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1.
Clin Genet ; 105(2): 185-189, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37904629

RESUMO

Dilated cardiomyopathy (DCM) is a heart disease characterized by left ventricular dilatation and systolic dysfunction. In 30% of cases, pathogenic variants, essentially private to each patient, are identified in at least one of almost 50 reported genes. Thus, while costly, exons capture-based Next Generation Sequencing (NGS) of a targeted gene panel appears as the best strategy to genetically diagnose DCM. Here, we report a NGS strategy applied to pools of 8 DNAs from DCM patients and validate its robustness for rare variants detection at 4-fold reduced cost. Our pipeline uses Freebayes to detect variants with the expected 1/16 allele frequency. From the whole set of detected rare variants in 96 pools we set the variants quality parameters optimizing true positives calling. When compared to simplex DNA sequencing in a shared subset of 50 DNAs, 96% of SNVs/InsDel were accurately identified in pools. Extended to the 384 DNAs included in the study, we detected 100 variants (ACMG class 4 and 5), mostly in well-known morbid gene causing DCM such as TTN, MYH7, FLNC, and TNNT2. To conclude, we report an original pool-sequencing NGS method accurately detecting rare variants. This innovative approach is cost-effective for genetic diagnostic in rare diseases.


Assuntos
Cardiomiopatias , Cardiomiopatia Dilatada , Humanos , Cardiomiopatia Dilatada/diagnóstico , Cardiomiopatia Dilatada/genética , Análise Custo-Benefício , DNA/genética , Frequência do Gene
2.
Clin Genet ; 105(6): 676-682, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38356193

RESUMO

Biallelic disease-causing variants in the ALPK3 gene were first identified in children presenting with a severe cardiomyopathy. More recently, it was shown that carriers of heterozygous ALPK3 null variants are at risk of developing hypertrophic cardiomyopathy (HCM) with an adult onset. Since the number of reported ALPK3 patients is small, the mutational spectrum and clinical data are not fully described. In this multi-centric study, we described the molecular and clinical spectrum of a large cohort of ALPK3 patients. Genetic testing using targeted next generation sequencing was performed in 16 183 cardiomyopathy index cases. Thirty-six patients carried at least one null ALPK3 variant. The five paediatric patients carried two ALPK3 variants, all presented an HCM phenotype with severe outcomes (one transplantation, one heart failure and one cardiac arrest). The 31 adult patients carried heterozygous variants and the main phenotype was HCM (n = 26/31); including 15% (n = 4) presented with an apical or a concentric form of hypertrophy. Reporting a large cohort of ALPK3 patients, this collaborative work confirmed a strong association with HCM and suggesting his screening in the context of idiopathic HCM.


Assuntos
Cardiomiopatia Hipertrófica , Proteínas Musculares , Fenótipo , Proteínas Quinases , Humanos , Cardiomiopatia Hipertrófica/genética , Masculino , Feminino , Adulto , Criança , Adolescente , França/epidemiologia , Pessoa de Meia-Idade , Prevalência , Mutação , Pré-Escolar , Predisposição Genética para Doença , Estudos de Coortes , Heterozigoto , Adulto Jovem , Testes Genéticos , Lactente , Estudos de Associação Genética , Sequenciamento de Nucleotídeos em Larga Escala , Idoso
3.
Clin Genet ; 104(1): 63-72, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37209000

RESUMO

Cardiomyopathies are diseases of the heart muscle with variable clinical expressivity. Most of forms are inherited as dominant trait, and with incomplete penetrance until adulthood. Severe forms of cardiomyopathies were observed during the antenatal period with a pejorative issue leading to fetal death or medical interruption of pregnancy. Variable phenotypes and genetic heterogeneity make etiologic diagnosis difficult. We report 11 families (16 cases) whose unborn, newborn or infant with early onset cardiomyopathies. Detailed morphological and histological examinations of hearts were implemented, as well as genetic analysis on a cardiac targeted NGS panel. This strategy allowed the identification of the genetic cause of the cardiomyopathy in 8/11 families. Compound heterozygous mutations in dominant adulthood cardiomyopathy genes were found in two, pathogenic variants in co-dominant genes in one, de novo mutations in 5 including a germline mosaicism in one family. Parental testing was systematically performed to detect mutation carriers, and to manage cardiological surveillance and propose a genetic counseling. This study highlights the great diagnostic value of the genetic testing of severe antenatal cardiomyopathy both for genetic counseling and to detect presymptomatic parents at higher risk of developing cardiomyopathy.


