Search Results (262)

SLC25A4, solute carrier family 25 member 4, gene is a member of the mitochondrial carrier subfamily within the solute carrier protein family. Pathogenic variants in SLC25A4 are associated with a spectrum of mitochondrial disorders that exhibit variable inheritance patterns and clinical manifestations. Specifically, dominantly inherited variants are typically associated with progressive external ophthalmoplegia with mitochondrial DNA deletions, recessively inherited variants are linked to myopathy and cardiomyopathy, and de novo variants can result in early-onset fatal disease presentations. In this study, we aimed to identify and characterize the disease-causing mutation(s) in a nine-year-old female patient from a consanguineous Saudi family. The patient was asymptomatic until the age of 3 years, when she presented with cardiomyopathy and myopathy. Comprehensive genetic analysis inclusive of whole exome sequencing and segregation analysis using Sanger sequencing identified an SLC25A4 variant (NM_001151.4: exon 2: c.112-1G>C) as the most likely cause of the disease. To assess transcript-level effects, we performed RT-PCR on RNA extracted from the patient’s cultured lymphoblast cell lines (LCLs) and fibroblast cell lines (FCLs). RT-PCR analysis demonstrated that the variant causes aberrant splicing, resulting in a 6 bp in-frame deletion (p.Gln37_Val38del) in the ANT1 protein. Quantitative RT-PCR demonstrated reduced SLC25A4 transcript levels in both FCLs and LCLs. Quantitative PCR analysis of mitochondrial DNA demonstrated a trend toward increased mtDNA copy number in patient-derived FCLs compared with controls, suggesting a possible compensatory response to mitochondrial dysfunction. Furthermore, Seahorse assays revealed marked reductions in both oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) in patient-derived FCLs compared with controls. These findings expand the molecular and functional spectrum of SLC25A4-associated disease and may inform clinical practice, including genetic interventions such as preimplantation genetic diagnosis, premarital genetic screening, targeted genetic counseling, and cascade testing of at-risk family members. Full article

Background/Objectives: Dilated cardiomyopathy (DCM) is a genetically heterogeneous myocardial disorder. Emerging evidence suggests that some genes implicated in DCM may also be associated with neurological disorders, supporting the concept of genetic pleiotropy. This study explored the intersection between cardiac and neurological genetics, with the aim of identifying candidate genes that may contribute to shared pathogenic pathways linking these clinically distinct conditions. Methods: We performed exome sequencing in 149 patients with echocardiographically confirmed DCM and subsequently applied an in silico filter to a predefined list of 211 genes associated with inherited cardiomyopathies. Variants were classified according to the American College of Medical Genetics and Genomics (ACMG) criteria. Genes with validated evidence for DCM according to the Clinical Genome Resource (ClinGen) were further investigated through the Human Gene Mutation Database (HGMD) and a focused literature review to identify reported associations with neurological disorders. Results: Genetic variants in DCM-associated genes were identified in 105 patients. Overall, 137 variants were detected, including pathogenic variants and variants of uncertain significance. The most frequently involved genes were TTN, FLNC, and MYH6. Several DCM-associated genes also showed reported associations with neurological disorders, including autism spectrum disorder, Alzheimer’s disease, Parkinson’s disease, epilepsy, and schizophrenia. Among them, TTN, FLNC, RYR2, and SCN5A displayed the broadest overlap between cardiac and neurological phenotypes. Conclusions: These descriptive findings show that variants were most frequently observed in TTN, FLNC, and MYH6 and that several genes included in the ClinGen DCM curation framework have also been independently reported in neurological disorders. Because most identified variants were VUS and no control group or systematic neurological phenotyping was available, the findings indicate gene-level co-annotation only and do not establish variant enrichment, shared pathogenic mechanisms, or clinical overlap. Full article

