- E.I. Chazov National Medical Research Center for Cardiology, 121552 Moscow, Russia
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Sepp R, Hategan L, Csányi B, Borbás J, Tringer A, Pálinkás ED, Nagy V, Takács H, Latinovics D, Nyolczas N, Pálinkás A, Faludi R, Rábai M, Szabó GT, Czuriga D, Balogh L, Halmosi R, Borbély A, Habon T, Hegedűs Z, Nagy I. The Genetic Architecture of Hypertrophic Cardiomyopathy in Hungary: Analysis of 242 Patients with a Panel of 98 Genes. Diagnostics (Basel) 2022; 12:diagnostics12051132. [PMID: 35626289 PMCID: PMC9139509 DOI: 10.3390/diagnostics12051132] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 04/24/2022] [Accepted: 04/29/2022] [Indexed: 12/03/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a primary disease of the myocardium most commonly caused by mutations in sarcomeric genes. We aimed to perform a nationwide large-scale genetic analysis of a previously unreported, representative HCM cohort in Hungary. A total of 242 consecutive HCM index patients (127 men, 44 ± 11 years) were studied with next generation sequencing using a custom-designed gene-panel comprising 98 cardiomyopathy-related genes. A total of 90 patients (37%) carried pathogenic/likely pathogenic (P/LP) variants. The percentage of patients with P/LP variants in genes with definitive evidence for HCM association was 93%. Most of the patients with P/LP variants had mutations in MYBPC3 (55 pts, 61%) and in MYH7 (21 pts, 23%). Double P/LP variants were present in four patients (1.7%). P/LP variants in other genes could be detected in ≤3% of patients. Of the patients without P/LP variants, 46 patients (19%) carried a variant of unknown significance. Non-HCM P/LP variants were identified in six patients (2.5%), with two in RAF1 (p.Leu633Val, p.Ser257Leu) and one in DES (p.Arg406Trp), FHL1 (p.Glu96Ter), TTN (p.Lys23480fs), and in the mitochondrial genome (m.3243A>G). Frameshift, nonsense, and splice-variants made up 82% of all P/LP MYBPC3 variants. In all the other genes, missense mutations were the dominant form of variants. The MYBPC3 p.Gln1233Ter, the MYBPC3 p.Pro955ArgfsTer95, and the MYBPC3 p.Ser593ProfsTer11 variants were identified in 12, 7, and 13 patients, respectively. These three variants made up 36% of all patients with identified P/LP variants, raising the possibility of a possible founder effect for these mutations. Similar to other HCM populations, the MYBPC3 and the MYH7 genes seemed to be the most frequently affected genes in Hungarian HCM patients. The high prevalence of three MYBPC3 mutations raises the possibility of a founder effect in our HCM cohort.
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Affiliation(s)
- Róbert Sepp
- Division of Non-Invasive Cardiology, Department of Internal Medicine, Faculty of Medicine, University of Szeged, Semmelweis u. 8, H-6725 Szeged, Hungary; (L.H.); (B.C.); (J.B.); (A.T.); (E.D.P.); (V.N.); (H.T.)
- Correspondence: ; Tel.: +36-30-267-5845; Fax: +36-62-545-820
| | - Lidia Hategan
- Division of Non-Invasive Cardiology, Department of Internal Medicine, Faculty of Medicine, University of Szeged, Semmelweis u. 8, H-6725 Szeged, Hungary; (L.H.); (B.C.); (J.B.); (A.T.); (E.D.P.); (V.N.); (H.T.)
| | - Beáta Csányi
- Division of Non-Invasive Cardiology, Department of Internal Medicine, Faculty of Medicine, University of Szeged, Semmelweis u. 8, H-6725 Szeged, Hungary; (L.H.); (B.C.); (J.B.); (A.T.); (E.D.P.); (V.N.); (H.T.)
| | - János Borbás
- Division of Non-Invasive Cardiology, Department of Internal Medicine, Faculty of Medicine, University of Szeged, Semmelweis u. 8, H-6725 Szeged, Hungary; (L.H.); (B.C.); (J.B.); (A.T.); (E.D.P.); (V.N.); (H.T.)
| | - Annamária Tringer
- Division of Non-Invasive Cardiology, Department of Internal Medicine, Faculty of Medicine, University of Szeged, Semmelweis u. 8, H-6725 Szeged, Hungary; (L.H.); (B.C.); (J.B.); (A.T.); (E.D.P.); (V.N.); (H.T.)
| | - Eszter Dalma Pálinkás
- Division of Non-Invasive Cardiology, Department of Internal Medicine, Faculty of Medicine, University of Szeged, Semmelweis u. 8, H-6725 Szeged, Hungary; (L.H.); (B.C.); (J.B.); (A.T.); (E.D.P.); (V.N.); (H.T.)
| | - Viktória Nagy
- Division of Non-Invasive Cardiology, Department of Internal Medicine, Faculty of Medicine, University of Szeged, Semmelweis u. 8, H-6725 Szeged, Hungary; (L.H.); (B.C.); (J.B.); (A.T.); (E.D.P.); (V.N.); (H.T.)
| | - Hedvig Takács
- Division of Non-Invasive Cardiology, Department of Internal Medicine, Faculty of Medicine, University of Szeged, Semmelweis u. 8, H-6725 Szeged, Hungary; (L.H.); (B.C.); (J.B.); (A.T.); (E.D.P.); (V.N.); (H.T.)
| | - Dóra Latinovics
- SeqOmics Biotechnology Ltd., Vállalkozók útja 7, H-6782 Mórahalom, Hungary; (D.L.); (I.N.)
| | - Noémi Nyolczas
- Gottsegen National Cardiovascular Center, Haller u. 29, H-1096 Budapest, Hungary;
- Military Hospital-State Health Center, Róbert Károly körút 44, H-1134 Budapest, Hungary
| | - Attila Pálinkás
- Elisabeth Hospital, Dr. Imre József u. 9, H-6800 Hódmezővásárhely, Hungary;
| | - Réka Faludi
- Heart Institute, Medical School, University of Pécs, Ifjúság útja 13, H-7624 Pécs, Hungary;
| | - Miklós Rábai
- Division of Cardiology, First Department of Medicine, Medical School, University of Pécs, Ifjúság útja 13, H-7624 Pécs, Hungary; (M.R.); (R.H.); (T.H.)
| | - Gábor Tamás Szabó
- Division of Cardiology and Division of Clinical Physiology, Department of Cardiology, University of Debrecen, Móricz Zsigmond körút 22, H-4032 Debrecen, Hungary; (G.T.S.); (D.C.); (L.B.); (A.B.)
| | - Dániel Czuriga
- Division of Cardiology and Division of Clinical Physiology, Department of Cardiology, University of Debrecen, Móricz Zsigmond körút 22, H-4032 Debrecen, Hungary; (G.T.S.); (D.C.); (L.B.); (A.B.)
| | - László Balogh
- Division of Cardiology and Division of Clinical Physiology, Department of Cardiology, University of Debrecen, Móricz Zsigmond körút 22, H-4032 Debrecen, Hungary; (G.T.S.); (D.C.); (L.B.); (A.B.)
| | - Róbert Halmosi
- Division of Cardiology, First Department of Medicine, Medical School, University of Pécs, Ifjúság útja 13, H-7624 Pécs, Hungary; (M.R.); (R.H.); (T.H.)
- Szentágothai Research Centre, University of Pécs, Ifjúság útja 20, H-7624 Pécs, Hungary
| | - Attila Borbély
- Division of Cardiology and Division of Clinical Physiology, Department of Cardiology, University of Debrecen, Móricz Zsigmond körút 22, H-4032 Debrecen, Hungary; (G.T.S.); (D.C.); (L.B.); (A.B.)
| | - Tamás Habon
- Division of Cardiology, First Department of Medicine, Medical School, University of Pécs, Ifjúság útja 13, H-7624 Pécs, Hungary; (M.R.); (R.H.); (T.H.)
| | - Zoltán Hegedűs
- Institute of Biophysics, Biological Research Centre, Eötvös Loránd Research Network, Temesvári krt. 62, H-6726 Szeged, Hungary;
- Department of Biochemistry and Medical Chemistry, Medical School, University of Pécs, Szigeti út 12, H-7624 Pécs, Hungary
| | - István Nagy
- SeqOmics Biotechnology Ltd., Vállalkozók útja 7, H-6782 Mórahalom, Hungary; (D.L.); (I.N.)
- Institute of Biochemistry, Biological Research Center, Eötvös Loránd Research Network, Temesvári krt. 62, H-6726 Szeged, Hungary
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Lamounier Junior A, Guitián González A, Rodríguez Vilela A, Repáraz Andrade A, Rubio Alcaide Á, Berta Sousa A, Benito López C, Alonso García D, Fernández Ferro G, Cruz I, Cárdenas Reyes IJ, Salazar-Mendiguchía García J, Larrañaga-Moreira JM, Ochoa JP, Palomino-Doza J, de la Higuera Romero L, Nicolás Cicerchia M, Restrepo Córdoba MA, Peña-Peña ML, Noël Brögger M, Loureiro M, Mogollón Jiménez MV, Bilbao Quesada R, Franco Gutiérrez R, García Hernández S, Ripoll-Vera T, Fernández X, Azevedo O, García Pavía P, Lopes LR, Ortiz M, Brito D, Barriales-Villa R, Monserrat Iglesias L. Correlación genotipo-fenotipo en miocardiopatía hipertrófica: un estudio multicéntrico en Portugal y España sobre la variante p.Arg21Leu de TPM1. Rev Esp Cardiol 2022. [DOI: 10.1016/j.recesp.2020.12.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
Hypertrophic cardiomyopathy (HCM) is a genetic disease of the myocardium characterized by a hypertrophic left ventricle with a preserved or increased ejection fraction. Cardiac hypertrophy is often asymmetrical, which is associated with left ventricular outflow tract obstruction. Myocyte hypertrophy, disarray, and myocardial fibrosis constitute the histological features of HCM. HCM is a relatively benign disease but an important cause of sudden cardiac death in the young and heart failure in the elderly. Pathogenic variants (PVs) in genes encoding protein constituents of the sarcomeres are the main causes of HCM. PVs exhibit a gradient of effect sizes, as reflected in their penetrance and variable phenotypic expression of HCM. MYH7 and MYBPC3, encoding β-myosin heavy chain and myosin binding protein C, respectively, are the two most common causal genes and responsible for ≈40% of all HCM cases but a higher percentage of HCM in large families. PVs in genes encoding protein components of the thin filaments are responsible for ≈5% of the HCM cases. Whereas pathogenicity of the genetic variants in large families has been firmly established, ascertainment causality of the PVs in small families and sporadic cases is challenging. In the latter category, PVs are best considered as probabilistic determinants of HCM. Deciphering the genetic basis of HCM has enabled routine genetic testing and has partially elucidated the underpinning mechanism of HCM as increased number of the myosin molecules that are strongly bound to actin. The discoveries have led to the development of mavacamten that targets binding of the myosin molecule to actin filaments and imparts beneficial clinical effects. In the coming years, the yield of the genetic testing is expected to be improved and the so-called missing causal gene be identified. The advances are also expected to enable development of additional specific therapies and editing of the mutations in HCM.
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Affiliation(s)
- A J Marian
- Center for Cardiovascular Genetics, Institute of Molecular Medicine and Department of Medicine, University of Texas Health Sciences Center at Houston
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Genotype-phenotype correlations in hypertrophic cardiomyopathy: a multicenter study in Portugal and Spain of the TPM1 p.Arg21Leu variant. ACTA ACUST UNITED AC 2021; 75:242-250. [PMID: 33642254 DOI: 10.1016/j.rec.2021.01.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 12/18/2020] [Indexed: 11/23/2022]
Abstract
INTRODUCTION AND OBJECTIVES TPM1 is one of the main hypertrophic cardiomyopathy (HCM) genes. Clinical information on carriers is relatively scarce, limiting the interpretation of genetic findings in individual patients. Our aim was to establish genotype-phenotype correlations of the TPM1 p.Arg21Leu variant in a serie of pedigrees. METHODS TPM1 was evaluated by next-generation sequencing in 10 561 unrelated probands with inherited heart diseases. Familial genetic screening was performed by the Sanger method. We analyzed TPM1 p.Arg21Leu pedigrees for cosegregation, clinical characteristics, and outcomes. We also estimated the geographical distribution of the carrier families in Portugal and Spain. RESULTS The TPM1 p.Arg21Leu variant was identified in 25/4099 (0.61%) HCM-cases, and was absent in 6462 control individuals with other inherited cardiac phenotypes (P<.0001). In total, 83 carriers (31 probands) were identified. The combined LOD score for familial cosegregation was 3.95. The cumulative probability of diagnosis in carriers was 50% at the age of 50 years for males, and was 25% in female carriers. At the age of 70 years, 17% of males and 46% of female carriers were unaffected. Mean maximal left ventricular wall thickness was 21.4 ±7.65mm. Calculated HCM sudden death risk was low in 34 carriers (77.5%), intermediated in 8 (18%), and high in only 2 (4.5%). Survival free of cardiovascular death or heart transplant was 87.5% at 50 years. Six percent of carriers were homozygous and 18% had an additional variant. Family origin was concentrated in Galicia, Extremadura, and northern Portugal, suggesting a founder effect. CONCLUSIONS TPM1 p.Arg21Leu is a pathogenic HCM variant associated with late-onset/incomplete penetrance and a generally favorable prognosis.