Assuntos
Cardiomiopatias , Gravidez , Humanos , Feminino , Cardiomiopatias/diagnóstico , Testes Genéticos , Mutação , Fenótipo , Aconselhamento Genético
4.
Neth Heart J ; 31(7-8): 300-307, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37488328

RESUMO

INTRODUCTION: The MYH7 c.5135G > A p.(Arg1712Gln) variant has been identified in several patients worldwide and is classified as pathogenic in the ClinVar database. We aimed to delineate its associated phenotype and evaluate a potential founder effect. METHODS: We retrospectively collected clinical and genetic data of 22 probands and 74 family members from an international cohort. RESULTS: In total, 53 individuals carried the MYH7 p.(Arg1712Gln) variant, of whom 38 (72%) were diagnosed with hypertrophic cardiomyopathy (HCM). Mean age at HCM diagnosis was 48.8 years (standard deviation: 18.1; range: 8-74). The clinical presentation ranged from asymptomatic HCM to arrhythmias (atrial fibrillation and malignant ventricular arrhythmias). Aborted sudden cardiac death (SCD) leading to the diagnosis of HCM occurred in one proband at the age of 68 years, and a family history of SCD was reported by 39% (5/13) probands. Neither heart failure deaths nor heart transplants were reported. Women had a generally later-onset disease, with 14% of female carriers diagnosed with HCM at age 50 years compared with 54% of male carriers. In both sexes, the disease was fully penetrant by age 75 years. Haplotypes were reconstructed for 35 patients and showed a founder effect in a subset of patients. CONCLUSION: MYH7 p.(Arg1712Gln) is a pathogenic founder variant with a consistent HCM phenotype that may present with delayed penetrance. This suggested that clinical follow-up should be pursued after the seventh decade in healthy carriers and that longer intervals between screening may be justified in healthy women < 30 years.

5.
J Card Fail ; 27(6): 677-681, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34088380

RESUMO

BACKGROUND: Few data exist concerning genotype-phenotype relationships in left ventricular noncompaction (LVNC). METHODS AND RESULTS: From a multicenter French Registry, we report the genetic and clinical spectrum of 95 patients with LVNC, and their genotype-phenotype relationship. Among the 95 LVNC, 45 had at least 1 mutation, including 14 cases of mutation in ion channel genes. In a complementary analysis including 16 additional patients with ion channel gene mutations, for a total of 30 patients with ion channel gene mutation, we found that those patients had higher median LV ejection fraction (60% vs 40%; P < .001) and more biventricular noncompaction (53.1% vs 18.5%; P < .001) than the 81 other patients with LVNC. Among them, both the 19 patients with an HCN4 mutation and the 11 patients with an RYR2 mutation presented with a higher LV ejection fraction and more frequent biventricular noncompaction than the 81 patients with LVNC but with no mutation in the ion channel gene, but only patients with HCN4 mutation presented with a lower heart rate. CONCLUSIONS: Ion channel gene mutations should be searched systematically in patients with LVNC associated with either bradycardia or biventricular noncompaction, particularly when LV systolic function is preserved. Identifying causative mutations is of utmost importance for genetic counselling of at-risk relatives of patients affected by LVNC.