There are several forms of monoallelic expression, in which the 50:50 ratio in the expression activity of each of the two copies of the gene is disrupted. This review focuses on the phenomenon of random autosomal monoallelic expression (aRME), a process in which only one of the two alleles is transcribed in a single cell, and the allele choice is not determined by the parental origin. One of the central problems in studying this phenomenon is the differentiation of the two forms of aRME: clonal, in which the expression pattern is mitotically inherited, and stochastic, when the allele choice can change over time due to transcriptional bursting. Distinguishing these events is methodologically challenging: divergent experimental approaches and the lack of standardized detection criteria have produced strikingly contradictory estimates of aRME prevalence. Furthermore, single-cell transcriptomic approaches are particularly susceptible to technical artefacts that can generate false-positive monoallelic calls, complicating the distinction between heritable and transient states. In this review, we critically evaluate the evidence for clonal and stochastic aRME, examine the epigenetic mechanisms proposed to maintain monoallelic expression, and discuss its clinical significance, focusing on the role of monoallelic expression in the penetrance of autosomal dominant diseases (including congenital immune disorders and cardiomyopathy), neurodevelopmental disorders, and cancer progression. Full article

Hypertrophic cardiomyopathy (HCM) is a common inherited myocardial disorder and a leading cause of sudden cardiac death (SCD) across all age groups. Accurate risk stratification remains a clinical challenge, as conventional algorithms fail to fully capture the heterogeneous arrhythmic substrate of the disease. In recent years, cardiac imaging has emerged as a pivotal tool for refining SCD prediction by providing detailed structural, functional, and tissue-characterisation data. This review offers a comprehensive synthesis of imaging-derived predictors of SCD in HCM. We examine established echocardiographic markers, including maximal left ventricular wall thickness, left ventricular ejection fraction and left ventricular outflow tract obstruction, together with advanced cardiovascular magnetic resonance parameters such as late gadolinium enhancement and apical aneurysm detection. In addition, we discuss the emerging role of extracellular volume expansion, quantitative mapping techniques, and strain abnormalities within the framework of contemporary risk stratification models. By bridging imaging biomarkers with underlying pathophysiological mechanisms, this review highlights current evidence, limitations, and future directions to improve precision in SCD risk assessment in HCM. Full article

Arrhythmogenic cardiomyopathy (ACM/ARVC) is an inherited myocardial disease characterized by progressive fibro-fatty replacement, ventricular arrhythmias, and an increased risk of sudden cardiac death. In addition to mutations in desmosomal genes, growing evidence suggests that microRNAs (miRNAs) actively contribute to disease pathogenesis by regulating key processes such as fibrosis, cell adhesion, and cardiac remodeling. This systematic review analyzed the main miRNAs identified in studies of human cardiac tissue and animal models of ARVC. Materials and Methods: Studies based on human myocardial tissue analysis (including autopsy and biopsy samples) and animal models of arrhythmogenic cardiomyopathy were included, using RNA sequencing, small RNA sequencing, miRNA arrays, and RT-qPCR. Studies on circulating miRNAs and narrative reviews were excluded. miRNAs were analyzed in relation to their functional pathways and their role in disease pathogenesis. Results: The synthesis of studies on human and animal cardiac tissue reveals a consistent miRNA signature associated with arrhythmogenic cardiomyopathy. MiR-21-5p and miR-29b-3p are associated with fibrosis and extracellular matrix remodeling, whereas miR-133a-b and miR-130a are linked to cardiomyocyte integrity loss and desmosomal dysfunction. A second group of miRNAs, including miR-217-5p, miR-708-5p, and miR-135b, regulates key pathways such as Wnt/β-catenin and Hippo signaling, contributing to structural remodeling and loss of cellular identity. Furthermore, downregulation of miR-499-5p is associated with mitochondrial dysfunction and cellular vulnerability, while the miR-142-3p, miR-182-5p, and miR-183-5p clusters contribute to differential molecular signatures compared with other cardiomyopathies. Overall, miRNAs converge on three main pathogenic axes: myocardial fibrosis, desmosomal impairment, and remodeling of cellular signaling pathways. Conclusions: The available evidence indicates that arrhythmogenic cardiomyopathy is regulated by a coordinated network of miRNAs that actively drives myocardial damage progression. These miRNAs represent not only biomarkers but also functional mediators of disease, suggesting potential diagnostic and therapeutic applications based on tissue-specific molecular signatures, including in post-mortem settings. Full article

