Clinical Impact of Secondary Risk Factors in TTN-Mediated Dilated Cardiomyopathy.
Ontology highlight
ABSTRACT:
SUBMITTER: Giudicessi JR
PROVIDER: S-EPMC8284363 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Truncating variants in TTN (TTNtv), coding for the largest structural protein in the sarcomere, contribute to the largest portion of familial and ambulatory dilated cardiomyopathy (DCM). TTN haploinsufficiency caused by TTNtv is suggested as the disease mechanism. However, it is unclear whether TTN insufficiency causes DCM. Moreover, it is unknown whether modulation of downstream pathways serves as a therapeutic strategy for DCM caused by TTN insufficiency. Here, we show that reduction of cardiac Ttn expression by adeno-associated virus mediated shRNA (Ttn shRNA) generated DCM in mouse, demonstrating impaired cardiac performance, enlarged left ventricle (LV) and reduced LV wall thickness. A screen of 10 dysregulated and selected genes identified that Yin Yang 1 (Yy1) significantly suppressed DCM caused by Ttn shRNA. Gene profiling by RNAseq showed Yy1 modulated cell growth related genes. Ttn insufficiency activated cardiomyocyte cell cycle reentry by upregulating of Ccnd1 and Ccnd2. Cardiomyocytes activated by Ttn insufficiency did not advance to S phase by EdU incorporation assay. Yy1 promoted cardiomyocyte cell cycle by further enhancing Ccnd1 and Ccnd2 and increasing DNA replication without undergoing cell division. Importantly, upregulation of Ccnd1 and Ccnd2 suppressed DCM caused by Ttn insufficiency. Our findings demonstrate that DCM caused by Ttn insufficiency can be treated by therapeutically promoting cardiac cell cycle.
| S-EPMC6841687 | biostudies-literature
Project description:A 6-month-old infant boy presented with symptomatic heart failure. Dilated cardiomyopathy was found in association with a mutation in TTN. Structural heart disease included novel septation of the left ventricle with a fenestrated membrane resulting from aberrant congenital mitral valve apparatus formation. (Level of Difficulty: Advanced.).
| S-EPMC8571792 | biostudies-literature
Project description:Background: Mutations in the TTN gene are the most common causes of dilated cardiomyopathy (DCM). The clinical significance of TTN gene variants remains inadequately understood. Methods: Whole-exome sequencing and phenotypic characterisation were performed, and patients were followed up for a median of 44 months. Results: We analyzed the association of the TTN variants with the clinical outcomes in a prospective study of 1,041 patients with sporadic DCM. TTN truncating variants (tTTN) were detected in 120 (11.5%) patients as compared with 2.4/10,000 East Asian populations in the Genome Aggregation Database (GnomAD; p < 0.0001). Pathogenic TTN missense variants were also enriched in DCM as compared with the GnomAD populations (27.6 vs. 5.9%, p < 0.0001). DCM patients with tTTN had a lower left ventricular ejection fraction (28.89 ± 8.72 vs. 31.81 ± 9.97, p = 0.002) and a lower frequency of the left bundle branch block (3.3 vs. 11.3%, p = 0.011) than those without or with mutations in other known causal genes (OCG). However, tTTN were not associated with the composite primary endpoint of cardiac death and heart transplantation during the follow-up period [adjusted hazard ratio (HR): 0.912; 95% confidence interval: 0.464-1.793; p = 0.790]. There was also no sex-dependent effect. Concomitant tTTN and pathogenic variants in OCG were present in only eight DCM patients and did not affect the outcome. Conclusion: The phenotype of DCM caused by tTTN, major causes of sporadic DCM, is not distinctly different from those caused by other causal genes for DCM.
| S-EPMC8120103 | biostudies-literature
Project description:BACKGROUND:Pathogenic variants in TTN (OMIM 188840), encoding the largest human protein, are known to cause dilated cardiomyopathy and several forms of skeletal myopathy. The clinical interpretation of TTN variants is challenging, however, due to the frequency of missense changes, variable testing and reporting practices in commercial laboratories, and incomplete understanding of the spectrum of TTN-related disease. METHODS:We report a heterozygous TTN deletion segregating in a family with an unusual skeletal myopathy phenotype associated with facial weakness, gait abnormality, and dilated cardiomyopathy. RESULTS:A novel 16.430 kb heterozygous deletion spanning part of the A- and M-bands of TTN was identified in the proband and his symptomatic son, as well as in an additional son whose symptoms were identified on clinical evaluation. The deletion was found to be de novo in the proband. CONCLUSION:Pathogenic variants in TTN may be an unrecognized cause of skeletal myopathy phenotypes, particularly when accompanied by dilated cardiomyopathy.
