Prognostic Implications of Pathogenic Truncating Variants in the TTN Gene

[Abstract] Introduction and objectives: TTN gene truncating variants (TTNtv) are a frequent cause of dilated cardiomyopathy (DCM). However, there are discrepant data on the associated prognosis. Our objectives were to describe the prevalence of TTNtv in our cohort and to compare the clinical course with that described in the literature. Methods: We included patients with DCM and genetic testing performed using next-generation sequencing. Through a systematic literature research, we collected information about carriers and affected relatives with TTNtv. We compared the cumulative percentage of affected carriers and the survival free of cardiovascular death. Results: One hundred and ten DCM patients were evaluated. A total of 13 TTNtv distributed in 14 probands were identified (12.7%). We found a 21.4% prevalence in familial cases. No significant differences in the relation between age and clinical disease expression were identified. Survival free of cardiovascular death curves constructed from data in the literature seems not to overestimate the risk in our population. Conclusions: The identification of TTNtv in patients with DCM is frequent and provides relevant information about the disease prognosis. The risk of cardiovascular death should not be underestimated. Age related penetrance need to be considered in the familial evaluation

Utilidad clínica del estudio genético en pacientes con miocardiopatía dilatada

[Abstract] Introduction and objectives: Dilated cardiomyopathy (DCM) is the most frequent cause of heart transplantation. The prevalence of familial disease can reach 50%. Our objective was to describe the genetic basis of DCM in a cohort with a high proportion of transplanted patients. Methods: We included patients with DCM and genetic testing performed using next-generation sequencing (NGS) that included at least 80 genes. Clinical data, family history and genetic results were retrospectively analysed. When possible, assessment of first-degree relatives was carried out. Results: Eighty-seven DCM patients and 308 relatives from 70 families were evaluated. Clinical prevalence of familial disease was 37% (32 patients). Forty-four percent of patients (38 patients) had required heart transplantation. A relevant variant was found in 43 patients (49%), 25 patients (29%) carried variants of unknown significance and in 19 patients (22%) the study was negative. Most genetic variants were found in sarcomeric genes and the yield of genetic testing was higher in patients with familial DCM. Conclusions: The yield of genetic testing in our DCM cohort was high, reaching 69% in familial cases. Mutational spectrum was heterogeneous and the identification of the specific aetiology of the disease often provided prognostic information.[Resumen] Introducción y objetivos. La miocardiopatía dilatada (MCD) es la causa más frecuente de trasplante cardiaco. Se considera que es familiar hasta en el 50% de los casos. Nuestro objetivo es describir los resultados genéticos obtenidos en una cohorte de pacientes con MCD, de los cuales una elevada proporción había acabado en trasplante cardiaco. Métodos. Se incluyeron pacientes con MCD a los que se realizó next-generation sequencing (NGS, «secuenciación de nueva generación») de al menos 80 genes relacionados con la enfermedad. Se analizaron retrospectivamente los datos clínicos de los pacientes, la historia familiar y los resultados del estudio genético. En los casos en los que fue posible, se realizó una evaluación de sus familiares de primer grado. Resultados. Fueron evaluados 87 pacientes con MCD y 308 familiares de 70 familias distintas. La prevalencia clínica de enfermedad familiar fue del 37% (32 pacientes) y el 44% (38 pacientes) habían precisado un trasplante cardiaco. En 43 pacientes (49%) se encontró al menos una variante relevante, en 25 pacientes (29%) se identificaron variantes de significado incierto y en 19 pacientes (22%) el estudio fue negativo. La mayoría de las mutaciones se encontraron en genes sarcoméricos y la rentabilidad del estudio fue mayor en los pacientes con MCD familiar. Conclusiones. El estudio genético NGS en nuestra población de pacientes con MCD tuvo una elevada rentabilidad, alcanzando el 69% en los casos familiares. El espectro mutacional fue heterogéneo y con frecuencia la identificación de la etiología específica de la enfermedad aportó información pronóstica

Late gadolinium enhancement distribution patterns in non-ischemic dilated cardiomyopathy: Genotype-phenotype correlation.