Hypertrophic cardiomyopathy (HCM) is the most common inherited myocardial disorder and a major cause of heart failure (HF) and sudden cardiac death. Although sarcomeric gene mutations initiate the disease, increasing evidence identifies oxidative stress, mitochondrial dysfunction, and maladaptive nutrient signaling as key drivers of disease progression. Enhanced reactive oxygen species (ROS) production in HCM promotes energetic impairment, calcium mishandling, fibrosis, and the activation of pro-hypertrophic pathways, while disrupting protein quality control and endothelial function. Despite recent therapeutic advances, effective disease-modifying strategies targeting these molecular mechanisms remain limited. Sodium–glucose cotransporter 2 inhibitors (SGLT2i), originally developed for type 2 diabetes, have demonstrated robust cardioprotective effects in HF independent of glycemic control. Beyond their renal actions, SGLT2i modulate myocardial metabolism, reduce oxidative stress, improve mitochondrial function, restore sodium and calcium homeostasis, and attenuate inflammation and maladaptive mTOR activation. Emerging preclinical and translational data suggest that these pleiotropic mechanisms may counteract key pathophysiological processes underlying HCM. This review summarizes the molecular interplay between oxidative stress and hypertrophic remodeling in HCM and explores the rationale for SGLT2 inhibition as a potential disease-modifying therapeutic strategy. Full article

Sudden cardiac death (SCD) in athletes often represents the first manifestation of an underlying inherited cardiovascular disorder exposed by adrenergic stress, altered calcium cycling, mechanical loading, and metabolic demand during intense exercise. This review focuses on the molecular architecture that links genotype to arrhythmogenic phenotype in athletes, emphasizing sarcomeric force generation and energetic inefficiency in hypertrophic cardiomyopathy, desmosomal failure and Hippo/Wnt/transforming growth factor-beta (TGF-β) signaling in arrhythmogenic cardiomyopathy, and ion-channel and calcium/calmodulin-dependent protein kinase II (CaMKII)calcium handling abnormalities in inherited channelopathies. This review further examines how exercise-induced physiological remodeling intersects with these pathways through insulin-like growth factor-1 (IGF-1)/phosphoinositide 3-kinase (PI3K)/ protein kinase B (AKT) signaling, mitochondrial biogenesis, oxidative stress, inflammatory signaling, and epigenetic regulation. Attention is given to the molecular basis of genotype-positive/phenotype-negative states, variable penetrance, and exercise-mediated disease expression. Finally, the integration of molecular biology with genomic data, polygenic risk, and emerging digital phenotyping is discussed to refine mechanism-based risk stratification and identify future therapeutic targets for prevention of SCD in athletes. Full article

Sudden unexpected death in infancy (SUDI) remains a major challenge in pediatric pathology and forensic medicine. Despite advances in diagnostic techniques, many cases are still classified as unexplained and labeled as sudden infant death syndrome (SIDS). Increasing evidence suggests that a proportion of these deaths may be due to “hidden” causes not detectable through routine post-mortem examination. A narrative review of the literature (2000–2026) was conducted using PubMed and Scopus, focusing on under-recognized causes of SUDI and their diagnostic implications. Relevant studies were selected and organized into major pathological and forensic categories. Hidden causes of SUDI include a wide spectrum of conditions. Cardiac disorders—such as myocarditis, cardiomyopathies, and inherited arrhythmogenic syndromes—are frequently implicated and may require molecular autopsy for detection. Infectious diseases, often presenting with minimal or nonspecific findings, represent another important category, particularly viral and bacterial infections. Inborn errors of metabolism, especially fatty acid oxidation defects, may lead to sudden death in the absence of specific autopsy findings, highlighting the role of biochemical analyses. Neuropathological abnormalities involving brainstem regulatory systems may contribute to impaired autonomic control. Environmental, toxicological, and medico-legal factors—including unsafe sleep conditions, toxic exposures, and inflicted injury—must also be considered. SUDI is a multifactorial entity in which many unexplained deaths may be attributable to identifiable but overlooked conditions. A standardized, multidisciplinary approach integrating autopsy, ancillary investigations, and molecular diagnostics is essential to improve diagnostic accuracy and support prevention strategies. Full article