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Pua CJ, Tham N, Chin CW, Walsh R, Khor CC, Toepfer CN, Repetti GG, Garfinkel AC, Ewoldt JK, Cloonan P, Chen CS, Lim SQ, Cai J, Loo LY, Kong SC, Chiang CW, Whiffin N, de Marvao A, Lio PM, Hii AA, Yang CX, Le TT, Bylstra Y, Lim WK, Teo JX, Padilha K, Silva GV, Pan B, Govind R, Buchan RJ, Barton PJ, Tan P, Foo R, Yip JW, Wong RC, Chan WX, Pereira AC, Tang HC, Jamuar SS, Ware JS, Seidman JG, Seidman CE, Cook SA. Genetic Studies of Hypertrophic Cardiomyopathy in Singaporeans Identify Variants in TNNI3 and TNNT2 That Are Common in Chinese Patients. CIRCULATION. GENOMIC AND PRECISION MEDICINE 2020; 13:424-434. [PMID: 32815737 PMCID: PMC7676617 DOI: 10.1161/circgen.119.002823] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 07/27/2020] [Indexed: 11/16/2022]
Abstract
BACKGROUND To assess the genetic architecture of hypertrophic cardiomyopathy (HCM) in patients of predominantly Chinese ancestry. METHODS We sequenced HCM disease genes in Singaporean patients (n=224) and Singaporean controls (n=3634), compared findings with additional populations and White HCM cohorts (n=6179), and performed in vitro functional studies. RESULTS Singaporean HCM patients had significantly fewer confidently interpreted HCM disease variants (pathogenic/likely pathogenic: 18%, P<0.0001) but an excess of variants of uncertain significance (24%, P<0.0001), as compared to Whites (pathogenic/likely pathogenic: 31%, excess of variants of uncertain significance: 7%). Two missense variants in thin filament encoding genes were commonly seen in Singaporean HCM (TNNI3:p.R79C, disease allele frequency [AF]=0.018; TNNT2:p.R286H, disease AF=0.022) and are enriched in Singaporean HCM when compared with Asian controls (TNNI3:p.R79C, Singaporean controls AF=0.0055, P=0.0057, genome aggregation database-East Asian AF=0.0062, P=0.0086; TNNT2:p.R286H, Singaporean controls AF=0.0017, P<0.0001, genome aggregation database-East Asian AF=0.0009, P<0.0001). Both these variants have conflicting annotations in ClinVar and are of low penetrance (TNNI3:p.R79C, 0.7%; TNNT2:p.R286H, 2.7%) but are predicted to be deleterious by computational tools. In population controls, TNNI3:p.R79C carriers had significantly thicker left ventricular walls compared with noncarriers while its etiological fraction is limited (0.70 [95% CI, 0.35-0.86]) and thus TNNI3:p.R79C is considered variant of uncertain significance. Mutant TNNT2:p.R286H iPSC-CMs (induced pluripotent stem cells derived cardiomyocytes) show hypercontractility, increased metabolic requirements, and cellular hypertrophy and the etiological fraction (0.93 [95% CI, 0.83-0.97]) support the likely pathogenicity of TNNT2:p.R286H. CONCLUSIONS As compared with Whites, Chinese HCM patients commonly have low penetrance risk alleles in TNNT2 or TNNI3 but exhibit few clinically actionable HCM variants overall. This highlights the need for greater study of HCM genetics in non-White populations.
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Affiliation(s)
- Chee Jian Pua
- National Heart Centre Singapore (C.J.P., N.T., C.W.L.C., S.Q.L., S.C.K., P.M.L., A.A.H., C.X.Y., T.T.L., H.C.T., S.A.C.)
- Yong Loo Lin School of Medicine, National University Singapore (C.J.P., L.Y.L.)
| | - Nevin Tham
- National Heart Centre Singapore (C.J.P., N.T., C.W.L.C., S.Q.L., S.C.K., P.M.L., A.A.H., C.X.Y., T.T.L., H.C.T., S.A.C.)
| | - Calvin W.L. Chin
- National Heart Centre Singapore (C.J.P., N.T., C.W.L.C., S.Q.L., S.C.K., P.M.L., A.A.H., C.X.Y., T.T.L., H.C.T., S.A.C.)
- Duke-National University of Singapore Medical School (C.W.L.C., J.C., S.S.J., S.A.C.)
| | - Roddy Walsh
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, the Netherlands (R.W.)
| | | | - Christopher N. Toepfer
- Department of Genetics, Harvard Medical School, Boston, MA (C.N.T., G.G.R., A.C.G., K.P., G.V.S., A.C.P., J.G.S., C.E.S.)
- Radcliffe Department of Medicine, University of Oxford, United Kingdom (C.N.T.)
| | - Giuliana G. Repetti
- Department of Genetics, Harvard Medical School, Boston, MA (C.N.T., G.G.R., A.C.G., K.P., G.V.S., A.C.P., J.G.S., C.E.S.)
| | - Amanda C. Garfinkel
- Department of Genetics, Harvard Medical School, Boston, MA (C.N.T., G.G.R., A.C.G., K.P., G.V.S., A.C.P., J.G.S., C.E.S.)
| | - Jourdan K. Ewoldt
- Department of Biomedical Engineering, Boston University, MA (J.K.E., P.C., C.S.C.)
| | - Paige Cloonan
- Department of Biomedical Engineering, Boston University, MA (J.K.E., P.C., C.S.C.)
| | - Christopher S. Chen
- Department of Biomedical Engineering, Boston University, MA (J.K.E., P.C., C.S.C.)
| | - Shi Qi Lim
- National Heart Centre Singapore (C.J.P., N.T., C.W.L.C., S.Q.L., S.C.K., P.M.L., A.A.H., C.X.Y., T.T.L., H.C.T., S.A.C.)
| | - Jiashen Cai
- Duke-National University of Singapore Medical School (C.W.L.C., J.C., S.S.J., S.A.C.)
| | - Li Yang Loo
- Yong Loo Lin School of Medicine, National University Singapore (C.J.P., L.Y.L.)
| | - Siew Ching Kong
- National Heart Centre Singapore (C.J.P., N.T., C.W.L.C., S.Q.L., S.C.K., P.M.L., A.A.H., C.X.Y., T.T.L., H.C.T., S.A.C.)
| | - Charleston W.K. Chiang
- Center for Genetic Epidemiology, University of Southern California (C.W.K.C.)
- Center for Neurobehavioral Genetics, University of California, Los Angeles (C.W.K.C.)
| | - Nicola Whiffin
- Cardiovascular Research Center, Royal Brompton Hospital, London, United Kingdom (N.W., A.d.M., R.G., R.J.B., P.J.R.B., J.S.W., S.A.C.)
- National Heart and Lung Institute, Imperial College London, United Kingdom (N.W., A.d.M., R.G., R.J.B., P.J.R.B., J.S.W., S.A.C.)
| | - Antonio de Marvao
- Cardiovascular Research Center, Royal Brompton Hospital, London, United Kingdom (N.W., A.d.M., R.G., R.J.B., P.J.R.B., J.S.W., S.A.C.)
- National Heart and Lung Institute, Imperial College London, United Kingdom (N.W., A.d.M., R.G., R.J.B., P.J.R.B., J.S.W., S.A.C.)
| | - Pei Min Lio
- National Heart Centre Singapore (C.J.P., N.T., C.W.L.C., S.Q.L., S.C.K., P.M.L., A.A.H., C.X.Y., T.T.L., H.C.T., S.A.C.)
| | - An An Hii
- National Heart Centre Singapore (C.J.P., N.T., C.W.L.C., S.Q.L., S.C.K., P.M.L., A.A.H., C.X.Y., T.T.L., H.C.T., S.A.C.)
| | - Cheng Xi Yang
- National Heart Centre Singapore (C.J.P., N.T., C.W.L.C., S.Q.L., S.C.K., P.M.L., A.A.H., C.X.Y., T.T.L., H.C.T., S.A.C.)
| | - Thu Thao Le
- National Heart Centre Singapore (C.J.P., N.T., C.W.L.C., S.Q.L., S.C.K., P.M.L., A.A.H., C.X.Y., T.T.L., H.C.T., S.A.C.)
| | - Yasmin Bylstra
- SingHealth/Duke-NUS Precision Medicine Inst, Singapore (Y.B., W.K.L., J.X.T., P.T., S.S.J.)
| | - Weng Khong Lim
- SingHealth/Duke-NUS Precision Medicine Inst, Singapore (Y.B., W.K.L., J.X.T., P.T., S.S.J.)
| | - Jing Xian Teo
- SingHealth/Duke-NUS Precision Medicine Inst, Singapore (Y.B., W.K.L., J.X.T., P.T., S.S.J.)
| | - Kallyandra Padilha
- Department of Genetics, Harvard Medical School, Boston, MA (C.N.T., G.G.R., A.C.G., K.P., G.V.S., A.C.P., J.G.S., C.E.S.)
- Laboratory of Genetics and Molecular Cardiology, Heart Institute (InCor)-University of São Paulo Medical School, Brazil (K.P., G.V.S., A.C.P.)
| | - Gabriela V. Silva
- Department of Genetics, Harvard Medical School, Boston, MA (C.N.T., G.G.R., A.C.G., K.P., G.V.S., A.C.P., J.G.S., C.E.S.)
- Laboratory of Genetics and Molecular Cardiology, Heart Institute (InCor)-University of São Paulo Medical School, Brazil (K.P., G.V.S., A.C.P.)
| | - Bangfen Pan
- Cardiovascular Research Institute, National University Health System, Singapore (B.P., R.F.)
| | - Risha Govind
- Cardiovascular Research Center, Royal Brompton Hospital, London, United Kingdom (N.W., A.d.M., R.G., R.J.B., P.J.R.B., J.S.W., S.A.C.)
- National Heart and Lung Institute, Imperial College London, United Kingdom (N.W., A.d.M., R.G., R.J.B., P.J.R.B., J.S.W., S.A.C.)
| | - Rachel J. Buchan
- Cardiovascular Research Center, Royal Brompton Hospital, London, United Kingdom (N.W., A.d.M., R.G., R.J.B., P.J.R.B., J.S.W., S.A.C.)
- National Heart and Lung Institute, Imperial College London, United Kingdom (N.W., A.d.M., R.G., R.J.B., P.J.R.B., J.S.W., S.A.C.)
| | - Paul J.R. Barton
- Cardiovascular Research Center, Royal Brompton Hospital, London, United Kingdom (N.W., A.d.M., R.G., R.J.B., P.J.R.B., J.S.W., S.A.C.)
- National Heart and Lung Institute, Imperial College London, United Kingdom (N.W., A.d.M., R.G., R.J.B., P.J.R.B., J.S.W., S.A.C.)
| | - Patrick Tan
- Genome Institute of Singapore (C.C.K., P.T., R.F.)
- SingHealth/Duke-NUS Precision Medicine Inst, Singapore (Y.B., W.K.L., J.X.T., P.T., S.S.J.)
| | - Roger Foo
- Genome Institute of Singapore (C.C.K., P.T., R.F.)
- Cardiovascular Research Institute, National University Health System, Singapore (B.P., R.F.)
| | - James W.L. Yip
- Cardiology Department, National University Heart Centre, Singapore (J.W.L.Y., R.C.C.W., W.X.C.)
| | - Raymond C.C. Wong
- Cardiology Department, National University Heart Centre, Singapore (J.W.L.Y., R.C.C.W., W.X.C.)
| | - Wan Xian Chan
- Cardiology Department, National University Heart Centre, Singapore (J.W.L.Y., R.C.C.W., W.X.C.)
| | - Alexandre C. Pereira
- Department of Genetics, Harvard Medical School, Boston, MA (C.N.T., G.G.R., A.C.G., K.P., G.V.S., A.C.P., J.G.S., C.E.S.)