AIMS Late gadolinium enhancement (LGE) is frequently found in patients with dilated cardiomyopathy (DCM), there is little information about its frequency and distribution pattern according to underlying genetic substrate. We sought to describe LGE patterns according to genotype and to analyze the risk of major ventricular arrhythmias (MVA) according to patterns. METHODS AND RESULTS Cardiac magnetic resonance findings and LGE distribution according to genetics was performed in a cohort of 600 DCM patients followed at 20 Spanish centers. After exclusion of individuals with multiple causative gene variants or with variants in infrequent DCM-causing genes, 577 patients (34% females, mean age 53.5 years, LVEF 36.9 ± 13.9%) conformed the final cohort. A causative genetic variant was identified in 219 (38%) patients and 147 (25.5%) had LGE. Significant differences were found comparing LGE patterns between genes (P < 0.001). LGE was absent or rare in patients with variants in TNNT2, RBM20 and MYH7 (0%, 5% and 20%, respectively). Patients with variants in DMD, DSP and FLNC showed predominance of LGE subepicardial pattern (50%, 41% and 18%, respectively) whereas patients with variants in TTN, BAG3, LMNA and MYBPC3 showed unspecific LGE patterns. Genetic yield differed according to LGE pattern. Patients with subepicardial, lineal midwall, transmural, right ventricular insertion points or with combination of LGE patterns showed increased risk of MVA compared with patients without LGE. CONCLUSION LGE patterns in DCM has a specific distribution according to the affected gene. Certain LGE patterns are associated with increased risk of MVA and with increased yield of genetic testing.This study has been funded by Instituto Salud Carlos III (ISCIII) through the projects ‘PI18/0004, PI19/01283, and PI20/0320’ (co-funded by the European Regional Development Fund/European Social Fund ‘A way to make Europe’/‘Investing in your future’). The Hospital Universitario Puerta de Hierro, the Hospital Universitario Vall Hebrón, the Hospital General Universitario Gregorio Marañón, and the Hospital Universitario Virgen de la Arrixaca are members of the European Reference Network for Rare, Low Prevalence, and Complex Diseases of the Heart (ERN GUARD-Heart). F.d.F. receives grant support from ISCIII (CM20/00101). R.B. receives funding from the Obra Social la Caixa Foundation. M.B. receives funding from ISCIII (PI19/01283). The CNIC is supported by the ISCIII, Ministerio de Ciencia e Innovación of the Spanish Government (MCIN), and Pro CNIC Foundation.S

Mutations in TRIM63 cause an autosomal-recessive form of hypertrophic cardiomyopathy

Objective: Up to 50% of patients with hypertrophic cardiomyopathy (HCM) show no disease-causing variants in genetic studies. TRIM63 has been suggested as a candidate gene for the development of cardiomyopathies, although evidence for a causative role in HCM is limited. We sought to investigate the relationship between rare variants in TRIM63 and the development of HCM. Methods: TRIM63 was sequenced by next generation sequencing in 4867 index cases with a clinical diagnosis of HCM and in 3628 probands with other cardiomyopathies. Additionally, 3136 index cases with familial cardiovascular diseases other than cardiomyopathy (mainly channelopathies and aortic diseases) were used as controls. Results: Sixteen index cases with rare homozygous or compound heterozygous variants in TRIM63 (15 HCM and one restrictive cardiomyopathy) were included. No homozygous or compound heterozygous were identified in the control population. Familial evaluation showed that only homozygous and compound heterozygous had signs of disease, whereas all heterozygous family members were healthy. The mean age at diagnosis was 35 years (range 15-69). Fifty per cent of patients had concentric left ventricular hypertrophy (LVH) and 45% were asymptomatic at the moment of the first examination. Significant degrees of late gadolinium enhancement were detected in 80% of affected individuals, and 20% of patients had left ventricular (LV) systolic dysfunction. Fifty per cent had non-sustained ventricular tachycardia. Twenty per cent of patients suffered an adverse cerebrovascular event (20%). Conclusion: TRIM63 appears to be an uncommon cause of HCM inherited in an autosomal-recessive manner and associated with concentric LVH and a high rate of LV dysfunction

Predictores de riesgo en una cohorte española con cardiolaminopatías. Registro REDLAMINA