| S-EPMC6825852 | biostudies-literature
Project description:Dilated cardiomyopathy (DCM), defined by left ventricular (LV) enlargement associated with impaired cardiac performance, is a major cause of heart failure (HF). This results in a dilated, thin-walled left ventricle that fails to supply sufficient blood to the body. Truncating variants in TTN (TTNtv), coding for the largest structural protein in the sarcomere, contribute to the largest portion of familial and ambulatory DCM. The mechanisms for how TTNtv lead to cardiac dilation are unclear. Here, we show that reduction of Ttn expression by shRNA (Ttn shRNA) generated DCM in both mouse and rat. Ttn shRNA transduced mice developed typical DCM manifestations including impaired cardiac performance, enlarged LV and reduced LV wall thickness. Gene profiling indicates cardiac metabolism, cell proliferation and survival related genes are significantly dysregulated in Ttn shRNA-induced DCM. TUNEL assay showed Ttn shRNA induced a significant increase of cardiac cell apoptosis. A screen of 15 dysregulated downstream genes identified candidates, including Esrra, Esrrb and Yy1 significantly suppressed Ttn shRNA-induced cardiac dilation and/or DCM. Ttn shRNA induced cardiac cell apoptosis was ameliorated by Yy1. Importantly, by inducing D-type cyclin, Yy1 initiated cardiomyocyte cell cycle reentry facilitating the restoration of cardiac performance. Our findings demonstrate that DCM caused by Ttn insufficiency can be treated by therapeutically enhancing cardiac cell proliferation and survival.
2020-03-26 | GSE112319 | GEO
Project description:Idiopathic dilated cardiomyopathy (DCM) is a common cardiomyopathy with the prevalence of 1:250, and at least one-third of all the cases are inherited. Mutations in the TTN gene are considered as the most frequent cause of inherited DCM and cover 10-30% of the cases. The studies were mainly focused on the adult or mixed age group of patients with DCM. The mutation rate in the TTN gene, the characteristics of manifestations and their prognostic significance in childhood have not been studied. To determine TTN mutation rate in children with DCM and the relevance of including this gene in the DNA diagnostic protocol for paediatric DCM, complete clinical and instrumental examination of 36 DCM patients (up to 18 years) with the manifestation of the disease was conducted in specialised cardiology centres. Molecular genetic testing included sequencing of coding and adjacent regulatory regions of the major cardiac TTN isoform N2BA using IonTorrent ™ semiconductor sequencing (for 25 isolated cases) and trio whole exome sequencing (trio WES)on the Illumina platform (for 11 family cases). Our pilot group included 36 probands with DCM diagnosis first established on the basis of the generally accepted criteria at the age of 5 days to 18 years(average age: 6.5 years). The sex ratio (M:F) was 23: 8. There were 25 sporadic DCM cases and 11 cases of familial DCM (at least one of the parents and/or siblings were also diagnosed with DCM). The only likely pathogenic truncating variant p.Arg33703*in the TTN gene (TTNtv) was found in a 16-year-oldmale proband out of 36 (3%). Apparently, TTN-dependent forms of DCMs manifest later at a young (but older than 18 years) or more mature age, and TTN gene cannot be considered as the first-line genetic testing for DCM in the paediatric group, despite several studies have reported a generally high mutation rate in this gene with DCM. Further research is needed to compare the representation of mutations in the TTN gene in different age groups of DCM patients.
| S-EPMC6848193 | biostudies-literature
Project description:Familial dilated cardiomyopathy (DCM) is a heterogeneous disease; although 30 disease genes have been discovered, they explain only no more than half of all cases; in addition, the causes of intra-familial variability in DCM have remained largely unknown. In this study, we exploited the use of whole-exome sequencing (WES) to investigate the causes of clinical variability in an extended family with 14 affected subjects, four of whom showed particular severe manifestations of cardiomyopathy requiring heart transplantation in early adulthood. This analysis, followed by confirmative conventional sequencing, identified the mutation p.K219T in the lamin A/C gene in all 14 affected patients. An additional variant in the gene for titin, p.L4855F, was identified in the severely affected patients. The age for heart transplantation was substantially less for LMNA:p.K219T/TTN:p.L4855F double heterozygotes than that for LMNA:p.K219T single heterozygotes. Myocardial specimens of doubly heterozygote individuals showed increased nuclear length, sarcomeric disorganization, and myonuclear clustering compared with samples from single heterozygotes. In conclusion, our results show that WES can be used for the identification of causal and modifier variants in families with variable manifestations of DCM. In addition, they not only indicate that LMNA and TTN mutational status may be useful in this family for risk stratification in individuals at risk for DCM but also suggest titin as a modifier for DCM.