Assuntos
Insuficiência Cardíaca , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/genética , Miocárdio Ventricular não Compactado Isolado , Proteínas Musculares/genética , Canais de Potássio/genética , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Genótipo , Humanos , Canais Iônicos , Miocárdio Ventricular não Compactado Isolado/diagnóstico por imagem , Miocárdio Ventricular não Compactado Isolado/genética , Mutação , Fenótipo , Função Ventricular Esquerda
6.
Hum Mutat ; 41(4): 850-859, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31930659

RESUMO

Recently, four SCN5A mutations have been associated with Multifocal Ectopic Purkinje-related Premature Contractions (MEPPC), a rare cardiac syndrome combining polymorphic ventricular arrhythmia with dilated cardiomyopathy (DCM). Here, we identified a novel heterozygous mutation in SCN5A (c.611C>A, pAla204Glu) in a young woman presenting with polymorphic premature ventricular contractions (PVCs) and DCM. After failure of antiarrhythmic drugs and an attempt of radiofrequency catheter ablation showing three exit-sites of PVCs, all with presystolic Purkinje potentials, a treatment by hydroquinidine was tried, leading to an immediate and spectacular disappearance of all PVCs and normalization of cardiac function. Electrophysiological studies showed that Nav 1.5-A204E mutant channels exhibited a significant leftward shift of 8 mV of the activation curve, leading to a larger hyperpolarized window current when compared to wild-type. Action potential modeling using Purkinje fiber and ventricular cell models predicted an arrhythmogenic effect predominant in Purkinje fibers for the A204E mutation. Comparison with other MEPPC-associated Nav 1.5 mutations revealed a common electrophysiological pattern of abnormal voltage-dependence of activation leading to a larger hyperpolarized window current as a shared biophysical mechanism of this syndrome. These features of the mutant sodium channels are likely to be responsible for the hyperexcitability of the fascicular-Purkinje system observed in patients with MEPPC.


Assuntos
Estudos de Associação Genética , Predisposição Genética para Doença , Ramos Subendocárdicos/metabolismo , Ramos Subendocárdicos/fisiopatologia , Complexos Ventriculares Prematuros/diagnóstico , Complexos Ventriculares Prematuros/etiologia , Adolescente , Alelos , Sequência de Bases , Análise Mutacional de DNA , Eletrocardiografia , Feminino , Mutação com Ganho de Função , Estudos de Associação Genética/métodos , Testes Genéticos , Genótipo , Humanos , Imageamento por Ressonância Magnética , Canal de Sódio Disparado por Voltagem NAV1.5 , Fenótipo , Complexos Ventriculares Prematuros/tratamento farmacológico
7.
Clin Genet ; 95(3): 356-367, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30471092

RESUMO

Left ventricular non-compaction (LVNC) is a cardiomyopathy that may be of genetic origin; however, few data are available about the yield of mutation, the spectrum of genes and allelic variations. The aim of this study was to better characterize the genetic spectrum of isolated LVNC in a prospective cohort of 95 unrelated adult patients through the molecular investigation of 107 genes involved in cardiomyopathies and arrhythmias. Fifty-two pathogenic or probably pathogenic variants were identified in 40 patients (42%) including 31 patients (32.5%) with single variant and 9 patients with complex genotypes (9.5%). Mutated patients tended to have younger age at diagnosis than patients with no identified mutation. The most prevalent genes were TTN, then HCN4, MYH7, and RYR2. The distribution includes 13 genes previously reported in LVNC and 10 additional candidate genes. Our results show that LVNC is basically a genetic disease and support genetic counseling and cardiac screening in relatives. There is a large genetic heterogeneity, with predominant TTN null mutations and frequent complex genotypes. The gene spectrum is close to the one observed in dilated cardiomyopathy but with specific genes such as HCN4. We also identified new candidate genes that could be involved in this sub-phenotype of cardiomyopathy.


Assuntos
Cardiomiopatias/diagnóstico , Cardiomiopatias/genética , Estudos de Associação Genética , Heterogeneidade Genética , Predisposição Genética para Doença , Sequenciamento de Nucleotídeos em Larga Escala , Adulto , Alelos , Biomarcadores , Biologia Computacional/métodos , Ecocardiografia , Feminino , Estudos de Associação Genética/métodos , Variação Genética , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Linhagem , Fenótipo , Disfunção Ventricular Esquerda/diagnóstico , Disfunção Ventricular Esquerda/genética
8.
Clin Genet ; 96(4): 317-329, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31245841