- Laboratory of Genetics and Molecular Cardiology, Heart Institute (InCor)-University of São Paulo Medical School, Brazil (K.P., G.V.S., A.C.P.)
| | - Hak Chiaw Tang
- National Heart Centre Singapore (C.J.P., N.T., C.W.L.C., S.Q.L., S.C.K., P.M.L., A.A.H., C.X.Y., T.T.L., H.C.T., S.A.C.)
| | - Saumya Shekhar Jamuar
- Duke-National University of Singapore Medical School (C.W.L.C., J.C., S.S.J., S.A.C.)
- National Heart and Lung Institute, Imperial College London, United Kingdom (N.W., A.d.M., R.G., R.J.B., P.J.R.B., J.S.W., S.A.C.)
- KK Women’s and Children’s Hospital, Singapore (S.S.J.)
- SingHealth Duke-NUS Genomic Medicine Centre, Singapore (S.S.J.)
| | - James S. Ware
- Cardiovascular Research Center, Royal Brompton Hospital, London, United Kingdom (N.W., A.d.M., R.G., R.J.B., P.J.R.B., J.S.W., S.A.C.)
- National Heart and Lung Institute, Imperial College London, United Kingdom (N.W., A.d.M., R.G., R.J.B., P.J.R.B., J.S.W., S.A.C.)
| | - Jonathan G. Seidman
- Department of Genetics, Harvard Medical School, Boston, MA (C.N.T., G.G.R., A.C.G., K.P., G.V.S., A.C.P., J.G.S., C.E.S.)
| | - Christine E. Seidman
- Department of Genetics, Harvard Medical School, Boston, MA (C.N.T., G.G.R., A.C.G., K.P., G.V.S., A.C.P., J.G.S., C.E.S.)
- Cardiovascular Division, Brigham and Women’s Hospital, Howard Hughes Medical Institute, Boston, MA (C.E.S.)
| | - Stuart A. Cook
- National Heart Centre Singapore (C.J.P., N.T., C.W.L.C., S.Q.L., S.C.K., P.M.L., A.A.H., C.X.Y., T.T.L., H.C.T., S.A.C.)
- Duke-National University of Singapore Medical School (C.W.L.C., J.C., S.S.J., S.A.C.)
- Cardiovascular Research Center, Royal Brompton Hospital, London, United Kingdom (N.W., A.d.M., R.G., R.J.B., P.J.R.B., J.S.W., S.A.C.)
- National Heart and Lung Institute, Imperial College London, United Kingdom (N.W., A.d.M., R.G., R.J.B., P.J.R.B., J.S.W., S.A.C.)
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8
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Arif M, Nabavizadeh P, Song T, Desai D, Singh R, Bazrafshan S, Kumar M, Wang Y, Gilbert RJ, Dhandapany PS, Becker RC, Kranias EG, Sadayappan S. Genetic, clinical, molecular, and pathogenic aspects of the South Asian-specific polymorphic MYBPC3 Δ25bp variant. Biophys Rev 2020; 12:1065-1084. [PMID: 32656747 PMCID: PMC7429610 DOI: 10.1007/s12551-020-00725-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 07/03/2020] [Indexed: 02/06/2023] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a cardiac genetic disease characterized by ventricular enlargement, diastolic dysfunction, and increased risk for sudden cardiac death. Sarcomeric genetic defects are the predominant known cause of HCM. In particular, mutations in the myosin-binding protein C gene (MYBPC3) are associated with ~ 40% of all HCM cases in which a genetic basis has been established. A decade ago, our group reported a 25-base pair deletion in intron 32 of MYBPC3 (MYBPC3Δ25bp) that is uniquely prevalent in South Asians and is associated with autosomal dominant cardiomyopathy. Although our studies suggest that this deletion results in left ventricular dysfunction, cardiomyopathies, and heart failure, the precise mechanism by which this variant predisposes to heart disease remains unclear. Increasingly appreciated, however, is the contribution of secondary risk factors, additional mutations, and lifestyle choices in augmenting or modifying the HCM phenotype in MYBPC3Δ25bp carriers. Therefore, the goal of this review article is to summarize the current research dedicated to understanding the molecular pathophysiology of HCM in South Asians with the MYBPC3Δ25bp variant. An emphasis is to review the latest techniques currently applied to explore the MYBPC3Δ25bp pathogenesis and to provide a foundation for developing new diagnostic strategies and advances in therapeutics.
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Affiliation(s)
- Mohammed Arif
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA.
| | - Pooneh Nabavizadeh
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
| | - Taejeong Song
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
| | - Darshini Desai
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
| | - Rohit Singh
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
| | - Sholeh Bazrafshan
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
| | - Mohit Kumar
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
| | - Yigang Wang
- Department of Pathology and Laboratory Medicine, University of Cincinnati, College of Medicine, Cincinnati, OH, 45267, USA
| | - Richard J Gilbert
- Research Service, Providence VA Medical Center, Providence, RI, 02908, USA
| | - Perundurai S Dhandapany
- Centre for Cardiovascular Biology and Disease, Institute for Stem Cell Biology and Regenerative Medicine (inStem), Bangalore, India
- The Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
- Department of Medicine, Oregon Health and Science University, Portland, OR, USA
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR, USA
| | - Richard C Becker
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
| | - Evangelia G Kranias
- Department of Pharmacology and Systems Physiology, University of Cincinnati, College of Medicine, Cincinnati, OH, 45267, USA
| | - Sakthivel Sadayappan
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
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9
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Lehmonen L, Jalanko M, Tarkiainen M, Kaasalainen T, Kuusisto J, Lauerma K, Savolainen S. Rotation and torsion of the left ventricle with cardiovascular magnetic resonance tagging: comparison of two analysis methods. BMC Med Imaging 2020; 20:73. [PMID: 32611329 PMCID: PMC7329530 DOI: 10.1186/s12880-020-00473-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 06/19/2020] [Indexed: 11/24/2022] Open
Abstract
Background Left ventricle rotation and torsion are fundamental components of myocardial function, and several software packages have been developed for analysis of these components. The purpose of this study was to compare the suitability of two software packages with different technical principles for analysis of rotation and torsion of the left ventricle during systole. Methods A group of hypertrophic cardiomyopathy (HCM) patients (N = 14, age 43 ± 11 years), mutation carriers without hypertrophy (N = 10, age 34 ± 13 years), and healthy relatives (N = 12, age 43 ± 17 years) underwent a cardiovascular magnetic resonance examination, including spatial modulation of magnetization tagging sequences in basal and apical planes of the left ventricle. The tagging images were analyzed offline using a harmonic phase image analysis method with Gabor filtering and a non-rigid registration-based free-form deformation technique. Left-ventricle rotation and torsion scores were obtained from end-diastole to end-systole with both software. Results Analysis was successful in all cases with both software applications. End-systolic torsion values between the study groups were not statistically different with either software. End-systolic apical rotation, end-systolic basal rotation, and end-systolic torsion were consistently higher when analyzed with non-rigid registration than with harmonic phase-based analysis (p < 0.0001). End-systolic rotation and torsion values had significant correlations between the two software (p < 0.0001), most significant in the apical plane. Conclusions When comparing absolute values of rotation and torsion between different individuals, software-specific reference values are required. Harmonic phase flow with Gabor filtering and non-rigid registration-based methods can both be used reliably in the analysis of systolic rotation and torsion patterns of the left ventricle.
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Affiliation(s)
- Lauri Lehmonen
- HUS Medical Imaging Center, Radiology, University of Helsinki and Helsinki University Hospital, PO Box 340, FI-00029, Helsinki, HUS, Finland. .,Department of Physics, University of Helsinki, Helsinki, Finland.
| | - Mikko Jalanko
- Department of Cardiology, Heart and Lung Center, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Mika Tarkiainen
- Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland
| | - Touko Kaasalainen
- HUS Medical Imaging Center, Radiology, University of Helsinki and Helsinki University Hospital, PO Box 340, FI-00029, Helsinki, HUS, Finland
| | - Johanna Kuusisto
- Institute of Clinical Medicine, Internal Medicine and Kuopio University Hospital, Kuopio, Finland
| | - Kirsi Lauerma
- HUS Medical Imaging Center, Radiology, University of Helsinki and Helsinki University Hospital, PO Box 340, FI-00029, Helsinki, HUS, Finland
| | - Sauli Savolainen
- HUS Medical Imaging Center, Radiology, University of Helsinki and Helsinki University Hospital, PO Box 340, FI-00029, Helsinki, HUS, Finland.,Department of Physics, University of Helsinki, Helsinki, Finland
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10
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Adalsteinsdottir B, Burke M, Maron BJ, Danielsen R, Lopez B, Diez J, Jarolim P, Seidman J, Seidman CE, Ho CY, Gunnarsson GT. Hypertrophic cardiomyopathy in myosin-binding protein C ( MYBPC3) Icelandic founder mutation carriers. Open Heart 2020; 7:e001220. [PMID: 32341788 PMCID: PMC7174027 DOI: 10.1136/openhrt-2019-001220] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 02/06/2020] [Accepted: 02/12/2020] [Indexed: 01/21/2023] Open
Abstract
Objective The myosin-binding protein C (MYBPC3) c.927-2A>G founder mutation accounts for >90% of sarcomeric hypertrophic cardiomyopathy (HCM) in Iceland. This cross-sectional observational study explored the penetrance and phenotypic burden among carriers of this single, prevalent founder mutation. Methods We studied 60 probands with HCM caused by MYBPC3 c.927-2A>G and 225 first-degree relatives. All participants underwent comprehensive clinical evaluation and relatives were genotyped. Results Genetic and clinical evaluation of relatives identified 49 genotype-positive (G+) relatives with left ventricular hypertrophy (G+/LVH+), 59 G+without LVH (G+/LVH-) and 117 genotype-negative relatives (unaffected). Compared with HCM probands, G+/LVH+ relatives were older at HCM diagnosis, had less LVH, a less prevalent diastolic dysfunction, fewer ECG abnormalities, lower serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin I levels, and fewer symptoms. The penetrance of HCM was influenced by age and sex; specifically, LVH was present in 39% of G+males but only 9% of G+females under age 40 years (p=0.015), versus 86% and 83%, respectively, after age 60 (p=0.89). G+/LVH- subjects had normal wall thicknesses, diastolic function and NT-proBNP levels, but subtle changes in LV geometry and more ECG abnormalities than their unaffected relatives. Conclusions Phenotypic expression of the Icelandic MYBPC3 founder mutation varies by age, sex and proband status. Men are more likely to have LVH at a younger age, and disease manifestations were more prominent in probands than in relatives identified via family screening. G+/LVH- individuals had subtle clinical differences from unaffected relatives well into adulthood, indicating subclinical phenotypic expression of the pathogenic mutation.
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Affiliation(s)
- Berglind Adalsteinsdottir
- Department of Medicine, University of Iceland, Reykjavik, Iceland.,Division of Cardiology, Landspitali - The National University Hospital of Iceland, Reykjavik, Iceland
| | - Michael Burke
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA.,Cardiology Division, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Barry J Maron
- Hypertrophic Cardiomyopathy Center, Division of Cardiology, Tufts Medical Center, Boston, Massachusetts, USA
| | - Ragnar Danielsen
- Division of Cardiology, Landspitali - The National University Hospital of Iceland, Reykjavik, Iceland
| | - Begoña Lopez
- Program of Cardiovascular Diseases, Centre for Applied Medical Research, University of Navarra, Pamplona, Navarra, Spain.,Carlos III Health Institute, Madrid, Spain
| | - Javier Diez
- Program of Cardiovascular Diseases, Centre for Applied Medical Research, University of Navarra, Pamplona, Navarra, Spain.,Carlos III Health Institute, Madrid, Spain
| | - Petr Jarolim
- Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Jonathan Seidman
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Christine E Seidman
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA.,Cardiovascular Division, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Howard Hughes Medical Institute, Boston, Massachusetts, USA
| | - Carolyn Y Ho
- Cardiovascular Division, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Gunnar Th Gunnarsson
- Department of Medicine, University of Iceland, Reykjavik, Iceland.,Department of Medicine, Akureyri Hospital, Akureyri, Iceland
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11
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Tran Vu MT, Nguyen TV, Huynh NV, Nguyen Thai HT, Pham Nguyen V, Ho Huynh TD. Presence of Hypertrophic Cardiomyopathy Related Gene Mutations and Clinical Manifestations in Vietnamese Patients With Hypertrophic Cardiomyopathy. Circ J 2019; 83:1908-1916. [PMID: 31308319 DOI: 10.1253/circj.cj-19-0190] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Hypertrophic cardiomyopathy (HCM) is associated primarily with pathogenic mutations in sarcomeric genes. The aim of this study was to identify the prevalence and distribution of disease-causing mutations in HCM-associated genes and the genotype-phenotype relationship in Vietnamese patients with HCM.Methods and Results:Genetic testing was performed by next-generation sequencing in 104 unrelated probands for 23 HCM-related genes and in 57 family members for the mutation(s) detected. Clinical manifestations were recorded for genotype-phenotype correlation analysis. Mutation detection rate was 43.4%. Mutations inMYBPC3accounted for 38.6%, followed byTPM1(20.5%),MYH7(18.2%),TNNT2(9.1%),TNNI3(4.5%) andMYL2(2.3%). A mutation inGLAassociated with Fabry disease was found in 1 patient. A mutation inTPM1(c.842T>C, p.Met281Thr) was identified in 8 unrelated probands (18.2%) and 8 family members from 5 probands. Genotype-positive status related toMYH7,TPM1, andTNNT2mutations was associated with severe clinical manifestations.MYH7-positive patients displayed worse prognosis compared withMYBPC3-positive patients. Interestingly,TPM1c.842T>C mutation was associated with high penetrance and severe HCM phenotype. CONCLUSIONS We report for the first time the prevalence of HCM-related gene variants in Vietnamese patients with HCM.MYH7,TPM1, andTNNT2mutations were associated with unfavorable prognosis.
