Search Results (323)

Introduction: Cardiomyopathies (DCM, HCM, and ACM) and primary arrhythmogenic disorders (BrS, LQTS, and CPVT) represent the most common causes of sudden cardiac death (SCD) in young individuals. Systematic genome-wide single-nucleotide polymorphism (SNP) analyses and genome-wide association studies (GWASs) have enabled the identification of numerous genetic variants associated with cardiovascular diseases. Body: Genetic testing for cardiomyopathies and inherited channelopathies primarily involves panel testing of genes with definitive and strong evidence of disease association; genes supported by moderate evidence may also be considered. Cardiomyocytes express a variety of proteins implicated in the pathogenesis of genetic cardiomyopathies, including sarcomeric, cytoskeletal, desmosomal, and nuclear envelope proteins. Inherited cardiac channelopathies result from mutations in genes encoding cellular components that influence calcium ion availability or affect membrane ion channels, including sodium, potassium, and calcium channels. Common variants associated with SCD are found in genes encoding cardiac ion channels (e.g., SCN5A, KCNQ1, and KCNH2), calmodulin (CALM2), sarcomeric proteins (MYH7, MYBPC3, TTN, and TNNI3), and desmosomal proteins (RyR2 and DES). Conclusions: This review demonstrates that specific genetic variants are significantly associated with an increased risk of SCD. The evidence underscores the importance of genetic screening and early intervention in individuals with a family history of SCD or other risk factors for inherited cardiac disorders predisposing to SCD. Future research should focus on gene-specific management strategies for familial cardiomyopathies and inherited channelopathies, with the goal of improving targeted genetic therapies and reducing the burden of sudden cardiac death. Full article

Hypertrophic cardiomyopathies (HCMs) are among the most common genetic disorders; however, they might be underdiagnosed. Sequencing core sarcomere gene panels remain the main diagnostic tool. We present the results of HCM genetic testing performed at Lithuania’s tertiary care center. All patients with diagnosed or clinically suspected HCM underwent next-generation panel sequencing. Of 204 patients, 34 (16.7%) received a genetic diagnosis. The most commonly affected genes were MYBPC3 and MYH7. Notably, two patients were found to have LEOPARD syndrome due to PTPN11 gene variants. Our results indicate that patients with an identified pathogenic variant were diagnosed with HCM at a younger age and exhibited a more severe phenotype (greater septal wall thickness), although no clear correlation with family history was observed. In addition, four novel MYBPC3 variants, c.3467dup, c.1503C>G, c.2610dup, and c.1251del, were identified. Full article

Hypertrophic cardiomyopathy (HCM) is a common and deadly cardiac disease characterized by enlarged myocytes, increased myocardial wall thickening, and fibrosis. A majority of HCM cases are associated with mutations in the β-myosin heavy chain (MYH7) converter domain locus, which leads to varied pathophysiological and clinical manifestations. Using base-editing technology, we generated mutant human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) harboring HCM-causing myosin converter domain mutations (MYH7 c.2167C>T [R723C]; MYH6 c.2173C>T [R725C]) to define HCM pathogenesis in vitro. In this study, we integrated transcriptomic analysis with phenotypic and molecular analyses to dissect the HCM disease mechanisms using MYH6/7 myosin mutants. Our KEGG analysis of bulk RNA-sequencing data revealed significant upregulation of transcripts associated with HCM in the mutant hiPSC-CMs. Further, in-depth transcriptomic analysis using Gene-Ontology (GO-term) analysis for biological process showed upregulation of several transcripts associated with heart development and disease. Notably, our analysis showed robust upregulation of cytoskeletal transcripts, including actin-cytoskeleton networks, sarcomere components, and other structural proteins in the mutant CMs. Furthermore, cellular and nuclear morphological analysis showed that the MYH6/7 mutation induced cellular hypertrophy and increased aspect ratio compared to the isogenic control. Immunostaining experiments showed marked sarcomere disorganization with lower sarcomeric order and higher dispersion in the mutant hiPSC-CMs, highlighting the remodeling of the myofibril arrangement. Notably, the MYH6/7 mutant showed reduced cortical F-actin expression and increased central F-actin expression compared to the isogenic control, confirming the cytoskeletal remodeling and sarcomeric organization during HCM pathogenesis. These pathological changes accumulated progressively over time, underscoring the chronic and evolving nature of HCM driven by the MYH6/7 mutations. Together, our findings provide critical insights into the cellular and molecular underpinnings of MYH6/7-mutation-associated disease. These findings offer valuable insights into HCM pathogenesis, aiding in future therapies. Full article