Hypertrophic Cardiomyopathy (HCM) is one of the most common inherited cardiomyopathies and remains an important cause of ventricular arrhythmias and sudden cardiac death (SCD), particularly in younger individuals. Although the annual incidence of arrhythmic death is relatively low in contemporary cohorts, identifying those patients who may benefit from primary prevention with an implantable cardioverter-defibrillator (ICD) remains a major clinical challenge. Current risk stratification strategies rely on two principal paradigms. The European approach is centered on the HCM Risk-SCD score, whereas the American approach is mainly based on major clinical risk markers. Both strategies have important strengths and limitations, reflecting the persistent difficulty of accurately predicting arrhythmic events in such a heterogeneous disease. The HCM Risk-SCD score has demonstrated robust external validation and high specificity for identifying patients at higher risk, but it may fail to recognize some vulnerable individuals who remain below conventional treatment thresholds. For this reason, several additional risk modifiers have gained increasing relevance in contemporary practice. Among them, extensive late gadolinium enhancement, left ventricular systolic dysfunction, apical aneurysm, and clinically meaningful genetic findings may provide important incremental prognostic information beyond traditional models. Emerging disease-modifying therapies, in particular Mavacamten, may also influence future risk assessment. However, whether these improvements translate into a true reduction in SCD risk remains uncertain. Importantly, the decision to implant an ICD should not depend on numerical risk alone. It should arise from a process of shared decision-making integrating estimated risk, treatment burden, competing comorbidities, age, lifestyle, and patient values. In this context, the concept of an individualized threshold of “acceptable risk” becomes central. In conclusion, prevention of SCD in HCM is moving beyond conventional scores toward a personalized and dynamic framework in which predictive tools, advanced phenotyping, evolving therapies, clinical expertise, and patient preferences are combined to guide individualized care. Full article

Background/Objectives: Titin (TTN; OMIM 188840) is the largest known human sarcomeric protein, and pathogenic variants in the TTN gene cause a broad spectrum of inherited myopathies and cardiomyopathies. The extent to which TTN variants may also involve the peripheral nervous system remains poorly defined. We aimed to describe two pediatric patients carrying heterozygous truncating TTN variants with neurophysiological evidence of peripheral nerve involvement, and to review the existing literature on this underrecognized association. Pathogenic variants in the TTN gene are associated with a wide spectrum of inherited myopathies and cardiomyopathies. To date, peripheral neur opathy has not been recognized as a defining feature of TTN-related disorders, and neurophysiological investigations in affected individuals typically demonstrate normal or myopathic findings without evidence of a primary neuropathic process. Here, we report two pediatric patients with heterozygous truncating TTN variants and neurophysiological evidence of bilateral axonal involvement of the deep peroneal nerve. Methods: This case report was structured and reported according to the CARE guidelines. Genetic testing was performed using whole-exome sequencing (Blueprint Genetics Whole Exome Family Test). Nerve conduction studies and needle electromyography were performed using the Galileo NT system. Variant classification followed current ACMG guidelines. Results: The first patient, a 10-year-old girl, presented with a symptomatic distal motor phenotype characterized by bilateral pes cavus, anterior compartment muscle atrophy, areflexia, and steppage gait with onset in early childhood. The second patient, an 8-year-old boy, had subclinical bilateral axonal neuropathy identified during neurophysiological evaluation prompted by intermittent lower limb pain; his father, carrying the same variant, showed concordant neurophysiological abnormalities. In both cases, nerve conduction studies demonstrated reduced compound muscle action potential amplitudes with preserved conduction velocities and distal latencies, consistent with axonal neuropathy. Whole-exome sequencing excluded other established genetic causes of inherited neuropathy in both probands. Conclusions: Although a causal relationship cannot be established, these observations raise the possibility that peripheral nerve involvement may represent an underrecognized feature of the titinopathy spectrum. Prospective studies in larger cohorts of TTN variant carriers are needed to clarify the prevalence and pathophysiological basis of neuropathy in this context. Full article