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Affiliation(s)
| | - Thuy Vy Nguyen
- Research Center for Genetics and Reproductive Health, School of Medicine, Viet Nam National University.,Department of Genetics, Faculty of Biology and Biotechnology, University of Science, VNUHCM
| | | | - Hoang Tam Nguyen Thai
- Department of Genetics, Faculty of Biology and Biotechnology, University of Science, VNUHCM
| | | | - Thuy Duong Ho Huynh
- Research Center for Genetics and Reproductive Health, School of Medicine, Viet Nam National University.,Department of Genetics, Faculty of Biology and Biotechnology, University of Science, VNUHCM.,KTEST Science Company
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12
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Junttila MJ, Holmström L, Pylkäs K, Mantere T, Kaikkonen K, Porvari K, Kortelainen ML, Pakanen L, Kerkelä R, Myerburg RJ, Huikuri HV. Primary Myocardial Fibrosis as an Alternative Phenotype Pathway of Inherited Cardiac Structural Disorders. Circulation 2019; 137:2716-2726. [PMID: 29915098 DOI: 10.1161/circulationaha.117.032175] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 02/15/2018] [Indexed: 11/16/2022]
Abstract
BACKGROUND Myocardial fibrosis is a common postmortem finding among young individuals with sudden cardiac death. Because there is no known single cause, we tested the hypothesis that some cases of myocardial fibrosis in the absence of identifiable causes (primary myocardial fibrosis [PMF]) are associated with genetic variants. METHODS Tissue was obtained at autopsy from 4031 consecutive individuals with sudden cardiac death in Northern Finland, among whom PMF was the only structural finding in 145 subjects with sudden cardiac death. We performed targeted next-generation sequencing using a panel of 174 genes associated with myocardial structure and ion channel function when autopsies did not identify a secondary basis for myocardial fibrosis. All variants with an effect on protein and with a minor allele frequency <0.01 were classified as pathogenic or variants of uncertain significance on the basis of American College of Medical Genetics consensus guidelines. RESULTS Among the 96 specimens with DNA passing quality control (66%), postmortem genetic tests identified 24 variants of known or uncertain significance in 26 subjects (27%). Ten were pathogenic/likely pathogenic variants in 10 subjects (10%), and 14 were variants of uncertain significance in 11 genes among 16 subjects (17%). Five variants were in genes associated with arrhythmogenic right ventricular cardiomyopathy, 6 in hypertrophic cardiomyopathy-associated genes, and 11 in dilated cardiomyopathy-associated genes; 2 were not associated with these disorders. Four unique variants of uncertain significance cosegregated among multiple unrelated subjects with PMF. No pathogenic/likely pathogenic variants were detected in ion channel-encoding genes. CONCLUSIONS A large proportion of subjects with PMF at autopsy had variants in genes associated with arrhythmogenic right ventricular cardiomyopathy, dilated cardiomyopathy, and hypertrophic cardiomyopathy without autopsy findings of those diseases, suggesting that PMF can be an alternative phenotypic expression of structural disease-associated genetic variants or that risk-associated fibrosis was expressing before the primary disease. These findings have clinical implications for postmortem genetic testing and family risk profiling.
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Affiliation(s)
- M Juhani Junttila
- Research Unit of Internal Medicine, University of Oulu and University Hospital of Oulu, Finland (M.J.J., L.H., K.K., H.V.H.)
| | - Lauri Holmström
- Research Unit of Internal Medicine, University of Oulu and University Hospital of Oulu, Finland (M.J.J., L.H., K.K., H.V.H.)
| | - Katri Pylkäs
- Laboratory of Cancer Genetics and Tumor Biology, Cancer and Translational Medicine Research Unit and Biocenter Oulu (K. Pylkäs, T.M.)
| | - Tuomo Mantere
- Laboratory of Cancer Genetics and Tumor Biology, Cancer and Translational Medicine Research Unit and Biocenter Oulu (K. Pylkäs, T.M.)
| | - Kari Kaikkonen
- Research Unit of Internal Medicine, University of Oulu and University Hospital of Oulu, Finland (M.J.J., L.H., K.K., H.V.H.)
| | - Katja Porvari
- Department of Forensic Medicine, Research Unit of Internal Medicine, Medical Research Center Oulu (K, Porvari, M.-L.K., L.P.)
| | - Marja-Leena Kortelainen
- Department of Forensic Medicine, Research Unit of Internal Medicine, Medical Research Center Oulu (K, Porvari, M.-L.K., L.P.)
| | - Lasse Pakanen
- Department of Forensic Medicine, Research Unit of Internal Medicine, Medical Research Center Oulu (K, Porvari, M.-L.K., L.P.).,National Institute for Health and Welfare, Forensic Medicine Unit, Oulu, Finland (L.P.)
| | - Risto Kerkelä
- Research Unit of Biomedicine (R.K.), University of Oulu, Finland
| | - Robert J Myerburg
- Division of Cardiology, University of Miami Miller School of Medicine, FL (R.J.M.)
| | - Heikki V Huikuri
- Research Unit of Internal Medicine, University of Oulu and University Hospital of Oulu, Finland (M.J.J., L.H., K.K., H.V.H.)
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13
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Yotti R, Seidman CE, Seidman JG. Advances in the Genetic Basis and Pathogenesis of Sarcomere Cardiomyopathies. Annu Rev Genomics Hum Genet 2019; 20:129-153. [PMID: 30978303 DOI: 10.1146/annurev-genom-083118-015306] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) are common heart muscle disorders that are caused by pathogenic variants in sarcomere protein genes. HCM is characterized by unexplained cardiac hypertrophy (increased chamber wall thickness) that is accompanied by enhanced cardiac contractility and impaired relaxation. DCM is defined as increased ventricular chamber volume with contractile impairment. In this review, we discuss recent analyses that provide new insights into the molecular mechanisms that cause these conditions. HCM studies have uncovered the critical importance of conformational changes that occur during relaxation and enable energy conservation, which are frequently disturbed by HCM mutations. DCM studies have demonstrated the considerable prevalence of truncating variants in titin and have discerned that these variants reduce contractile function by impairing sarcomerogenesis. These new pathophysiologic mechanisms open exciting opportunities to identify new pharmacological targets and develop future cardioprotective strategies.
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Affiliation(s)
- Raquel Yotti
- Department of Cardiology, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón, 28007 Madrid, Spain; .,Centro de Investigación Biomédica en Red en Enfermedades Cardiovasculares (CIBERCV), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Christine E Seidman
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA; , .,Cardiovascular Division and Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.,Howard Hughes Medical Institute, Chevy Chase, Maryland 20815, USA
| | - Jonathan G Seidman
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA; ,
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14
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Tarkiainen M, Sipola P, Jalanko M, Heliö T, Jääskeläinen P, Kivelä K, Laine M, Lauerma K, Kuusisto J. CMR derived left ventricular septal convexity in carriers of the hypertrophic cardiomyopathy-causing MYBPC3-Q1061X mutation. Sci Rep 2019; 9:5960. [PMID: 30976029 PMCID: PMC6459818 DOI: 10.1038/s41598-019-42376-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 03/25/2019] [Indexed: 11/09/2022] Open
Abstract
This manuscript has not been published before and is not currently being considered for publication elsewhere. Increased septal convexity of left ventricle has been described in subjects with hypertrophic cardiomyopathy (HCM) -causing mutations without left ventricular hypertrophy (LVH). Our objective was to study septal convexity by cardiac magnetic resonance (CMR) in subjects with the Finnish founder mutation Q1016X in the myosin-binding protein C gene (MYBPC3). Septal convexity was measured in end-diastolic 4-chamber CMR image in 67 study subjects (47 subjects with the MYBPC3-Q1061X mutation and 20 healthy relatives without the mutation). Septal convexity was significantly increased in subjects with the MYBPC3-Q1061X mutation and LVH (n = 32) compared to controls (11.4 ± 4.3 vs 2.7 ± 3.2 mm, P < 0.001). In mutation carriers without LVH, there was a trend for increased septal convexity compared to controls (4.9 ± 2.5 vs 2.7 ± 3.2 mm, P = 0.074). When indexed for BSA, septal convexity in mutation carriers without LVH was 2.8 ± 1.4 mm/m2 and 1.5 ± 1.6 mm/m2 in controls (P = 0.036). In all mutation carriers, septal convexity correlated significantly with body surface area, age, maximal LV wall thickness, LV mass, and late gadolinium enhancement. Subjects with the MYBPC3–Q10961X mutation have increased septal convexity irrespective of the presence of LVH. Septal convexity appears to reflect septal remodeling, and could be useful in recognizing LVH negative mutation carriers.
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Affiliation(s)
- Mika Tarkiainen
- Department of Radiology, Kuopio University Hospital, Kuopio, Finland
| | - Petri Sipola
- Department of Radiology, Kuopio University Hospital, Kuopio, Finland
| | - Mikko Jalanko
- Heart and Lung Center, Department of Cardiology, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Tiina Heliö
- Heart and Lung Center, Department of Cardiology, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | | | - Kati Kivelä
- Department of Radiology, Kuopio University Hospital, Kuopio, Finland
| | - Mika Laine
- Heart and Lung Center, Department of Cardiology, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Kirsi Lauerma
- Department of Radiology, Helsinki University Central Hospital, Helsinki, Finland
| | - Johanna Kuusisto
- Centre for Medicine and Clinical Research, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland.
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15
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Jääskeläinen P, Vangipurapu J, Raivo J, Kuulasmaa T, Heliö T, Aalto-Setälä K, Kaartinen M, Ilveskoski E, Vanninen S, Hämäläinen L, Melin J, Kokkonen J, Nieminen MS, Laakso M, Kuusisto J. Genetic basis and outcome in a nationwide study of Finnish patients with hypertrophic cardiomyopathy. ESC Heart Fail 2019; 6:436-445. [PMID: 30775854 PMCID: PMC6437444 DOI: 10.1002/ehf2.12420] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 01/24/2019] [Indexed: 01/05/2023] Open
Abstract
AIMS Nationwide large-scale genetic and outcome studies in cohorts with hypertrophic cardiomyopathy (HCM) have not been previously published. METHODS AND RESULTS We sequenced 59 cardiomyopathy-associated genes in 382 unrelated Finnish patients with HCM and found 24 pathogenic or likely pathogenic mutations in six genes in 38.2% of patients. Most mutations were located in sarcomere genes (MYBPC3, MYH7, TPM1, and MYL2). Previously reported mutations by our study group (MYBPC3-Gln1061Ter, MYH7-Arg1053Gln, and TPM1-Asp175Asn) and a fourth major mutation MYH7-Val606Met accounted for 28.0% of cases. Mutations in GLA and PRKAG2 were found in three patients. Furthermore, we found 49 variants of unknown significance in 31 genes in 20.4% of cases. During a 6.7 ± 4.2 year follow-up, annual all-cause mortality in 482 index patients and their relatives with HCM was higher than that in the matched Finnish population (1.70 vs. 0.87%; P < 0.001). Sudden cardiac deaths were rare (n = 8). Systolic heart failure (hazard ratio 17.256, 95% confidence interval 3.266-91.170, P = 0.001) and maximal left ventricular wall thickness (hazard ratio 1.223, 95% confidence interval 1.098-1.363, P < 0.001) were independent predictors of HCM-related mortality and life-threatening cardiac events. The patients with a pathogenic or likely pathogenic mutation underwent an implantable cardioverter defibrillator implantation more often than patients without a pathogenic or likely pathogenic mutation (12.9 vs. 3.5%, P < 0.001), but there was no difference in all-cause or HCM-related mortality between the two groups. Mortality due to HCM during 10 year follow-up among the 5.2 million population of Finland was studied from death certificates of the National Registry, showing 269 HCM-related deaths, of which 32% were sudden. CONCLUSIONS We identified pathogenic and likely pathogenic mutations in 38% of Finnish patients with HCM. Four major sarcomere mutations accounted for 28% of HCM cases, whereas HCM-related mutations in non-sarcomeric genes were rare. Mortality in patients with HCM exceeded that of the general population. Finally, among 5.2 million Finns, there were at least 27 HCM-related deaths annually.