RESUMO

Pathogenic variants in FLNC encoding filamin C have been firstly reported to cause myopathies, and were recently linked to isolated cardiac phenotypes. Our aim was to estimate the prevalence of FLNC pathogenic variants in subtypes of cardiomyopathies and to study the relations between phenotype and genotype. DNAs from a cohort of 1150 unrelated index-patients with isolated cardiomyopathy (700 hypertrophic, 300 dilated, 50 restrictive cardiomyopathies, and 100 left ventricle non-compactions) have been sequenced on a custom panel of 51 cardiomyopathy disease-causing genes. An FLNC pathogenic variant was identified in 28 patients corresponding to a prevalence ranging from 1% to 8% depending on the cardiomyopathy subtype. Truncating variants were always identified in patients with dilated cardiomyopathy, while missense or in-frame indel variants were found in other phenotypes. A personal or family history of sudden cardiac death (SCD) was significantly higher in patients with truncating variants than in patients carrying missense variants (P = .01). This work reported the first observation of a left ventricular non-compaction associated with a unique probably causal variant in FLNC which highlights the role of FLNC in cardiomyopathies. A correlation between the nature of the variant and the cardiomyopathy subtype was observed as well as with SCD risk.


Assuntos
Cardiomiopatias/diagnóstico , Cardiomiopatias/genética , Filaminas/genética , Estudos de Associação Genética , Predisposição Genética para Doença , Variação Genética , Alelos , Cardiomiopatias/epidemiologia , Ecocardiografia , Eletrocardiografia , Feminino , Testes Genéticos , Genótipo , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Imageamento por Ressonância Magnética , Masculino , Mutação , Linhagem , Fenótipo , Prevalência , Análise de Sequência de DNA
9.
Reprod Biomed Online ; 35(4): 372-378, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28711302

RESUMO

Chromosomal translocations and other balanced rearrangements, although usually associated with a normal phenotype, can lead to the transmission of an abnormal unbalanced genome to the offspring. Balanced and unbalanced spermatozoa, being indistinguishable, cannot be selected or deselected for prior to IVF and pre-implantation genetic diagnosis. Spermatozoa from 16 chromosomal rearrangement carriers were studied. After incubation in a hypo-osmotic solution (hypo-osmotic swelling test, or HOST), spermatozoa were fixed on microscope slides. The chromosomally balanced or unbalanced status corresponding to each observed class of flagellar conformation was evaluated through fluorescent in-situ hybridization (FISH). We show here a specific type of spermatozoa, with a distinct flagellar conformation that was associated with a balanced genetic content. HOST is a simple, low-cost and time-honoured procedure initially developed to distinguish immotile viable from non-viable spermatozoa. We demonstrate that it can also be used to identify genetically balanced spermatozoa in chromosomal rearrangement carriers, with a 96% decrease in the proportion of unbalanced spermatozoa after selection. This may potentially improve reproductive prognosis in affected couples if used prior to pre-implantation genetic diagnosis (PGD), and clinical utility and efficacy should be evaluated in further studies.


Assuntos
Triagem de Portadores Genéticos/métodos , Diagnóstico Pré-Implantação/métodos , Espermatozoides/citologia , Translocação Genética/genética , Segregação de Cromossomos , Feminino , Fertilização in vitro , Humanos , Hibridização in Situ Fluorescente , Cariotipagem , Masculino , Osmose , Motilidade dos Espermatozoides , Cauda do Espermatozoide/ultraestrutura
10.
Europace ; 19(4): 651-659, 2017 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-28431061