Hypertrophic cardiomyopathy (HCM) progressing to end-stage heart failure and heart transplantation (HT) is a rare clinical scenario with an insufficiently explored genetic background. In this single-center retrospective cohort study, we aimed to characterize the genetic spectrum, variants of HCM adverse remodeling, and aspects of molecular pathogenesis of this subgroup. The study included 14 patients (9 females), among whom 10 developed a dilated/hypokinetic phenotype and 4 a restrictive phenotype. In 13 patients (93%), at least one pathogenic or likely pathogenic genetic variant was identified. Dilated remodeling/hypokinesis was associated with loss-of-function variants in LAMP2 (3) in females, ALPK3homo (1), MYH7 (1), MYBPC3 (1), a heterozygous missense variant in TRIM63 (1), FLNCtv (1), TTNtv (2). For the latter two, electrophoretic analysis of titin isoform composition and protein content in myocardial fragments from explanted hearts confirmed the functional significance of TTN gene variants. The restrictive phenotype in the adult group was associated with carriage of multiple pathogenic sarcomere gene variants: MYL3homo (1), MYBPC3+TPM1 (1), an MYH7 converter domain variant (1), and, in one child, with a TNNT2 variant. This findings support HCM progressing to HT is characterized by a higher frequency of variants in non-sarcomeric genes and Danon disease compared to the general HCM cohort. Full article

Sujiang pigs, a high-quality local Chinese breed, represent a valuable model for investigating muscle development and improving meat production through genetic selection. Skeletal muscle satellite cells (MuSCs) are essential regulators of muscle growth, with differentiation tightly controlled by specific genes and signaling pathways. In this study, MuSCs were isolated from the gastrocnemius muscle and subjected to mRNA sequencing during proliferation (GM) and differentiation stages (DM1, DM2, and DM4, collectively referred to as DM). A total of 2790 differentially expressed genes (DEGs) were identified, including 1551 upregulated and 1239 downregulated genes. Time-series analysis revealed 16 significant expression patterns. These DEGs were primarily associated with muscle development and differentiation and were enriched in Wnt, PI3K–Akt, JAK–STAT, p53, Hippo, and Apelin signaling pathways. Among them, phosphoribosyl transferase domain containing 1 (PRTFDC1) exhibited pronounced downregulation during differentiation. Functional validation demonstrated that PRTFDC1 overexpression promoted myotube formation and upregulated MYOD1, MYOG, and MYH1 expression, whereas knockdown significantly inhibited differentiation. Furthermore, PRTFDC1 enhanced phosphorylation of key proteins in the cGAS–STING signaling pathway. Collectively, this study elucidates the temporal transcriptional regulation of MuSC differentiation in Sujiang pigs and identifies PRTFDC1 as a novel regulatory factor, providing a molecular foundation for breeding strategies and meat quality improvement. Full article