| S-EPMC3778353 | biostudies-literature
Project description:Pulmonary hypertension (PH) in patients with heart failure (HF) contributes to a poorer prognosis. However, in those with dilated cardiomyopathy (DCM), the true prevalence and role of PH is unclear. Therefore, this study aimed to analyze the profile of DCM patients at various levels of PH risk, determined via echocardiography, and its impact on outcomes. The 502 DCM in- and out-patient records were retrospectively analyzed. Information on patient status was gathered after 45.9 ± 31.3 months. Patients were divided into 3 PH-risk groups based on results from echocardiography measurements: low (L, n = 239, 47.6%), intermediate (I, n = 153, 30.5%), and high (H, n = 110, 21.9%). Symptom duration, atrial fibrillation, ventricular tachyarrhythmia, ejection fraction, right atrial area, and moderate or severe mitral regurgitation were found to be independently associated with PH risk. During the follow-up period, 83 (16.5%) DCM patients died: 29 (12.1%) in L, 31 (20.3%) in I, and 23 (20.9%) in H. L-patients had a significantly lower risk of all-cause death (L to H: HR 0.55 (95%CI 0.32-0.98), p = 0.01), while no differences in prognosis were found between I and H. In conclusion, over one in five DCM patients had a high PH risk, and low PH risk was associated with better prognoses.
| S-EPMC7355437 | biostudies-literature
Project description:BackgroundCocaine is a potent sympathomimetic agent associated with the development of possible fatal cardiovascular complications. Dysrhythmias, acute myocardial infarction, hypertension and dilated cardiomyopathy are just some of many cardiovascular effects related to the abuse of cocaine.Case presentationA 38-year-old Hispanic male with a past medical history of hypertension presented with a chief complaint of progressive shortness of breath. The patient confessed to the use of cocaine for almost 18 years once per week. On examination he was hypertensive and tachycardic with a systolic murmur over the 5th intercostal space at the level of the left mid-clavicular line. Laboratory workup revealed an elevated Brain natriuretic peptide; urine toxicology was positive for cocaine. 2D-echocardiogram showed dilated cardiomyopathy. Cardiac catheterization excluded angioischemic cause. He was managed medically and subsequently discharged with drug rehabilitation. On follow-up diagnostic evaluation after 5 months of cocaine cessation, his ejection function improved significantly.ConclusionThe exact incidence of cocaine related cardiomyopathy is unknown and likely underreported. The clinical course is abrupt and comparatively similar to other types of cardiomyopathy. The management is like other forms of cardiomyopathy; however β-blockers should be avoided. The myocardial dysfunction is reversible with abstaining from additional cocaine ingestion. Non-invasive testing should be performed after several months to re-evaluate the treatment response.
| S-EPMC3866926 | biostudies-literature
Project description:AimsThe aims of this paper were to investigate the analytical performance of the nine prognostic scales commonly used in heart failure (HF), in patients with dilated cardiomyopathy (DCM), and to develop a unique prognostic model tailored to DCM patients.Methods and resultsThe hospital and outpatient records of 406 DCM patients were retrospectively analysed. The information on patient status was gathered after 48.2 ± 32.0 months. Tests were carried out to ascertain the prognostic accuracy in DCM using some of the most frequently applied HF prognostic scales (Barcelona Bio-Heart Failure, Candesartan in Heart Failure-Assessment of Reduction in Mortality and Morbidity, Studio della Streptochinasi nell'Infarto Miocardico-Heart Failure, Eplerenone in Mild Patients Hospitalization and Survival Study in Heart Failure, Meta-Analysis Global Group in Chronic Heart Failure, MUerte Subita en Insuficiencia Cardiaca, Organized Program to Initiate Lifesaving Treatment in Hospitalized Patients With Heart Failure, Seattle Heart Failure Model) and one dedicated to DCM, that of Miura et al. At follow-up, 70 DCM patients (17.2%) died. Most analysed scores substantially overestimated the mortality risk, especially in survivors. The prognostic accuracy of the scales were suboptimal, varying between 60% and 80%, with the best performance from Barcelona Bio-Heart Failure and Seattle Heart Failure Model for 1-5 year mortality [areas under the receiver operating curve 0.792-0.890 (95% confidence interval 0.725-0.918) and 0.764-0.808 (95% confidence interval 0.682-0.934), respectively].Based on our accumulated data, a self-developed DCM prognostic model was constructed. The model consists of age, gender, body mass index, symptoms duration, New York Heart Association class, diabetes mellitus, prior stroke, abnormal liver function, dyslipidaemia, left bundle branch block, left ventricle end-diastolic diameter, ejection fraction, N terminal pro brain natriuretic peptide, haemoglobin, estimated glomerular filtration rate, and pharmacological and resynchronisation therapy. This newly created prognostic model outperformed the analysed HF scales.ConclusionsAn analysis of various HF prognostic models found them to be suboptimal for DCM patients. A self-developed DCM prognostic model showed improved performance over the nine other models studied. However, further validation of the prognostic model in different DCM populations is required.
| S-EPMC7524139 | biostudies-literature