RESUMO

AIMS: Mutations in PRKAG2, the gene encoding for the γ2 subunit of 5'-AMP-activated protein kinase (AMPK), are responsible for an autosomal dominant glycogenosis with a cardiac presentation, associating hypertrophic cardiomyopathy (HCM), ventricular pre-excitation (VPE), and progressive heart block. The aim of this study was to perform a retrospective time-to-event study of the clinical manifestations associated with PRKAG2 mutations. METHODS AND RESULTS: A cohort of 34 patients from 9 families was recruited between 2001 and 2010. DNA were sequenced on all exons and flanking sequences of the PRKAG2 gene using Sanger sequencing. Overall, four families carried the recurrent p.Arg302Gln mutation, and the five others carried private mutations among which three had never been reported. In the total cohort, at 40 years of age, the risk of developing HCM was 61%, VPE 70%, conduction block 22%, and sudden cardiac death (SCD) 20%. The global survival at 60 years of age was 66%. Thirty-two per cent of patients (N = 10) required a device implantation (5 pacemakers and 5 defibrillators) at a median age of 66 years, and two patients required heart transplant. Only one patient presented with significant skeletal muscle symptoms. No significant differences regarding the occurrence of VPE, ablation complications, or death incidence were observed between different mutations. CONCLUSION: This study of patients with PRKAG2 mutations provides a more comprehensive view of the natural history of this disease and demonstrates a high risk of cardiac complications. Early recognition of this disease appears important to allow an appropriate management.


Assuntos
Proteínas Quinases Ativadas por AMP/genética , Arritmias Cardíacas/epidemiologia , Arritmias Cardíacas/genética , Cardiomiopatia Hipertrófica/genética , Cardiomiopatia Hipertrófica/mortalidade , Doença de Depósito de Glicogênio/genética , Doença de Depósito de Glicogênio/mortalidade , Adulto , Comorbidade , Feminino , França/epidemiologia , Marcadores Genéticos/genética , Predisposição Genética para Doença/epidemiologia , Predisposição Genética para Doença/genética , Humanos , Masculino , Pessoa de Meia-Idade , Mutação/genética , Polimorfismo de Nucleotídeo Único/genética , Prevalência , Fatores de Risco , Taxa de Sobrevida
11.
Blood ; 124(2): 167-75, 2014 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-24859359

RESUMO

Patients with severe malaria treated with artesunate sometimes experience a delayed hemolytic episode. Artesunate (AS) induces pitting, a splenic process whereby dead parasites are expelled from their host erythrocytes. These once-infected erythrocytes then return to the circulation. We analyzed hematologic parameters in 123 travelers treated with AS for severe malaria. Among 60 nontransfused patients observed for more than 8 days, 13 (22%) had delayed hemolysis. The peak concentration of circulating once-infected erythrocytes was measured during the first week in 21 patients and was significantly higher in 9 patients with delayed hemolysis than in 12 with other patterns of anemia (0.30 vs 0.07; P = .0001). The threshold of 180 million once-infected erythrocytes per liter discriminated patients with delayed hemolysis with 89% sensitivity and 83% specificity. Once-infected erythrocyte morphology analyzed by using ImageStream in 4 patients showed an 8.9% reduction in their projected area, an alteration likely contributing to their shorter lifespan. Delayed clearance of infected erythrocytes spared by pitting during AS treatment is an original mechanism of hemolytic anemia. Our findings consolidate a disease framework for posttreatment anemia in malaria in which delayed hemolysis is a new entity. The early concentration of once-infected erythrocytes is a solid candidate marker to predict post-AS delayed hemolysis.


Assuntos
Antimaláricos/uso terapêutico , Artemisininas/uso terapêutico , Hemólise/efeitos dos fármacos , Malária Falciparum/diagnóstico , Malária Falciparum/tratamento farmacológico , Adulto , Anemia Hemolítica/induzido quimicamente , Anemia Hemolítica/parasitologia , Artesunato , Eritrócitos/efeitos dos fármacos , Eritrócitos/parasitologia , Feminino , Seguimentos , Humanos , Malária Falciparum/mortalidade , Masculino , Pessoa de Meia-Idade , Prognóstico , Resultado do Tratamento , Adulto Jovem
12.
Emerg Infect Dis ; 21(5): 804-12, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25898007