This study investigated meat quality, nutritional characteristics, and transcriptomic regulation in Yunan (YN) black pigs and Huainan (HN) black pigs (n = 6 each). Analysis of fatty acid composition revealed that HN black pigs possessed significantly higher levels of most fatty acids compared to YN black pigs. Notably, the contents of monounsaturated fatty acid C18:1n9c and polyunsaturated fatty acid C18:2n6c in HN black pigs were 1.94-fold and 2.65-fold higher, respectively, than those in YN black pigs. The α-linolenic acid content was also significantly elevated in HN black pigs, indicating an overall higher fatty acid content. Regarding amino acid differences, HN black pigs exhibited significantly higher levels of aspartic acid, glutamic acid, histidine, as well as superior composition of total amino acids, total umami amino acids, and essential amino acids, which contribute to enhanced flavor characteristics and nutritional balance. Transcriptome analysis identified 526 differentially expressed genes in HN vs. YN. KEGG enrichment analysis showed that these genes were involved in many adipogenesis and lipid metabolism signaling pathways, such as biosynthesis of unsaturated fatty acids, fatty acid elongation, apelin signaling pathway and lysine degradation. By integrating transcriptome and protein–protein interaction (PPI) network analyses, we identified key meat quality-related genes: ELOVL6, PRKAG3, ROCK2, and MYH11. miRNA profiling identified ssc-miR-133b, ssc-miR-206, and miR-205 as key regulators of meat quality. This study provides a valuable theoretical foundation for understanding the molecular mechanisms underlying pork quality and offers insights for its future improvement. Full article

Inherited arrhythmias and cardiomyopathies are a group of potentially lethal genetic cardiac disorders which are often passed down through generations and pose risks to several family members. While individually rare, these conditions are collectively common and pose significant challenges for clinical management given their variable severity, age of onset, and response to treatments. Earlier genetic analyses revealed crucial insights into the main genetic culprits of these disorders, such as SCN5A for Brugada syndrome, and MYH7 and MYBPC3 for hypertrophic cardiomyopathy, which have revolutionized diagnosis, risk stratification, and medical management. Nonetheless, issues such as variable expressivity and penetrance, low yield of genetic testing, and relative lack of disease-modifying therapies remain significant hurdles for clinical management. The revolution of genome-wide association studies GWASs has transformed our understanding of inherited arrhythmias and cardiomyopathies, shifting the view of these disorders from a monogenic Mendelian inheritance towards a more complex, often polygenic inheritance with nuanced interplay between genetics and environment. Moreover, GWASs have enabled the quantification of polygenic predisposition to disease using polygenic risk scores, which are often complementary to and independent of monogenic risk. In this review, we highlight how GWASs have transformed the field of inherited arrhythmias and cardiomyopathies, with a particular focus on the polygenic risk scores developed and their clinical utility for the four disorders which have been impacted by GWASs—hypertrophic cardiomyopathy, dilated cardiomyopathy, Brugada syndrome, and long QT syndrome. Full article

Background: Dilated cardiomyopathy (DCM) is a myocardial disorder characterized by structural and functional abnormalities, in particular left or biventricular chamber dilatation and systolic dysfunction, occurring without evidence of coronary artery disease, hypertension, valvular disease, or congenital heart defects. It is a significant cause of sudden cardiac death, particularly in young individuals, often remaining undiagnosed until autopsy. Methods: A systematic review of the literature was conducted following PRISMA guidelines to revisit the main postmortem findings (gross, microscopic, and genetic) useful to perform the postmortem diagnosis of DCM. Scientific databases (PubMed and Scopus) were searched for articles published up to February 2025 describing postmortem findings in individuals diagnosed with DCM. Inclusion criteria were focused on studies reporting macroscopic cardiac findings, and microscopic and genetic variants identified postmortem or in related familial studies. Data were extracted and categorized to identify consistent diagnostic markers and to assess the frequency and relevance of genetic findings in autopsy-confirmed DCM cases. From 2081 initial records, 30 studies met inclusion criteria. Two reviewers independently performed study selection and data extraction, and methodological limitations of the included studies were considered qualitatively to inform the synthesis. Results: Common macroscopic features included increased heart weight (often > 350 g), dilated left or biventricular chambers, and thinning of the ventricular walls. Histologically, the most consistent findings were diffuse interstitial fibrosis, myocyte hypertrophy, and nuclear atypia. Particular attention was given to morphological features essential to distinguish between genetic and nongenetic forms of DCM and, thus, useful to perform a differential diagnosis with disease having a DCM-like pattern. Notably, truncating variants in genes such as TTN, FLNC, DSP, PKP2, and MYH7 were frequently reported, particularly in young decedents with no significant history of cardiac disease. However, only about half of reviewed studies included any form of genetic analysis, reflecting a significant gap in current practice for forensic pathologists. Conclusions: DCM may cause sudden death without prior symptoms, making genetic testing essential to uncover the diagnosis, especially in cases with a negative phenotype. Therefore, molecular autopsy combined with careful macroscopic and microscopic analysis can strengthen the forensic assessment. Full article