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Affiliation(s)
- Pertti Jääskeläinen
- Heart Center, Kuopio University Hospital, Kuopio, Finland.,Department of Medicine, Center for Medicine and Clinical Research, University of Eastern Finland, Kuopio University Hospital, P.O. Box 100, FIN-70029 KYS, Kuopio, Finland
| | - Jagadish Vangipurapu
- Faculty of Health Sciences, Institute of Clinical Medicine, Internal Medicine, University of Eastern Finland, Kuopio, Finland
| | - Joose Raivo
- Faculty of Health Sciences, Institute of Clinical Medicine, Internal Medicine, University of Eastern Finland, Kuopio, Finland
| | - Teemu Kuulasmaa
- Faculty of Health Sciences, Institute of Clinical Medicine, Internal Medicine, University of Eastern Finland, Kuopio, Finland
| | - Tiina Heliö
- Helsinki University Central Hospital, Helsinki, Finland
| | - Katriina Aalto-Setälä
- Heart Center Co., Institute of Biomedical Technology, Tampere University Hospital, University of Tampere, Tampere, Finland
| | | | | | - Sari Vanninen
- Heart Center Co., Tampere University Hospital, Tampere, Finland
| | | | - John Melin
- Central Finland Central Hospital, Jyväskylä, Finland
| | | | | | | | - Markku Laakso
- Department of Medicine, Center for Medicine and Clinical Research, University of Eastern Finland, Kuopio University Hospital, P.O. Box 100, FIN-70029 KYS, Kuopio, Finland
| | - Johanna Kuusisto
- Department of Medicine, Center for Medicine and Clinical Research, University of Eastern Finland, Kuopio University Hospital, P.O. Box 100, FIN-70029 KYS, Kuopio, Finland
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16
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Jalanko M, Heliö T, Mustonen P, Kokkonen J, Huhtala H, Laine M, Jääskeläinen P, Tarkiainen M, Lauerma K, Sipola P, Laakso M, Kuusisto J, Nikus K. Novel electrocardiographic features in carriers of hypertrophic cardiomyopathy causing sarcomeric mutations. J Electrocardiol 2018; 51:983-989. [PMID: 30497761 DOI: 10.1016/j.jelectrocard.2018.07.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 07/04/2018] [Accepted: 07/14/2018] [Indexed: 10/28/2022]
Abstract
OBJECTIVES The sensitivity and specificity of the conventional 12-lead ECG to identify carriers of hypertrophic cardiomyopathy (HCM) - causing mutations without left ventricular hypertrophy (LVH) has been limited. We assessed the ability of novel electrocardiographic parameters to improve the detection of HCM mutation carriers. METHODS We studied 140 carriers (G+) of the TPM1-Asp175Asn or MYBPC3-Gln1061X pathogenic variants for HCM: The G+/LVH+ group (n = 98) consisted of mutation carriers with LVH and the G+/LVH- group (n = 42) without LVH. The control group consisted of 30 subjects. The standard 12-lead ECG was comprehensively analyzed and two novel ECG variables were introduced: RV1<RV2>RV3 and septal remodeling. A subset of 65 individuals underwent cardiac magnetic resonance imaging and 2D strain echocardiography. RESULTS Conventional major ECG criteria were sensitive (90%) and specific (97%) in identifying G+/LVH+ subjects. RV1<RV2>RV3 and septal remodeling were more prevalent in the G+/LVH- subjects compared to the control group (33% vs 3%, p = 0.005 and 45% vs 3%, p < 0.001, respectively). The combination of RV1<RV2>RV3 and Q waves and repolarization abnormalities (QR) differentiated between the G+/LVH- subjects and the control group with a sensitivity of 52% and specificity of 97%. The combination of septal remodeling and QR differentiated between G+/LVH- subjects and the control group with a sensitivity of 64% and specificity of 97%. CONCLUSIONS The novel ECG-parameters RV1<RV2>RV3 and septal remodeling were effective in identifying G+/LVH- subjects and could be useful in the diagnostics of new suspected HCM patients and in the screening and follow-up of HCM families.
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Affiliation(s)
- Mikko Jalanko
- Heart and Lung Center, Department of Cardiology, Helsinki University Hospital and University of Helsinki, Helsinki, Finland.
| | - Tiina Heliö
- Heart and Lung Center, Department of Cardiology, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | | | | | - Heini Huhtala
- Faculty of Social Sciences, University of Tampere, Finland
| | - Mika Laine
- Heart and Lung Center, Department of Cardiology, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | | | - Mika Tarkiainen
- Department of Radiology, Kuopio University Hospital, Kuopio, Finland
| | - Kirsi Lauerma
- Department of Radiology, Helsinki University Hospital, Helsinki, Finland
| | - Petri Sipola
- Department of Radiology, Kuopio University Hospital, Kuopio, Finland
| | - Markku Laakso
- Center for Medicine and Clinical Research, University of Eastern Finland and Department of Medicine, Kuopio University Hospital, Kuopio, Finland
| | - Johanna Kuusisto
- Center for Medicine and Clinical Research, University of Eastern Finland and Department of Medicine, Kuopio University Hospital, Kuopio, Finland
| | - Kjell Nikus
- Heart Center, Department of Cardiology, Tampere University Hospital, and Faculty of Medicine and Life Sciences, University of Tampere, Finland
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17
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Vanninen SUM, Leivo K, Seppälä EH, Aalto-Setälä K, Pitkänen O, Suursalmi P, Annala AP, Anttila I, Alastalo TP, Myllykangas S, Heliö TM, Koskenvuo JW. Heterozygous junctophilin-2 (JPH2) p.(Thr161Lys) is a monogenic cause for HCM with heart failure. PLoS One 2018; 13:e0203422. [PMID: 30235249 PMCID: PMC6147424 DOI: 10.1371/journal.pone.0203422] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Accepted: 08/21/2018] [Indexed: 12/27/2022] Open
Abstract
During the last two decades, mutations in sarcomere genes have found to comprise the most common cause for hypertrophic cardiomyopathy (HCM), but still significant number of patients with dominant HCM in the family are left without molecular genetic diagnosis. Next generation sequencing (NGS) does not only enable evaluation of established HCM genes but also candidate genes for cardiomyopathy are frequently tested which may lead to a situation where conclusive interpretation of the variant requires extensive family studies. We aimed to characterize the phenotype related to a variant in the junctophilin-2 (JPH2) gene, which is less known non-sarcomeric candidate gene. In addition, we did extensive review of the literature and databases about JPH2 variation in association with cardiac disease. We characterize nine Finnish index patients with HCM and heterozygous for JPH2 c.482C>A, p.(Thr161Lys) variant were included and segregation studies were performed. We identified 20 individuals affected with HCM with or without systolic heart failure and conduction abnormalities in the nine Finnish families with JPH2 p.(Thr161Lys) variant. We found 26 heterozygotes with the variant and penetrance was 71% by age 60 and 100% by age 80. Co-segregation of the variant with HCM phenotype was observed in six families. Main clinical features were left ventricular hypertrophy, arrhythmia vulnerability and conduction abnormalities including third degree AV-block. In some patients end-stage severe left ventricular heart failure with normal or mildly enlarged diastolic dimensions was detected. In conclusion, we propose that the heterozygous JPH2 p.(Thr161Lys) variant is a new Finnish mutation causing atypical HCM.
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Affiliation(s)
| | - Krista Leivo
- Heart and Lung Center, Helsinki University Hospital, University of Helsinki, Helsinki, Finland
| | | | - Katriina Aalto-Setälä
- Heart Center, Tampere University Hospital, Tampere, Finland
- Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland
| | - Olli Pitkänen
- Divisions of Pediatric Cardiology, Children's Hospital/Helsinki University Hospital, Helsinki, Finland
| | - Piia Suursalmi
- Department of Pediatrics, Tampere University Hospital, Tampere, Finland
| | - Antti-Pekka Annala
- Department of Internal Medicine, Seinäjoki Central Hospital, Seinäjoki, Finland
| | - Ismo Anttila
- Department of Internal Medicine, Seinäjoki Central Hospital, Seinäjoki, Finland
| | - Tero-Pekka Alastalo
- Blueprint Genetics, Helsinki, Finland
- Divisions of Pediatric Cardiology, Children's Hospital/Helsinki University Hospital, Helsinki, Finland
| | - Samuel Myllykangas
- Blueprint Genetics, Helsinki, Finland
- Institute of Biomedicine, University of Helsinki, Helsinki, Finland
| | - Tiina M. Heliö
- Heart and Lung Center, Helsinki University Hospital, University of Helsinki, Helsinki, Finland
| | - Juha W. Koskenvuo
- Blueprint Genetics, Helsinki, Finland
- Department of Clinical Physiology and Nuclear Medicine, HUS Medical Imaging Center, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
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18
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Prajapati C, Ojala M, Aalto-Setälä K. Divergent effects of adrenaline in human induced pluripotent stem cell-derived cardiomyocytes obtained from hypertrophic cardiomyopathy. Dis Model Mech 2018; 11:dmm.032896. [PMID: 29361520 PMCID: PMC5894949 DOI: 10.1242/dmm.032896] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 12/22/2017] [Indexed: 12/26/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a common inherited cardiac disease that affects the heart muscle with diverse clinical outcomes. HCM can cause sudden cardiac death (SCD) during or immediately after mild to rigorous physical activity in young patients. However, the mechanism causing SCD as a result of exercise remains unknown, but exercise-induced ventricular arrhythmias are thought to be responsible for this fatal consequence. To understand the disease mechanism behind HCM in a better way, we generated patient-specific induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) from HCM patients carrying either the MYBPC3-Gln1061X or TPM1-Asp175Asn mutation. We extensively investigated the effects of low to high concentrations of adrenaline on action potential characteristics, and the occurrence of arrhythmias in the presence of various concentrations of adrenaline and in wash-out condition. We classified and quantified different types of arrhythmias observed in hiPSC-CMs, and found that the occurrence of arrhythmias was dependent on concentrations of adrenaline and positions of mutations in genes causing HCM. In addition, we observed ventricular tachycardia types of arrhythmias in hiPSC-CMs carrying the TPM1-Asp175Asn mutation. We additionally examined the antiarrhythmic potency of bisoprolol in HCM-specific hiPSC-CMs. However, bisoprolol could not reduce the occurrence of arrhythmias during administration or during the wash-out condition of adrenaline in HCM-specific hiPSC-CMs. Our study demonstrates hiPSC-CMs as a promising tool for studying HCM. The experimental design used in this study could be suitable and beneficial for studying other components and drugs related to cardiac disease in general. Summary: Different concentrations of adrenaline have divergent effects during and immediately after administration in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) obtained from hypertrophic cardiomyopathy (HCM) patients. Bisoprolol could not reduce the arrhythmias in HCM-specific hiPSC-CMs.