RESUMO

Artesunate is the most effective treatment for severe malaria. However, delayed-onset hemolytic anemia has been observed in ≈20% of travelers who receive artesunate, ≈60% of whom require transfusion. This finding could discourage physicians from using artesunate. We prospectively evaluated a cohort of 123 patients in France who had severe imported malaria that was treated with artesunate; our evaluation focused on outcome, adverse events, and postartesunate delayed-onset hemolysis (PADH). Of the 123 patients, 6 (5%) died. Overall, 97 adverse events occurred. Among the 78 patients who received follow-up for >8 days after treatment initiation, 76 (97%) had anemia, and 21 (27%) of the 78 cases were recorded as PADH. The median drop in hemoglobin levels was 1.3 g/dL; 15% of patients with PADH had hemoglobin levels of <7 g/dL, and 1 required transfusion. Despite the high incidence of PADH, the resulting anemia remained mild in 85% of cases. This reassuring result confirms the safety and therapeutic benefit of artesunate.


Assuntos
Anemia Hemolítica/epidemiologia , Anemia Hemolítica/etiologia , Antimaláricos/efeitos adversos , Artemisininas/efeitos adversos , Malária/complicações , Malária/transmissão , Viagem , Adolescente , Anemia Hemolítica/história , Anemia Hemolítica/mortalidade , Anemia Hemolítica/terapia , Antimaláricos/uso terapêutico , Artemisininas/uso terapêutico , Artesunato , Transfusão de Sangue , Feminino , França/epidemiologia , História do Século XXI , Humanos , Malária/tratamento farmacológico , Malária/mortalidade , Masculino , Resultado do Tratamento
13.
Stem Cell Res ; 74: 103294, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38183888

RESUMO

BCL2-Associated Athanogene 3 (BAG3) gene was identified mutated in patients with dilated cardiomyopathy (DCM), an important cause of heart failure and premature death. BAG3 is a cytoprotective co-chaperonne protein involved in many cellular process with a central role in the maintenance of protostasis. We generated two human induced pluripotent stem cell lines (hiPSc), one carrying the heterozygous, the other the homozygous p.V468M mutation identified in DCM familial cases. All lines expressed pluripotent markers, had normal karyotype, and differentiated into derivatives of the three germ layers. Sudies of hiPSc derived cardiomyocytes will help to understand the role of BAG3 in DCM.


Assuntos
Cardiomiopatia Dilatada , Células-Tronco Pluripotentes Induzidas , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Sistemas CRISPR-Cas/genética , Proteínas Reguladoras de Apoptose/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Mutação/genética , Cardiomiopatia Dilatada/genética
14.
J Cardiovasc Dev Dis ; 11(3)2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38535102

RESUMO

Dilated cardiomyopathy (DCM) is the most common childhood cardiomyopathy and is associated with considerable early mortality. Heart transplantation is often the only viable life-saving option. Pulmonary artery banding (PAB) has been recently proposed as a bridge or alternative to transplantation for DCM. In our cohort, PAB was selectively addressed to heritable DCM or DCM with congenital left ventricle aneurysm (CLVA). This study aimed to describe the clinical evolution and left ventricle reverse remodeling (LVRR) over time (6 months and 1 year after surgery). Ten patients with severe DCM received PAB between 2016 and 2021 and underwent clinical and postoperative echocardiography follow-ups. The median age at PAB was <1 year. The in-hospital mortality was zero. Two patients died two months after PAB of end-stage heart failure. The modified Ross class was improved in the eight survivors with DCM and remained stable in the two patients with CLVA. We observed a positive LVRR (LV end-diastolic diameter Z-score: 8.4 ± 3.7 vs. 2.8 ± 3; p < 0.05; LV ejection fraction: 23.8 ± 5.8 to 44.5 ± 13.1 (p < 0.05)). PAB might be useful as part of the armamentarium available in infants and toddlers with severe DCM not sufficiently responding to medical treatment with limited probability of spontaneous recovery.