[Abstract] Introduction and objectives. According to sudden cardiac death guidelines, an implantable cardioverter-defibrillator (ICD) should be considered in patients with LMNA-related dilated cardiomyopathy (DCM) and ≥ 2 risk factors: male sex, left ventricular ejection fraction (LVEF) < 45%, nonsustained ventricular tachycardia (NSVT), and nonmissense genetic variants. In this study we aimed to describe the clinical characteristics of carriers of LMNA genetic variants among individuals from a Spanish cardiac-laminopathies cohort (REDLAMINA registry) and to assess previously reported risk criteria. Methods. The relationship between risk factors and cardiovascular events was evaluated in a cohort of 140 carriers (age ≥ 16 years) of pathogenic LMNA variants (54 probands, 86 relatives). We considered: a) major arrhythmic events (MAE) if there was appropriate ICD discharge or sudden cardiac death; b) heart failure death if there was heart transplant or death due to heart failure. Results. We identified 11 novel and 21 previously reported LMNA-related DCM variants. LVEF < 45% (P = .001) and NSVT (P < .001) were related to MAE, but not sex or type of genetic variant. The only factor independently related to heart failure death was LVEF < 45% (P < .001). Conclusions. In the REDLAMINA registry cohort, the only predictors independently associated with MAE were NSVT and LVEF < 45%. Therefore, female carriers of missense variants with either NSVT or LVEF < 45% should not be considered a low-risk group. It is important to individualize risk stratification in carriers of LMNA missense variants, because not all have the same prognosis.[Resumen] Introducción y objetivos. Según las guías de muerte súbita, se debe considerar un desfibrilador automático implantable (DAI) para los pacientes con miocardiopatía dilatada debida a variantes en el gen de la lamina (LMNA) con al menos 2 factores: varones, fracción de eyección del ventrículo izquierdo (FEVI) < 45%, taquicardia ventricular no sostenida (TVNS) y variantes no missense. Nuestro objetivo es describir las características clínicas de una cohorte española de pacientes con cardiolaminopatías (registro REDLAMINA) y evaluar los criterios de riesgo vigentes. Métodos. Se evaluó la relación entre factores de riesgo y eventos cardiovasculares en una cohorte de 140 portadores de variantes en LMNA (54 probandos, 86 familiares, edad ≥ 16 años). Se consideró: a) evento arrítmico mayor (EAM) si hubo descarga apropiada del DAI o muerte súbita, y b) muerte por insuficiencia cardiaca, incluidos los trasplantes. Resultados. Se identificaron 11 variantes nuevas y 21 previamente publicadas. La FEVI < 45% (p = 0,001) y la TVNS (p < 0,001) se relacionaron con los EAM, pero no el sexo o el tipo de variante (missense frente a no missense). La FEVI < 45% (p < 0,001) fue el único factor relacionado con la muerte por insuficiencia cardiaca. Conclusiones. En el registro REDLAMINA, los únicos 2 predictores asociados con EAM fueron la TVNS y la FEVI < 45%. No se debería considerar grupo de bajo riesgo a las portadoras de variantes missense con TVNS o FEVI < 45%. Es importante individualizar la estratificación del riesgo de los portadores de variantes missense en LMNA, porque no todas tienen el mismo pronóstico.This study received a grant from the Proyecto de investigación de la Sección de Insuficiencia Cardiaca 2017 from the Spanish Society of Cardiology and grants from the Instituto de Salud Carlos III (ISCIII) [PI14/0967, PI15/01551, AC16/0014] and ERA-CVD Joint Transnational Call 2016 (Genprovic). Grants from the ISCIII and the Ministerio de Economía y Competitividad de España (Spanish Department of Economy and Competitiveness) are supported by the Plan Estatal de I+D+i 2013-2016: Fondo Europeo de Desarrollo Regional (FEDER) “Una forma de hacer Europa”

Natural History of MYH7-Related Dilated Cardiomyopathy

BACKGROUND Variants in myosin heavy chain 7 (MYH7) are responsible for disease in 1% to 5% of patients with dilated cardiomyopathy (DCM); however, the clinical characteristics and natural history of MYH7-related DCM are poorly described. OBJECTIVES We sought to determine the phenotype and prognosis of MYH7-related DCM. We also evaluated the influence of variant location on phenotypic expression. METHODS We studied clinical data from 147 individuals with DCM-causing MYH7 variants (47.6% female; 35.6 +/- 19.2 years) recruited from 29 international centers. RESULTS At initial evaluation, 106 (72.1%) patients had DCM (left ventricular ejection fraction: 34.5% +/- 11.7%). Median follow-up was 4.5 years (IQR: 1.7-8.0 years), and 23.7% of carriers who were initially phenotype-negative developed DCM. Phenotypic expression by 40 and 60 years was 46% and 88%, respectively, with 18 patients (16%) first diagnosed at <18 years of age. Thirty-six percent of patients with DCM met imaging criteria for LV noncompaction. During follow-up, 28% showed left ventricular reverse remodeling. Incidence of adverse cardiac events among patients with DCM at 5 years was 11.6%, with 5 (4.6%) deaths caused by end-stage heart failure (ESHF) and 5 patients (4.6%) requiring heart transplantation. The major ventricular arrhythmia rate was low (1.0% and 2.1% at 5 years in patients with DCM and in those with LVEF of <= 35%, respectively). ESHF and major ventricular arrhythmia were significantly lower compared with LMNA-related DCM and similar to DCM caused by TTN truncating variants. CONCLUSIONS MYH7-related DCM is characterized by early age of onset, high phenotypic expression, low left ventricular reverse remodeling, and frequent progression to ESHF. Heart failure complications predominate over ventricular arrhythmias, which are rare. (C) 2022 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation