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Affiliation(s)
| | - Marisa Ojala
- BioMediTech, University of Tampere, 33014 Tampere, Finland
| | - Katriina Aalto-Setälä
- BioMediTech, University of Tampere, 33014 Tampere, Finland .,Faculty of Medicine and Life Science, University of Tampere, 33014 Tampere, Finland.,Heart Hospital, Tampere University Hospital, 33521 Tampere, Finland
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19
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Ross SB, Bagnall RD, Ingles J, Van Tintelen JP, Semsarian C. Burden of Recurrent and Ancestral Mutations in Families With Hypertrophic Cardiomyopathy. ACTA ACUST UNITED AC 2017; 10:CIRCGENETICS.116.001671. [DOI: 10.1161/circgenetics.116.001671] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 02/16/2017] [Indexed: 02/06/2023]
Affiliation(s)
- Samantha Barratt Ross
- From the Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, Newtown, New South Wales, Australia (S.B.R., R.D.B., J.I., C.S.); Sydney Medical School, University of Sydney, New South Wales, Australia (S.B.R., R.D.B., J.I., C.S.); Department of Cardiology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia (J.I., C.S.); and Department of Clinical Genetics, Academic Medical Centre, University of Amsterdam, The Netherlands (J.P.V.T.)
| | - Richard D. Bagnall
- From the Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, Newtown, New South Wales, Australia (S.B.R., R.D.B., J.I., C.S.); Sydney Medical School, University of Sydney, New South Wales, Australia (S.B.R., R.D.B., J.I., C.S.); Department of Cardiology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia (J.I., C.S.); and Department of Clinical Genetics, Academic Medical Centre, University of Amsterdam, The Netherlands (J.P.V.T.)
| | - Jodie Ingles
- From the Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, Newtown, New South Wales, Australia (S.B.R., R.D.B., J.I., C.S.); Sydney Medical School, University of Sydney, New South Wales, Australia (S.B.R., R.D.B., J.I., C.S.); Department of Cardiology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia (J.I., C.S.); and Department of Clinical Genetics, Academic Medical Centre, University of Amsterdam, The Netherlands (J.P.V.T.)
| | - J. Peter Van Tintelen
- From the Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, Newtown, New South Wales, Australia (S.B.R., R.D.B., J.I., C.S.); Sydney Medical School, University of Sydney, New South Wales, Australia (S.B.R., R.D.B., J.I., C.S.); Department of Cardiology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia (J.I., C.S.); and Department of Clinical Genetics, Academic Medical Centre, University of Amsterdam, The Netherlands (J.P.V.T.)
| | - Christopher Semsarian
- From the Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, Newtown, New South Wales, Australia (S.B.R., R.D.B., J.I., C.S.); Sydney Medical School, University of Sydney, New South Wales, Australia (S.B.R., R.D.B., J.I., C.S.); Department of Cardiology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia (J.I., C.S.); and Department of Clinical Genetics, Academic Medical Centre, University of Amsterdam, The Netherlands (J.P.V.T.)
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20
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Nueva mutación fundadora en MYBPC3: comparación fenotípica con la mutación de MYBPC3 más frecuente en España. Rev Esp Cardiol 2017. [DOI: 10.1016/j.recesp.2016.06.025] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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21
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Kuusisto J, Sipola P, Jääskeläinen P, Naukkarinen A. Current perspectives in hypertrophic cardiomyopathy with the focus on patients in the Finnish population: a review. Ann Med 2016; 48:496-508. [PMID: 27460395 DOI: 10.1080/07853890.2016.1187764] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease, with the prevalence of about 1/500. During the last two decades, the knowledge of the etiology, pathogenesis, risk stratification and prevention of sudden death in HCM has substantially advanced. Most often, HCM is familial and caused by mutations in sarcomere genes, inherited in an autosomal dominant manner. In Finland, genetic background of HCM is unique, with a few founder mutations in cardiac sarcomere genes accounting for a considerable proportion of the disease. Pathogenic mechanisms induced by disease-causing mutations are still poorly understood, although alterations in intracellular calcium handling and inefficient generation of contractile force in myocytes are considered key features in triggering the hypertrophic response. Clinical features of the disease are highly variable from no symptoms to the spectrum of exertional dyspnea, angina, palpitations, syncope and sudden death. In the current patient care, implantable cardioverter defibrillators (ICDs) are successfully used to prevent sudden cardiac death in high risk subjects. Targeted genetic testing is recommended to confirm the diagnosis in patients with HCM and to identify family members with the disease. Future research is needed to elucidate key cellular mechanisms leading to HCM, which may allow specific prevention and treatment of the disease. Key messages Hypertrophic cardiomyopathy, most often caused by defects in sarcomere genes, is the most common inherited heart disease, and a common cause of sudden cardiac death (SCD) in athletes and young subjects. Cardiac imaging, ECG and genetic testing are pivotal in the diagnosis of the disease in patients and first-degree relatives. Implantable cardioverter defibrillators in patients with high risk for SCD and tailored pharmacotherapy are efficient tools in patient care, but so far, exact mechanisms leading to cardiac hypertrophy in HCM are only partially understood, and there is no curative treatment for the disease.
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Affiliation(s)
- Johanna Kuusisto
- a Department of Medicine, Centre for Medicine and Clinical Research , University of Eastern Finland and Kuopio University Hospital , Kuopio , Finland
| | - Petri Sipola
- b Department of Clinical Radiology, Diagnostic Imaging Centre , Kuopio University Hospital , Kuopio , Finland
| | | | - Anita Naukkarinen
- d Department of Pathology, Diagnostic Imaging Centre , Kuopio University Hospital , Kuopio , Finland
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22
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Sabater-Molina M, Saura D, García-Molina Sáez E, González-Carrillo J, Polo L, Pérez-Sánchez I, Olmo MDC, Oliva-Sandoval MJ, Barriales-Villa R, Carbonell P, Pascual-Figal D, Gimeno JR. A Novel Founder Mutation in MYBPC3: Phenotypic Comparison With the Most Prevalent MYBPC3 Mutation in Spain. ACTA ACUST UNITED AC 2016; 70:105-114. [PMID: 28029522 DOI: 10.1016/j.rec.2016.06.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 06/23/2016] [Indexed: 01/22/2023]
Abstract
INTRODUCTION AND OBJECTIVES Mutations in MYBPC3 are the cause of hypertrophic cardiomyopathy (HCM). Although most lead to a truncating protein, the severity of the phenotype differs. We describe the clinical phenotype of a novel MYBPC3 mutation, p.Pro108Alafs*9, present in 13 families from southern Spain and compare it with the most prevalent MYBPC3 mutation in this region (c.2308+1 G>A). METHODS We studied 107 relatives of 13 index cases diagnosed as HCM carriers of the p.Pro108Alafs*9 mutation. Pedigree analysis, clinical evaluation, and genotyping were performed. RESULTS A total of 54 carriers of p.Pro108Alafs*9 were identified, of whom 39 had HCM. There were 5 cases of sudden death in the 13 families. Disease penetrance was greater as age increased and HCM patients were more frequently male and developed disease earlier than female patients. The phenotype was similar in p.Pro108Alafs*9 and in c.2308+1 G>A, but differences were found in several risk factors and in survival. There was a trend toward a higher left ventricular mass in p.Pro108Alafs*9 vs c.2308+1G>A. Cardiac magnetic resonance revealed a similar extent and pattern of fibrosis. CONCLUSIONS The p.Pro108Alafs*9 mutation is associated with HCM, high penetrance, and disease onset in middle age.
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Affiliation(s)
- María Sabater-Molina
- Unidad de Cardiopatías Hereditarias, Hospital Universitario Virgen de la Arrixaca, El Palmar, Murcia, Spain.
| | - Daniel Saura
- Departamento de Cardiología, Hospital Universitario Virgen de la Arrixaca, El Palmar, Murcia, Spain
| | | | - Josefa González-Carrillo
- Departamento de Cardiología, Hospital Universitario Virgen de la Arrixaca, El Palmar, Murcia, Spain
| | - Luis Polo
- Departamento de Patología, Hospital Universitario Virgen de la Arrixaca, El Palmar, Murcia, Spain
| | - Inmaculada Pérez-Sánchez
- Unidad de Cardiopatías Hereditarias, Hospital Universitario Virgen de la Arrixaca, El Palmar, Murcia, Spain
| | - María Del Carmen Olmo
- Departamento de Cardiología, Hospital Universitario Virgen de la Arrixaca, El Palmar, Murcia, Spain
| | | | - Roberto Barriales-Villa
- Unidad de Cardiopatías Hereditarias, Complexo Hospitalario Universitario A Coruña, A Coruña, Spain
| | - Pablo Carbonell
- Centro de Bioquímica y Genética Clínica, Hospital Universitario Virgen de la Arrixaca, El Palmar, Murcia, Spain
| | - Domigo Pascual-Figal
- Departamento de Cardiología, Hospital Universitario Virgen de la Arrixaca, El Palmar, Murcia, Spain
| | - Juan R Gimeno
- Departamento de Cardiología, Hospital Universitario Virgen de la Arrixaca, El Palmar, Murcia, Spain
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23
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Jalanko M, Tarkiainen M, Sipola P, Jääskeläinen P, Lauerma K, Laine M, Nieminen MS, Laakso M, Heliö T, Kuusisto J. Left ventricular mechanical dispersion is associated with nonsustained ventricular tachycardia in hypertrophic cardiomyopathy. Ann Med 2016; 48:417-427. [PMID: 27249556 DOI: 10.1080/07853890.2016.1186826] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
OBJECTIVE We assessed the value of speckle tracking two-dimensional (2D) strain echocardiography (2DSE) measured mechanical dispersion (MD) with other imaging and electrocardiographic parameters in differentiating hypertrophic cardiomyopathy (HCM) patients with and without nonsustained ventricular tachycardia (NSVT) on 24-h ambulatory ECG monitoring. METHODS AND RESULTS We studied 31 patients with HCM caused by the Finnish founder mutation MYBPC3-Q1061X and 20 control subjects with comprehensive 2DSE echocardiography and cardiac magnetic resonance imaging (CMRI). The presence of NSVT was assessed from ambulatory 24-h ECG monitoring. NSVT episodes were recorded in 11 (35%) patients with HCM. MD was significantly higher in HCM patients with NSVT (93 ± 41 ms) compared to HCM patients without NSVT (50 ± 18 ms, p = 0.012) and control subjects (41 ± 16 ms, p < 0.001). MD was the only variable independently associated with the presence of NSVT (OR: 1.60, 95% CI: 1.05-2.45, p = 0.030). Assessed by ROC curves, MD performed best in differentiating between HCM patients with and without NSVT (AUC = 0.81). CONCLUSIONS Increased mechanical dispersion was associated with NSVT in HCM patients on 24-h ambulatory ECG monitoring. Key messages The prediction of sudden cardiac death in hypertrophic cardiomyopathy remains a challenge and novel imaging methods are required to identify individuals at risk of malignant ventricular arrhythmias. Mechanical dispersion by speckle tracking echocardiography is associated with NSVT on 24-h ambulatory ECG monitoring in patients with hypertrophic cardiomyopathy.
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Affiliation(s)
- Mikko Jalanko
- a Department of Cardiology , Helsinki University Hospital, Heart and Lung Center , Helsinki , Finland
| | - Mika Tarkiainen
- b Department of Clinical Radiology , Kuopio University Hospital , Kuopio , Finland
| | - Petri Sipola
- b Department of Clinical Radiology , Kuopio University Hospital , Kuopio , Finland
| | | | - Kirsi Lauerma
- d HUS Medical Imaging Center, Radiology , University of Helsinki and Helsinki University Hospital , Helsinki , Finland
| | - Mika Laine
- a Department of Cardiology , Helsinki University Hospital, Heart and Lung Center , Helsinki , Finland
| | - Markku S Nieminen
- a Department of Cardiology , Helsinki University Hospital, Heart and Lung Center , Helsinki , Finland
| | - Markku Laakso
- e Institute of Clinical Medicine, Internal Medicine and Kuopio University Hospital , Kuopio , Finland
| | - Tiina Heliö
- a Department of Cardiology , Helsinki University Hospital, Heart and Lung Center , Helsinki , Finland
| | - Johanna Kuusisto
- e Institute of Clinical Medicine, Internal Medicine and Kuopio University Hospital , Kuopio , Finland
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Tarkiainen M, Sipola P, Jalanko M, Heliö T, Laine M, Järvinen V, Häyrinen K, Lauerma K, Kuusisto J. Cardiovascular magnetic resonance of mitral valve length in hypertrophic cardiomyopathy. J Cardiovasc Magn Reson 2016; 18:33. [PMID: 27259862 PMCID: PMC4893285 DOI: 10.1186/s12968-016-0250-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 05/17/2016] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Previous data suggest that mitral valve leaflets are elongated in hypertrophic cardiomyopathy (HCM), and mitral valve leaflet elongation may constitute a primary phenotypic expression of HCM. Our objective was to measure the length of mitral valve leaflets by cardiovascular magnetic resonance (CMR) in subjects with HCM caused by a Finnish founder mutation in the myosin-binding protein C gene (MYBPC3-Q1061X), carriers of the same mutation without left ventricular hypertrophy, as well as in unselected consecutive patients with HCM, and respective controls. METHODS Anterior mitral valve leaflet (AML) and posterior mitral valve leaflet (PML) lengths were measured by CMR in 47 subjects with the Q1061X mutation in the gene encoding MYBPC3 and in 20 healthy relatives without the mutation. In addition, mitral valve leaflet lengths were measured by CMR in 80 consecutive non-genotyped patients with HCM in CMR and 71 age- and gender-matched healthy subjects. RESULTS Of the subjects with the MYBPC-Q1016X mutation, 32 had left ventricular hypertrophy (LVH, LV maximal wall thickness ≥ 13 mm in CMR) and 15 had no hypertrophy. PML was longer in patients with the MYBPC3-Q1061X mutation and LVH than in controls of the MYBPC group (12.8 ± 2.8 vs 10.6 ± 1.9 mm, P = 0.013), but the difference between the groups was not statistically significant when PML was indexed for BSA (P = 0.066), or when PML length was adjusted for BSA, age, gender, LV mass and ejection fraction (P = 0.195). There was no significant difference in the PML length in mutation carriers without LVH and controls (11.1 ± 3.4 vs 10.6 ± 1.9, P = 0.52). We found no difference in AML lengths between the MYBPC mutation carriers with or without hypertrophy and controls. In 80 consecutive non-genotyped patients with HCM, there was no difference either in AML or PML lengths in subjects with HCM compared to respective control subjects. CONCLUSIONS In subjects with HCM caused by the Q1061X mutation in the MYBPC3 gene, the posterior mitral valve leaflets may be elongated, but mitral valve elongation does not constitute primary phenotypic expression of the disease. Instead, elongated mitral valve leaflets seem to be associated with body size and left ventricular remodeling.