15.
Biomedicines ; 12(2)2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38397924

RESUMO

Filamin C-related disorders include myopathies and cardiomyopathies linked to variants in the FLNC gene. Filamin C belongs to a family of actin-binding proteins involved in sarcomere stability. This study investigates the pathogenic impact of the FLNC c.3557C > T (p.Ala1186Val) pathogenic variant associated with an early-onset cytoplasmic body myopathy and cardiomyopathy in three unrelated patients. We performed clinical imaging and myopathologic and genetic characterization of three patients with an early-onset myopathy and cardiomyopathy. Bioinformatics analysis, variant interpretation, and protein structure analysis were performed to validate and assess the effects of the filamin C variant. All patients presented with a homogeneous clinical phenotype marked by a severe contractural myopathy, leading to loss of gait. There was prominent respiratory involvement and restrictive or hypertrophic cardiomyopathies. The Ala1186Val variant is located in the interstrand loop involved in intradomain stabilization and/or interdomain interactions with neighbor Ig-like domains. 3D modeling highlights local structural changes involving nearby residues and probably impacts the protein stability, causing protein aggregation in the form of cytoplasmic bodies. Myopathologic studies have disclosed the prominent aggregation and upregulation of the aggrephagy-associated proteins LC3B and p62. As a whole, the Ala1186Val variant in the FLNC gene provokes a severe myopathy with contractures, respiratory involvement, and cardiomyopathy due to protein aggregation in patients' muscles.

16.
Circ Genom Precis Med ; 17(1): e004285, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38059363

RESUMO

BACKGROUND: Few clinical data are available on NEXN mutation carriers, and the gene's involvement in cardiomyopathies or sudden death has not been fully established. Our objectives were to assess the prevalence of putative pathogenic variants in NEXN and to describe the phenotype and prognosis of patients carrying the variants. METHODS: DNA samples from consecutive patients with cardiomyopathy or sudden cardiac death/sudden infant death syndrome/idiopathic ventricular fibrillation were sequenced with a custom panel of genes. Index cases carrying at least one putative pathogenic variant in the NEXN gene were selected. RESULTS: Of the 9516 index patients sequenced, 31 were carriers of a putative pathogenic variant in NEXN only, including 2 with double variants and 29 with a single variant. Of the 29 unrelated probands with a single variant (16 males; median age at diagnosis, 32.0 [26.0-49.0] years), 21 presented with dilated cardiomyopathy (prevalence, 0.33%), and 3 presented with hypertrophic cardiomyopathy (prevalence, 0.14%). Three patients had idiopathic ventricular fibrillation, and there were 2 cases of sudden infant death syndrome (prevalence, 0.46%). For patients with dilated cardiomyopathy, the median left ventricle ejection fraction was 37.5% (26.25-50.0) at diagnosis and improved with treatment in 13 (61.9%). Over a median follow-up period of 6.0 years, we recorded 3 severe arrhythmic events and 2 severe hemodynamic events. CONCLUSIONS: Putative pathogenic NEXN variants were mainly associated with dilated cardiomyopathy; in these individuals, the prognosis appeared to be relatively good. However, severe and early onset phenotypes were also observed-especially in patients with double NEXN variants. We also detected NEXN variants in patients with hypertrophic cardiomyopathy and sudden infant death syndrome/idiopathic ventricular fibrillation, although a causal link could not be established.


Assuntos
Cardiomiopatias , Cardiomiopatia Dilatada , Cardiomiopatia Hipertrófica , Morte Súbita do Lactente , Fibrilação Ventricular , Masculino , Lactente , Humanos , Adulto , Pessoa de Meia-Idade , Cardiomiopatia Dilatada/genética , Prevalência , Cardiomiopatias/diagnóstico , Fenótipo , Cardiomiopatia Hipertrófica/genética , Cardiomiopatia Hipertrófica/complicações , Morte Súbita Cardíaca/etiologia , Prognóstico , Proteínas dos Microfilamentos/genética
17.
JACC Adv ; 3(3): 100832, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38938828