Emery–Dreifuss muscular dystrophy (EDMD) is a rare inherited neuromuscular disorder within the spectrum of nuclear envelope diseases, classically characterized by early musculo-tendinous contractures, slowly progressive myopathy, and cardiac involvement dominated by conduction disease and arrhythmias, with variable evolution toward cardiomyopathy and heart failure. This narrative review provides a comprehensive and clinically actionable synthesis of cardiovascular manifestations across EDMD genotypes and phenotypes, outlining pragmatic diagnostic and therapeutic pathways for real-world care. A targeted literature search was performed in PubMed, Embase, and Web of Science, focusing on studies addressing cardiovascular involvement in EDMD. Relevant original studies, case series, registries, guideline documents, and high-quality reviews were selected and synthesized narratively, with particular emphasis on diagnostic strategies, risk stratification, and management approaches. Cardiac involvement in EDMD encompasses a broad and heterogeneous spectrum, including atrial disease and conduction disturbances, ventricular arrhythmias, dilated cardiomyopathy, thromboembolic complications, and sudden cardiac death. Phenotypic expression varies according to the underlying genetic substrate, with distinct atrial- and ventricular-dominant trajectories. Early recognition and structured cardiovascular surveillance are essential to guide timely intervention, including anticoagulation, device therapy, and heart failure management. Despite growing awareness, significant gaps remain in risk prediction and standardized management strategies. EDMD represents a paradigmatic model of cardiomyopathy characterized by prominent electrical instability and systemic involvement. A structured, genotype- and phenotype-informed approach centered on early surveillance, proactive arrhythmia and thromboembolic risk management and timely device therapy may improve clinical decision-making in real-world settings. Future perspectives include the integration of precision medicine and the development of gene- and pathway-targeted therapies, with the potential to shift from symptomatic management toward disease-modifying strategies. Full article

Background: RASopathies represent a clinically and genetically diverse group of syndromes resulting from germline mutations in genes regulating the RAS/mitogen-activated protein kinase (MAPK) signaling cascade. Methods: The aim of this study was to describe the clinical features and genetic variants identified in patients with genetically confirmed Noonan syndrome (NS) in a limited cohort from Romania. A total of 25 patients with positive genetic testing for NS-associated genes were included. Genetic testing was performed primarily using next-generation sequencing. Results: A total of twenty-six variants were identified in twenty-five patients, as one patient carried two pathogenic variants in the PTPN11 gene (c.188A>G and c.922A>G). Of these variants, twenty-four (92.31%) were classified as pathogenic and two (7.69%) as variants of uncertain significance (VUS). Pathogenic variants were found in different genes, including PTPN11, LZTR1, SOS1, and RAF1, with PTPN11 being the most frequently affected gene. Males predominated (17/25), with a male-to-female ratio of approximately 2:1. Two patients inherited the pathogenic variant from an affected parent. Cardiovascular involvement was present in 21 patients (84%), with pulmonary valve stenosis (PVS) being the most common finding (48%), followed by hypertrophic cardiomyopathy (16%). Additional cardiac anomalies included atrial septal defect, valvular regurgitation, dysplastic valves, coarctation of the aorta, and sinotubular junction narrowing. Short stature was observed in 64% of patients, and craniofacial dysmorphism was present in 96%. Cutaneous, ectodermal, dental, ophthalmologic, and auditory manifestations were variably observed. Conclusions: Although based on a limited cohort from Romania, this study provides insights into clinical features suggestive of NS. Our findings highlight the genetic heterogeneity of NS and emphasize the importance of comprehensive genetic testing for confirming diagnosis, guiding clinical management, and supporting family counseling. Full article