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Affiliation(s)
- Mika Tarkiainen
- Department of Radiology, Kuopio University Hospital, Kuopio, Finland
| | - Petri Sipola
- Department of Radiology, Kuopio University Hospital, Kuopio, Finland
- University of Eastern Finland, Kuopio, Finland
| | - Mikko Jalanko
- Heart and Lung Center, Department of Cardiology, Helsinki University Central Hospital, Helsinki, Finland
| | - Tiina Heliö
- Heart and Lung Center, Department of Cardiology, Helsinki University Central Hospital, Helsinki, Finland
| | - Mika Laine
- Heart and Lung Center, Department of Cardiology, Helsinki University Central Hospital, Helsinki, Finland
| | - Vesa Järvinen
- HUS Medical Imaging Center, Clinical Physiology and Nuclear Medicine, Hyvinkää Hospital, Hyvinkää, Finland
| | | | - Kirsi Lauerma
- Department of Radiology, Helsinki University Central Hospital, Helsinki, Finland
| | - Johanna Kuusisto
- Centre for Medicine and Clinical Research, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland.
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25
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Kapplinger JD, Ackerman MJ. Founder Mutation Genotyping and Sudden Cardiac Arrest: The Promise of Precision Medicine Fulfilled or the Next Step Into Precise Uncertainty. CIRCULATION. CARDIOVASCULAR GENETICS 2016; 9:107-109. [PMID: 27094198 DOI: 10.1161/circgenetics.116.001387] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Affiliation(s)
- Jamie D Kapplinger
- From the Mayo Medical Scientist Training Program (J.D.K., M.J.A.); Departments of Cardiovascular Diseases, Pediatrics, and Molecular Pharmacology & Experimental Therapeutics; Divisions of Heart Rhythm Services and Pediatric Cardiology (M.J.A.); and Windland Smith Rice Sudden Death Genomics Laboratory (J.D.K., M.J.A.), Mayo Clinic, Rochester, MN
| | - Michael J Ackerman
- From the Mayo Medical Scientist Training Program (J.D.K., M.J.A.); Departments of Cardiovascular Diseases, Pediatrics, and Molecular Pharmacology & Experimental Therapeutics; Divisions of Heart Rhythm Services and Pediatric Cardiology (M.J.A.); and Windland Smith Rice Sudden Death Genomics Laboratory (J.D.K., M.J.A.), Mayo Clinic, Rochester, MN.
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Mutation-Specific Phenotypes in hiPSC-Derived Cardiomyocytes Carrying Either Myosin-Binding Protein C Or α-Tropomyosin Mutation for Hypertrophic Cardiomyopathy. Stem Cells Int 2015; 2016:1684792. [PMID: 27057166 PMCID: PMC4707351 DOI: 10.1155/2016/1684792] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 07/22/2015] [Accepted: 09/20/2015] [Indexed: 01/18/2023] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a genetic cardiac disease, which affects the structure of heart muscle tissue. The clinical symptoms include arrhythmias, progressive heart failure, and even sudden cardiac death but the mutation carrier can also be totally asymptomatic. To date, over 1400 mutations have been linked to HCM, mostly in genes encoding for sarcomeric proteins. However, the pathophysiological mechanisms of the disease are still largely unknown. Two founder mutations for HCM in Finland are located in myosin-binding protein C (MYBPC3-Gln1061X) and α-tropomyosin (TPM1-Asp175Asn) genes. We studied the properties of HCM cardiomyocytes (CMs) derived from patient-specific human induced pluripotent stem cells (hiPSCs) carrying either MYBPC3-Gln1061X or TPM1-Asp175Asn mutation. Both types of HCM-CMs displayed pathological phenotype of HCM but, more importantly, we found differences between CMs carrying either MYBPC3-Gln1061X or TPM1-Asp175Asn gene mutation in their cellular size, Ca(2+) handling, and electrophysiological properties, as well as their gene expression profiles. These findings suggest that even though the clinical phenotypes of the patients carrying either MYBPC3-Gln1061X or TPM1-Asp175Asn gene mutation are similar, the genetic background as well as the functional properties on the cellular level might be different, indicating that the pathophysiological mechanisms behind the two mutations would be divergent as well.
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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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Calore C, De Bortoli M, Romualdi C, Lorenzon A, Angelini A, Basso C, Thiene G, Iliceto S, Rampazzo A, Melacini P. A founder MYBPC3 mutation results in HCM with a high risk of sudden death after the fourth decade of life. J Med Genet 2015; 52:338-47. [PMID: 25740977 DOI: 10.1136/jmedgenet-2014-102923] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 02/10/2015] [Indexed: 11/03/2022]
Abstract
BACKGROUND Mutations in the cardiac myosin binding protein C (MYBPC3) gene account for a significant proportion of patients affected with hypertrophic cardiomyopathy (HCM). The aim of this study was to evaluate the penetrance and the impact of a frequent founder MYBPC3 mutation on HCM clinical expression and prognosis. METHODS AND RESULTS Mutation screening of MYBPC3 gene was performed in 97 HCM probands. Nineteen (19.5%) resulted to be carriers of the founder p.F305Pfs*27 mutation and other 45 mutation carriers were identified during the evaluation of 14 families. Eleven (38%) mutation carriers were diagnosed between ages 30 years and 40 years. Disease penetrance was incomplete (64.4%), age-related and was greater in men than women (85% vs 48%, p=0.009). Probands carrying the founder mutation exhibited highest prevalence of non-sustained ventricular tachycardia (63% vs 22%, p=0.003; 63% vs 23%, p=0.01) and implantable cardioverter-defibrillator (58% vs 17%, p=0.001; 58% vs 18%, p=0.005) when compared with probands without MYBPC3 mutations or carrying other MYBPC3 mutations. Reduced survival due to sudden cardiac death (SCD) or aborted SCD occurred more frequently after the fourth decade of life in probands carrying p.F305Pfs*27 mutation than those without MYBPC3 mutations (32% vs 15%, p=0.01). CONCLUSIONS p.F305Pfs*27 mutation carriers have a high probability to develop the disease between ages 30 years and 40 years with a significant major risk if they are men. This founder mutation is associated with an increase of SCD/aborted SCD events after the fourth decade of life.These findings are of relevant importance for management and clinical decision-making in patients with HCM.
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Affiliation(s)
- Chiara Calore
- Department of Cardiac, Thoracic, and Vascular Sciences, University of Padua, Padua, Italy
| | | | | | | | - Annalisa Angelini
- Department of Cardiac, Thoracic, and Vascular Sciences, University of Padua, Padua, Italy
| | - Cristina Basso
- Department of Cardiac, Thoracic, and Vascular Sciences, University of Padua, Padua, Italy
| | - Gaetano Thiene
- Department of Cardiac, Thoracic, and Vascular Sciences, University of Padua, Padua, Italy
| | - Sabino Iliceto
- Department of Cardiac, Thoracic, and Vascular Sciences, University of Padua, Padua, Italy
| | | | - Paola Melacini
- Department of Cardiac, Thoracic, and Vascular Sciences, University of Padua, Padua, Italy
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Sachs K, Andersen D, Sommer J, Winkelman A, Mehler PS. Avoiding medical complications during the refeeding of patients with anorexia nervosa. Eat Disord 2015; 23:411-21. [PMID: 25751129 DOI: 10.1080/10640266.2014.1000111] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Nutritional rehabilitation and weight restoration are key underpinnings of the treatment protocol for patients with anorexia nervosa. While their inherent state of malnutrition and weight loss is certainly not a healthy one, ironically, the very essence of the refeeding process, if done injudiciously, can also be unsafe for patients with anorexia nervosa. In this article we will provide a review of the major complications that may arise during refeeding, how best to avoid them, and how to treat them.
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Affiliation(s)
- Katherine Sachs
- a Department of Medicine , Denver Health Medical Center , Denver , Colorado , USA
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30
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Jääskeläinen P, Heliö T, Aalto-Setälä K, Kaartinen M, Ilveskoski E, Hämäläinen L, Melin J, Kärkkäinen S, Peuhkurinen K, Nieminen MS, Laakso M, Kuusisto J. A new common mutation in the cardiac beta-myosin heavy chain gene in Finnish patients with hypertrophic cardiomyopathy. Ann Med 2014; 46:424-9. [PMID: 24888384 DOI: 10.3109/07853890.2014.912834] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND In the nationwide FinHCM Study including 306 Finnish patients with hypertrophic cardiomyopathy (HCM), we have previously identified two founder mutations in the alpha-tropomyosin (TPM1-D175N) and myosin-binding protein C (MYBPC3-Q1061X) genes, accounting for 18% of all cases. Objective. To screen additional mutations, previously identified in eastern Finnish cohorts with HCM, in the FinHCM Study population. PATIENTS AND METHODS Ten mutations in the beta-myosin heavy chain gene (MYH7), TPM1, and MYBPC3 were screened. RESULTS MYH7-R1053Q was found in 17 of 306 patients (5.6%). No carriers of MYH7-R719W or N696S were found. A novel TPM1-D175G mutation was found in a single patient. MYBPC3 mutations were found in 14 patients: IVS5-2A-C in two, IVS14-13G-A in two, K811del in six, and A851insT in four patients. Altogether, a HCM-causing mutation was identified in 32 patients, accounting for 10.5% of all cases. In addition, two MYBPC3 variants R326Q and V896M with uncertain pathogenicity were found in eight and in 10 patients, respectively. CONCLUSION Combining the present findings with our previous results, a causative mutation was identified in 28% of the FinHCM cohort. MYH7-R1053Q was the third most common mutation, and should be screened in all new cases of HCM in Finland.
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Adalsteinsdottir B, Teekakirikul P, Maron BJ, Burke MA, Gudbjartsson DF, Holm H, Stefansson K, DePalma SR, Mazaika E, McDonough B, Danielsen R, Seidman JG, Seidman CE, Gunnarsson GT. Nationwide study on hypertrophic cardiomyopathy in Iceland: evidence of a MYBPC3 founder mutation. Circulation 2014; 130:1158-67. [PMID: 25078086 DOI: 10.1161/circulationaha.114.011207] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND The geographic isolation and homogeneous population of Iceland are ideally suited to ascertain clinical and genetic characteristics of hypertrophic cardiomyopathy (HCM) at the population level. METHODS AND RESULTS Medical records and cardiac imaging studies obtained between 1997 and 2010 were reviewed to identify Icelandic patients with HCM. Surviving patients were recruited for clinical and genetic studies. A previously identified Icelandic mutation, MYBPC3 c.927-2A>G, was genotyped, and mutation-negative samples were sequenced for HCM genes and other hypertrophic genes. Record review identified 180 patients with HCM. Genetic analyses of 151 patients defined pathogenic mutations in 101 (67%), including MYBPC3 c.927-2A>G (88 patients, 58%), 4 other MYBPC3 or MYH7 mutations (5 patients, 3.3%), and 2 GLA mutations (8 patients, 5.3%). Haplotype and genetic genealogical data defined MYBPC3 c.927-2A>G as a founder mutation, introduced into the Icelandic population in the 15th century, with a current population prevalence of 0.36%. MYBPC3 c.927-2A>G mutation carriers exhibited phenotypic diversity but were younger at diagnosis (42 versus 49 years; P=0.001) and sustained more adverse events (15% versus 2%; P=0.02) than mutation-negative patients. All-cause mortality for patients with HCM was similar to that of an age-matched Icelandic population (hazard ratio, 0.98; P=0.9). HCM-related mortality (0.78%/y) occurred at a mean age of 68 compared with 81 years for non-HCM-related mortality (P=0.02). CONCLUSIONS A founder MYBPC3 mutation that arose >550 years ago is the predominant cause of HCM in Iceland. The MYBPC3 c.927-2A>G mutation is associated with low adverse event rates but earlier cardiovascular mortality, illustrating the impact of genotype on outcomes in HCM.