RESUMO

Background: Patients with likely pathogenic/pathogenic desmoplakin (DSP) variants are poorly characterized. Some of them meet diagnostic criteria for arrhythmogenic right ventricular cardiomyopathy (ARVC), but it is unclear how risk stratification strategies for ARVC perform in this setting. Objectives: The purpose of this study was to characterize arrhythmic outcomes and to test the performance of the recently validated ARVC risk calculator in patients with DSP likely pathogenic/pathogenic variants fulfilling definite 2010 ARVC Task Force Criteria (DSP-TFC+). Methods: DSP-TFC+ patients were enrolled from 20 institutions across 3 continents. Ventricular arrhythmias (VA), defined as a composite of sustained ventricular tachycardia (VT), appropriate implantable cardioverter defibrillator therapies, and ventricular fibrillation/sudden cardiac death events in follow-up, were reported as the primary outcome. We tested the performance of the ARVC risk calculator for VA prediction, reporting c-statistics. Results: Among 252 DSP-TFC+ patients (age 39.6 ± 16.9 years, 35.3% male), 94 (37.3%) experienced VA over 44.5 [IQR: 19.6-78.3] months. Patients with left ventricle involvement (n = 194) were at higher VA risk (log-rank P = 0.0239). History of nonsustained VT (aHR 2.097; P = 0.004) showed the strongest association with VA occurrence during the first 5-year follow-up. Neither age (P = 0.723) nor male sex (P = 0.200) was associated with VAs at follow-up. In 204 patients without VA at diagnosis, incident VA rate was high (32.8%; 7.37%/y). The ARVC risk calculator performed poorly overall (c-statistic 0.604 [0.594-0.614]) and very poorly in patients with left ventricular disease (c-statistic 0.558 [0.556-0.560]). Conclusions: DSP-TFC+ patients are at substantial risk for VAs. The ARVC risk calculator performs poorly in DSP-TFC+ patients suggesting need for a gene-specific risk algorithm. Meanwhile, DSP-TFC+ patients with nonsustained VT should be considered as high-risk.

19.
Cells ; 12(2)2023 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-36672271

RESUMO

A single missense variant of the TMPO/LAP2α gene, encoding LAP2 proteins, has been associated with cardiomyopathy in two brothers. To further evaluate its role in cardiac muscle, we included TMPO in our cardiomyopathy diagnostic gene panel. A screening of ~5000 patients revealed three novel rare TMPO heterozygous variants in six males diagnosed with hypertrophic or dilated cardiomypathy. We identified in different cellular models that (1) the frameshift variant LAP2α p.(Gly395Glufs*11) induced haploinsufficiency, impeding cell proliferation and/or producing a truncated protein mislocalized in the cytoplasm; (2) the C-ter missense variant LAP2α p.(Ala240Thr) led to a reduced proximity events between LAP2α and the nucleosome binding protein HMGN5; and (3) the LEM-domain missense variant p.(Leu124Phe) decreased both associations of LAP2α/ß with the chromatin-associated protein BAF and inhibition of the E2F1 transcription factor activity which is known to be dependent on Rb, partner of LAP2α. Additionally, the LAP2α expression was lower in the left ventricles of male mice compared to females. In conclusion, our study reveals distinct altered properties of LAP2 induced by these TMPO/LAP2 variants, leading to altered cell proliferation, chromatin structure or gene expression-regulation pathways, and suggests a potential sex-dependent role of LAP2 in myocardial function and disease.


Assuntos
Cardiomiopatias , Cromossomos , Feminino , Masculino , Camundongos , Animais , Cardiomiopatias/genética , Cromatina , Fenótipo
20.
Stem Cell Res ; 58: 102616, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34883448

RESUMO

Loss-of-function (LoF) mutations in FLNC are strongly associated with dilated cardiomyopathy (DCM). Using CRISPR/Cas9 mediated edition in an healthy donor derived iPSC (ICAN-403.3) we subcloned 1 iPSC line harboring LoF mutation in FLNC. All lines are fully pluripotent and isogenic except at edited site where it presents a homozygous (ICAN-FLNC42.1) deletion of splice site leading to skipping of exon 42 traduced into a short filamin form with reduced expression in derived cardiomyocytes. This line would serve for FLNC mutation DCM modeling after differentiation into cardiocytes or beating organoids.


Assuntos
Cardiomiopatia Dilatada , Células-Tronco Pluripotentes Induzidas , Sistemas CRISPR-Cas/genética , Cardiomiopatia Dilatada/genética , Éxons/genética , Filaminas/genética , Filaminas/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Mutação
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