Enfermedad de Pompe

La enfermedad de Pompe forma parte de las enfermedades relacionadas con alteraciones en el depósito o el metabolismo del glucógeno. También conocida como deficiencia de maltasa ácida, enfermedad de depósito de glucógeno tipo IIA y deficiencia de alfa-glucosidasa ácida (GAA), fue la primera enfermedad del depósito de glucógeno descrita. Tiene una transmisión autosómica recesiva heredada, con más de 200 variantes patogénicas descritas hasta el momento. Su frecuencia de presentación es muy baja, y su manifestación, gravedad y fenotipo, así como el momento de inicio de los síntomas, dependen del grado de actividad residual de la GAA o de su completa ausencia. La forma más grave, denominada enfermedad de Pompe clásica de inicio infantil, se inicia antes de los 12 meses de edad y se presenta con cardiomiopatía hipertrófica rápidamente progresiva, obstrucción del tracto de salida del ventrículo izquierdo, hipotonía, debilidad muscular, dificultad respiratoria y pérdida progresiva de la independencia ventilatoria. Una forma menos grave, que generalmente se presenta después de los 12 meses de edad, denominada enfermedad de Pompe de inicio tardío, no suele presentar un compromiso cardiaco grave y sus síntomas principalmente están relacionados con el compromiso muscular proximal, que se manifiesta con debilidad muscular progresiva, pérdida de la autonomía para actividades musculares y finalmente compromiso de los músculos respiratorios. Por fortuna, se dispone de adecuados métodos para el diagnóstico y el seguimiento, y de una terapia de reemplazo enzimático que ha modificado de manera significativa el curso clínico de la enfermedad y su mortalidad.Q4Pompe disease is part of the diseases related to storage alterations or abnormal metabolism of glycogen. This disease, also known as, acid maltase deficiency, type IIA glycogen storage disease or acid α-glucosidase deficiency (GAA), was the first described glycogen storage disease, it has an inherited autosomal recessive transmission with more than 200 pathogenic variants described so far. Its frequency of presentation is very low and its presentation, severity and phenotype, as well as at the time of onset of symptoms depend on the degree of residual activity of GAA or its complete absence. The most severe form, called classic infantile onset Pompe disease, begins before 12 months of age, presents with rapidly progressive hypertrophic cardiomyopathy, left ventricular outflow tract obstruction, hypotonia, muscle weakness, respiratory distress and progressive loss of ventilatory independence. The less severe form, which generally presents after 12 months of age and is called late-onset Pompe disease, usually does not present a severe cardiac compromise and its symptoms are mainly related to proximal muscle compromise that manifests with progressive muscle weakness, loss of autonomy for muscular activities and finally compromise of the respiratory muscles. Fortunately, we have adequate methods for the diagnosis and follow-up, and enzyme replacement therapy that have significantly modified the clinical course of the disease and its mortality.Revista Nacional - Indexad

Potential Molecular Pathways Related to Pulmonary Artery Aneurysm Development: Lessons to Learn from the Aorta

Pulmonary arterial hypertension (PAH) is a rare disease caused by pulmonary vascular remodeling. Current vasodilator treatments have substantially improved patients' survival. This improved survival has led to the appearance of complications related to conditions previously underdiagnosed or even ignored, such as pulmonary artery aneurysm (PAA). The presence of a dilated pulmonary artery has been shown to be related to an increased risk of sudden cardiac death among PAH patients. This increased risk could be associated to the development of left main coronary artery compression or pulmonary artery dissection. Nevertheless, very little is currently known about the molecular mechanisms related to PAA. Thoracic aortic aneurysm (TAA) is a well-known condition with an increased risk of sudden death caused by acute aortic dissection. TAA may be secondary to chronic exposure to classic cardiovascular risk factors. In addition, a number of genetic variants have been shown to be related to a marked risk of TAA and dissection as part of multisystemic syndromes or isolated familial TAA. The molecular pathways implied in the development of TAA have been widely studied and described. Many of these molecular pathways are involved in the pathogenesis of PAH and could be involved in PAA. This review aims to describe all these common pathways to open new research lines that could help lead to a better understanding of the pathophysiology of PAH and PAA and their clinical implications.J.N. is a recipient of a predoctoral grant (Jordi Soler Soler) through CIBERCV. E.O. is a recipient of funds from Programa de Atracción de Talento (2017-T1/BMD-5185) of Comunidad de Madrid. P.E. is a recipient of a grant of the Spanish Ministry of Science and Universities for the study of molecular bases in pulmonary arterial hypertension (PI 18/01233). The CNIC is supported by the Instituto de Salud Carlos III (ISCIII), the Ministerio de Ciencia e Innovación, and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence (SEV-2015-0505).S