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Affiliation(s)
- Berglind Adalsteinsdottir
- From Landspitali-The National University Hospital of Iceland, Reykjavik, Iceland (B.A., R.D.); Faculty of Medicine (B.A., K.S., G.T.G.) and School of Engineering and Natural Sciences (D.F.G.), University of Iceland, Reykjavik, Iceland; Department of Genetics, Harvard Medical School, Boston, MA (P.T., M.A.B., S.R.D., E.M., B.M., J.G.S., C.E.S.); Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation, Minneapolis, MN (B.J.M.); Cardiovascular Division, Brigham and Women's Hospital, Boston, MA (M.A.B., C.E.S.); deCODE Genetics, Reykjavik, Iceland (D.F.G., H.H., K.S.); Howard Hughes Medical Institute, Boston, MA (C.E.S.); and Akureyri Hospital, Akureyri, Iceland (G.T.G.).
| | - Polakit Teekakirikul
- From Landspitali-The National University Hospital of Iceland, Reykjavik, Iceland (B.A., R.D.); Faculty of Medicine (B.A., K.S., G.T.G.) and School of Engineering and Natural Sciences (D.F.G.), University of Iceland, Reykjavik, Iceland; Department of Genetics, Harvard Medical School, Boston, MA (P.T., M.A.B., S.R.D., E.M., B.M., J.G.S., C.E.S.); Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation, Minneapolis, MN (B.J.M.); Cardiovascular Division, Brigham and Women's Hospital, Boston, MA (M.A.B., C.E.S.); deCODE Genetics, Reykjavik, Iceland (D.F.G., H.H., K.S.); Howard Hughes Medical Institute, Boston, MA (C.E.S.); and Akureyri Hospital, Akureyri, Iceland (G.T.G.)
| | - Barry J Maron
- From Landspitali-The National University Hospital of Iceland, Reykjavik, Iceland (B.A., R.D.); Faculty of Medicine (B.A., K.S., G.T.G.) and School of Engineering and Natural Sciences (D.F.G.), University of Iceland, Reykjavik, Iceland; Department of Genetics, Harvard Medical School, Boston, MA (P.T., M.A.B., S.R.D., E.M., B.M., J.G.S., C.E.S.); Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation, Minneapolis, MN (B.J.M.); Cardiovascular Division, Brigham and Women's Hospital, Boston, MA (M.A.B., C.E.S.); deCODE Genetics, Reykjavik, Iceland (D.F.G., H.H., K.S.); Howard Hughes Medical Institute, Boston, MA (C.E.S.); and Akureyri Hospital, Akureyri, Iceland (G.T.G.)
| | - Michael A Burke
- From Landspitali-The National University Hospital of Iceland, Reykjavik, Iceland (B.A., R.D.); Faculty of Medicine (B.A., K.S., G.T.G.) and School of Engineering and Natural Sciences (D.F.G.), University of Iceland, Reykjavik, Iceland; Department of Genetics, Harvard Medical School, Boston, MA (P.T., M.A.B., S.R.D., E.M., B.M., J.G.S., C.E.S.); Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation, Minneapolis, MN (B.J.M.); Cardiovascular Division, Brigham and Women's Hospital, Boston, MA (M.A.B., C.E.S.); deCODE Genetics, Reykjavik, Iceland (D.F.G., H.H., K.S.); Howard Hughes Medical Institute, Boston, MA (C.E.S.); and Akureyri Hospital, Akureyri, Iceland (G.T.G.)
| | - Daniel F Gudbjartsson
- From Landspitali-The National University Hospital of Iceland, Reykjavik, Iceland (B.A., R.D.); Faculty of Medicine (B.A., K.S., G.T.G.) and School of Engineering and Natural Sciences (D.F.G.), University of Iceland, Reykjavik, Iceland; Department of Genetics, Harvard Medical School, Boston, MA (P.T., M.A.B., S.R.D., E.M., B.M., J.G.S., C.E.S.); Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation, Minneapolis, MN (B.J.M.); Cardiovascular Division, Brigham and Women's Hospital, Boston, MA (M.A.B., C.E.S.); deCODE Genetics, Reykjavik, Iceland (D.F.G., H.H., K.S.); Howard Hughes Medical Institute, Boston, MA (C.E.S.); and Akureyri Hospital, Akureyri, Iceland (G.T.G.)
| | - Hilma Holm
- From Landspitali-The National University Hospital of Iceland, Reykjavik, Iceland (B.A., R.D.); Faculty of Medicine (B.A., K.S., G.T.G.) and School of Engineering and Natural Sciences (D.F.G.), University of Iceland, Reykjavik, Iceland; Department of Genetics, Harvard Medical School, Boston, MA (P.T., M.A.B., S.R.D., E.M., B.M., J.G.S., C.E.S.); Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation, Minneapolis, MN (B.J.M.); Cardiovascular Division, Brigham and Women's Hospital, Boston, MA (M.A.B., C.E.S.); deCODE Genetics, Reykjavik, Iceland (D.F.G., H.H., K.S.); Howard Hughes Medical Institute, Boston, MA (C.E.S.); and Akureyri Hospital, Akureyri, Iceland (G.T.G.)
| | - Kari Stefansson
- From Landspitali-The National University Hospital of Iceland, Reykjavik, Iceland (B.A., R.D.); Faculty of Medicine (B.A., K.S., G.T.G.) and School of Engineering and Natural Sciences (D.F.G.), University of Iceland, Reykjavik, Iceland; Department of Genetics, Harvard Medical School, Boston, MA (P.T., M.A.B., S.R.D., E.M., B.M., J.G.S., C.E.S.); Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation, Minneapolis, MN (B.J.M.); Cardiovascular Division, Brigham and Women's Hospital, Boston, MA (M.A.B., C.E.S.); deCODE Genetics, Reykjavik, Iceland (D.F.G., H.H., K.S.); Howard Hughes Medical Institute, Boston, MA (C.E.S.); and Akureyri Hospital, Akureyri, Iceland (G.T.G.)
| | - Steven R DePalma
- From Landspitali-The National University Hospital of Iceland, Reykjavik, Iceland (B.A., R.D.); Faculty of Medicine (B.A., K.S., G.T.G.) and School of Engineering and Natural Sciences (D.F.G.), University of Iceland, Reykjavik, Iceland; Department of Genetics, Harvard Medical School, Boston, MA (P.T., M.A.B., S.R.D., E.M., B.M., J.G.S., C.E.S.); Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation, Minneapolis, MN (B.J.M.); Cardiovascular Division, Brigham and Women's Hospital, Boston, MA (M.A.B., C.E.S.); deCODE Genetics, Reykjavik, Iceland (D.F.G., H.H., K.S.); Howard Hughes Medical Institute, Boston, MA (C.E.S.); and Akureyri Hospital, Akureyri, Iceland (G.T.G.)
| | - Erica Mazaika
- From Landspitali-The National University Hospital of Iceland, Reykjavik, Iceland (B.A., R.D.); Faculty of Medicine (B.A., K.S., G.T.G.) and School of Engineering and Natural Sciences (D.F.G.), University of Iceland, Reykjavik, Iceland; Department of Genetics, Harvard Medical School, Boston, MA (P.T., M.A.B., S.R.D., E.M., B.M., J.G.S., C.E.S.); Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation, Minneapolis, MN (B.J.M.); Cardiovascular Division, Brigham and Women's Hospital, Boston, MA (M.A.B., C.E.S.); deCODE Genetics, Reykjavik, Iceland (D.F.G., H.H., K.S.); Howard Hughes Medical Institute, Boston, MA (C.E.S.); and Akureyri Hospital, Akureyri, Iceland (G.T.G.)
| | - Barbara McDonough
- From Landspitali-The National University Hospital of Iceland, Reykjavik, Iceland (B.A., R.D.); Faculty of Medicine (B.A., K.S., G.T.G.) and School of Engineering and Natural Sciences (D.F.G.), University of Iceland, Reykjavik, Iceland; Department of Genetics, Harvard Medical School, Boston, MA (P.T., M.A.B., S.R.D., E.M., B.M., J.G.S., C.E.S.); Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation, Minneapolis, MN (B.J.M.); Cardiovascular Division, Brigham and Women's Hospital, Boston, MA (M.A.B., C.E.S.); deCODE Genetics, Reykjavik, Iceland (D.F.G., H.H., K.S.); Howard Hughes Medical Institute, Boston, MA (C.E.S.); and Akureyri Hospital, Akureyri, Iceland (G.T.G.)
| | - Ragnar Danielsen
- From Landspitali-The National University Hospital of Iceland, Reykjavik, Iceland (B.A., R.D.); Faculty of Medicine (B.A., K.S., G.T.G.) and School of Engineering and Natural Sciences (D.F.G.), University of Iceland, Reykjavik, Iceland; Department of Genetics, Harvard Medical School, Boston, MA (P.T., M.A.B., S.R.D., E.M., B.M., J.G.S., C.E.S.); Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation, Minneapolis, MN (B.J.M.); Cardiovascular Division, Brigham and Women's Hospital, Boston, MA (M.A.B., C.E.S.); deCODE Genetics, Reykjavik, Iceland (D.F.G., H.H., K.S.); Howard Hughes Medical Institute, Boston, MA (C.E.S.); and Akureyri Hospital, Akureyri, Iceland (G.T.G.)
| | - Jonathan G Seidman
- From Landspitali-The National University Hospital of Iceland, Reykjavik, Iceland (B.A., R.D.); Faculty of Medicine (B.A., K.S., G.T.G.) and School of Engineering and Natural Sciences (D.F.G.), University of Iceland, Reykjavik, Iceland; Department of Genetics, Harvard Medical School, Boston, MA (P.T., M.A.B., S.R.D., E.M., B.M., J.G.S., C.E.S.); Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation, Minneapolis, MN (B.J.M.); Cardiovascular Division, Brigham and Women's Hospital, Boston, MA (M.A.B., C.E.S.); deCODE Genetics, Reykjavik, Iceland (D.F.G., H.H., K.S.); Howard Hughes Medical Institute, Boston, MA (C.E.S.); and Akureyri Hospital, Akureyri, Iceland (G.T.G.)
| | - Christine E Seidman
- From Landspitali-The National University Hospital of Iceland, Reykjavik, Iceland (B.A., R.D.); Faculty of Medicine (B.A., K.S., G.T.G.) and School of Engineering and Natural Sciences (D.F.G.), University of Iceland, Reykjavik, Iceland; Department of Genetics, Harvard Medical School, Boston, MA (P.T., M.A.B., S.R.D., E.M., B.M., J.G.S., C.E.S.); Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation, Minneapolis, MN (B.J.M.); Cardiovascular Division, Brigham and Women's Hospital, Boston, MA (M.A.B., C.E.S.); deCODE Genetics, Reykjavik, Iceland (D.F.G., H.H., K.S.); Howard Hughes Medical Institute, Boston, MA (C.E.S.); and Akureyri Hospital, Akureyri, Iceland (G.T.G.)
| | - Gunnar T Gunnarsson
- From Landspitali-The National University Hospital of Iceland, Reykjavik, Iceland (B.A., R.D.); Faculty of Medicine (B.A., K.S., G.T.G.) and School of Engineering and Natural Sciences (D.F.G.), University of Iceland, Reykjavik, Iceland; Department of Genetics, Harvard Medical School, Boston, MA (P.T., M.A.B., S.R.D., E.M., B.M., J.G.S., C.E.S.); Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation, Minneapolis, MN (B.J.M.); Cardiovascular Division, Brigham and Women's Hospital, Boston, MA (M.A.B., C.E.S.); deCODE Genetics, Reykjavik, Iceland (D.F.G., H.H., K.S.); Howard Hughes Medical Institute, Boston, MA (C.E.S.); and Akureyri Hospital, Akureyri, Iceland (G.T.G.)
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