Background/Objectives: Infantile cardiomyopathy is a rare but often life-threatening condition in which monogenic causes are particularly relevant, especially when cardiac disease is preceded by hypotonia or multisystem involvement. Among sarcomeric genes, MYL2, encoding the ventricular regulatory myosin light chain, plays a critical role in myocardial contractility. However, biallelic MYL2-associated disease remains exceptionally rare, and its clinical spectrum is not fully defined. This study aims to describe a novel case and further delineate the phenotype of recessive MYL2-related cardiomyopathy. Methods: We report a male infant with congenital hypotonia and delayed motor development who underwent extensive metabolic, neuromuscular, and neuroimaging evaluation. Trio-based whole-exome sequencing was performed to identify a potential genetic etiology, followed by variant interpretation using standard bioinformatic and ACMG/AMP criteria. Results: The patient developed acute decompensated heart failure at approximately 10 months of age, with severe left ventricular systolic dysfunction and multiorgan failure, and died at 12 months despite maximal intensive care support. Whole-exome sequencing identified a homozygous MYL2 c.413T>A (p.Met138Lys) missense variant. The variant is absent or extremely rare in population databases, affects a highly conserved residue, is predicted to be deleterious by multiple in silico tools, and is compatible with autosomal recessive inheritance, with both parents confirmed as heterozygous carriers. In the context of a phenotype consistent with recessive MYL2-associated disease, these findings support a likely pathogenic interpretation. Conclusions: This case expands the allelic and phenotypic spectrum of recessive MYL2-associated cardiomyopathy and highlights the value of early genomic testing in infants with unexplained hypotonia and rapidly progressive cardiac dysfunction. Molecular diagnosis may aid in prognosis, clinical decision-making, and genetic counseling. Full article

Background: Arrhythmogenic cardiomyopathy (ACM) is an inherited disorder characterized by fibrofatty replacement of cardiomyocytes. The inflammatory episodes of ACM, known as the “hot phase”, can mimic acute myocarditis. It was seldom observed in a DES-associated ACM as a “hot-phase” presentation. Case Presentation: The proband, a 13-year-old female, initially presented with a series of clinical manifestations of fulminant myocarditis. Although recommendation-guided anti-immunotherapy had been provided, this patient still developed into an aggressive cardiomyopathy with biventricular dilation and severe systolic heart failure. Additionally, cardiac magnetic resonance demonstrated circumferential late gadolinium enhancement in left ventricular myocardium with diffuse fibrosis. Whole-exon sequencing identified a de novo missense variant, as c.335T>A (p.L112Q) of the DES gene, resulting in protein dysfunction. And a diagnosis of ACM due to a DES variant had been identified. Finally, this patient received heart transplantation, and biventricular fibrofatty infiltration was confirmed by pathological analysis. Conclusions: This case presented a de novo genetic variant that can induce severe and aggressive heart failure. This finding emphasizes the importance of comprehensive genetic analysis in patients suspected of having fulminant myocarditis, which would greatly benefit the precise clinical management and outcomes. Full article

Inherited cardiomyopathies associated with high-risk genotypes, are characterized by a disproportionate risk of malignant ventricular arrhythmias and sudden cardiac death, often independent of left ventricular systolic dysfunction or advanced structural remodeling. Traditional surveillance strategies based on intermittent electrocardiography and phenotype-driven risk assessment are insufficient to capture the dynamic and often silent progression of electrical instability in these populations. This narrative review evaluates the emerging role of artificial intelligence (AI)-enabled sensor technologies in remote arrhythmic monitoring of genetically defined cardiomyopathy cohorts. Wearable ECG devices, implantable cardiac monitors, multisensor cardiac implantable electronic device algorithms, pulmonary artery pressure sensors, and contact-free systems enable continuous acquisition of electrophysiological and hemodynamic data, generating digital biomarkers that may reflect early arrhythmic vulnerability and subclinical decompensation. AI-driven analytics enhance signal processing, automated event detection, and remote data triage, with the potential to reduce clinical workload while preserving diagnostic sensitivity. However, current evidence predominantly derives from heterogeneous heart failure or general arrhythmia populations, and prospective validation in genotype-specific cohorts remains limited. Key challenges include algorithm generalizability, signal quality in ambulatory environments, data governance, interpretability of AI models, and integration into structured remote-care pathways. The convergence of genotype-informed risk stratification and multimodal AI-enabled sensing represents a promising strategy to transition from reactive device-based protection to proactive, precision-guided arrhythmic prevention. Dedicated genotype-focused studies and standardized digital endpoints are required to support safe and effective implementation in inherited cardiomyopathies. Full article