Abordaje de las cardiopatías familiares desde la Medicina genómica

Resumen: Las cardiopatías familiares son un grupo de enfermedades con alta heterogeneidad clínica y genética. Debido a que pueden heredarse y a su asociación con la muerte súbita, se recomienda efectuar un estudio clínico y genético del individuo afectado y su familia a través de una unidad especializada. Con la implementación de la secuenciación masiva se ha facilitado el acceso a los estudios genéticos en la práctica clínica de forma más rutinaria. Sin embargo, dada la gran cantidad de información obtenida se hacen necesarios el análisis y la interpretación adecuada de los resultados para garantizar un diagnóstico correcto. Este nuevo modelo de medicina amplía nuestra comprensión sobre estas patologías, gracias a que optimiza el diagnóstico, da una mejor aproximación pronóstica de los pacientes e identifica individuos asintomáticos en riesgo. Este artículo pretende realizar una revisión de la arquitectura genética de las enfermedades cardíacas hereditarias y proporcionar un enfoque práctico acerca de la utilidad de la Medicina genómica en el diagnóstico, la estratificación del riesgo y el estudio familiar en pacientes con este tipo de patologías. Abstract: The familial heart diseases are a group of diseases with high clinical and genomic heterogeneity. As they can be inherited and are associated with sudden death, it is recommended to perform a clinical and genetic study of the individual affected, as well as the family, in a specialised unit. The implementation of massive sequencing has meant that access to genetic studies is available in the most routine clinical practice. However, due to the large amount of information obtained, the results have to analysed and interpreted to ensure a correct diagnosis. This new medicine model widens the understanding of these diseases, as due to the diagnosis being optimised, it provides a more accurate prognosis for the patients, and identifies asymptomatic individuals at risk. A review is presented on the genetic architecture of heritable heart disease and provides a practical approach on the usefulness of Genomic Medicine in the diagnosis, risk stratification, and the familial study in patients with these types of heart diseases. Palabras clave: Miocardiopatías, Muerte súbita cardiaca, Asociación genotipo-fenotipo, Secuenciación masiva, Keywords: Cardiomyopathies, Sudden cardiac death, Genotype-phenotype association, Massive sequencin

Clinical heterogeneity of pulmonary arterial hypertension associated with variants in TBX4

Background The knowledge of hereditary predisposition has changed our understanding of Pulmonary Arterial Hypertension. Genetic testing has been widely extended and the application of Pulmonary Arterial Hypertension specific gene panels has allowed its inclusion in the diagnostic workup and increase the diagnostic ratio compared to the traditional sequencing techniques. This is particularly important in the differential diagnosis between Pulmonary Arterial Hypertension and Pulmonary Venoocclusive Disease. Methods Since November 2011, genetic testing is offered to all patients with idiopathic, hereditable and associated forms of Pulmonary Arterial Hypertension or Pulmonary Venoocclusive Disease included in the Spanish Registry of Pulmonary Arterial Hypertension. Herein, we present the clinical phenotype and prognosis of all Pulmonary Arterial Hypertension patients with disease-associated variants in TBX4. Results Out of 579 adults and 45 children, we found in eight patients from seven families, disease-causing associated variants in TBX4. All adult patients had a moderate-severe reduction in diffusion capacity. However, we observed a wide spectrum of clinical presentations, including Pulmonary Venoocclusive Disease suspicion, interstitial lung disease, pulmonary vascular abnormalities and congenital heart disease. Conclusions Genetic testing is now essential for a correct diagnosis work-up in Pulmonary Arterial Hypertension. TBX4-associated Pulmonary Arterial Hypertension has marked clinical heterogeneity. In this regard, a genetic study is extremely useful to obtain an accurate diagnosis and provide appropriate managementInstituto de Salud Carlos III | Ref. PI 18/0123