This study examines pediatric cardiomyopathies by analyzing genetic and clinical data from 55 patients (2021–2024) at Beijing Anzhen Hospital. Four subtypes were studied: dilated (DCM, 24), hypertrophic (HCM, 22), arrhythmogenic right ventricular (ARVC, 7), and restrictive (RCM, 2). Clinical data, imaging, labs, and family histories were collected, with whole-exome sequencing (WES) identifying disease-causing variants classified via ACMG guidelines. Statistical analysis revealed a median age of 11 years, a proportion of 58% male participants, and ethnic diversity (21 northern Han, 29 southern Han, 5 minorities). In the cohort, 13 cases had an LVEF below 35%. Pathogenic/likely pathogenic (P/LP) variants were found in 21.8% of the patients, and variants of uncertain significance (VUS) were present in 38.2%, with MYH7 (seven cases) and MYBPC3 (five) being the most common. The WES positivity rates varied, at 58.3% (DCM), 72.7% (HCM), and 33.3% (ARVC/RCM). DCM patients with P/LP/VUS variants showed better contractile function (Fractional Shortening: 29.0% vs. 16.5%, p = 0.008). Females in the DCM group had poorer cardiac function (lower LVEF, higher LVESd, lower cardiac output) compared to males, with more females (nine vs. three) exhibiting an LVEF < 35% (p = 0.041). No significant gender differences were observed in the HCM cases. These findings highlight genotype–phenotype correlations and underscore the need for early intervention in female DCM patients. Full article

Intramuscular fat (IMF) refers to the adipose tissue located between muscle fibers and is a major determinant of meat quality in cattle. The cellular origin of bovine intramuscular adipocytes remains unclear. Therefore, the objective of this study was to investigate this origin. We derived single-preadipocyte clones from IMF and subcutaneous fat (SF) of cattle through single-cell cloning and subsequent validation of their potential to differentiate into adipocytes. Transcriptomic analysis of selected single-preadipocyte clones revealed that although both IMF- and SF-derived preadipocyte clones expressed classical preadipocyte markers such as PDGFRA, DLK1, and ZNF423, they differed significantly in global gene expression profile. Notably, many muscle-specific genes (e.g., MYOG, MB, and MYH3) were expressed at high levels in IMF-derived preadipocyte clones while not expressed in SF-derived clones. Functional enrichment analysis of differentially expressed genes between IMF- and SF-derived preadipocyte clones indicated that many muscle-related functions were enriched in the former. Furthermore, high-level expression of muscle-specific genes persisted in mature adipocytes differentiated from IMF-derived preadipocyte clones. We also found that bovine satellite cells, the widely considered progenitor cells of myocytes in postnatal animals, had the ability to form both myocytes and adipocytes under respective differentiation conditions. Based on these findings, we conclude that in cattle, at least some intramuscular adipocytes are derived from satellite cells. Full article

The transcriptional regulation of MYH6 and MYH7 genes has been extensively investigated in healthy versus failing hearts; however, their expression dynamics in healthy human hearts across age and sex, particularly in the context of cardiovascular risk factors such as hypertension, remain poorly characterised. This study aimed to carry out a reanalysis of MYH6 and MYH7 transcript levels in a large cohort of non-failing human left ventricular samples, stratified by sex, age, and hypertensive status. Furthermore, we examined how age and sex influence gene expression differences between non-failing and failing hearts, the latter affected by dilated cardiomyopathy (DCM). Normalised expression values for MYH6 and MYH7 transcripts from both healthy and failing left ventricles were extracted using the GEO2R online analysis tool from the publicly available RNA-sequencing library GSE141910. This library provides transcriptomic profiles of left ventricular (LV) tissue from both healthy individuals and patients with cardiomyopathies. The Mann–Whitney U test was employed for pairwise comparisons between different groups stratified by sex, age, and hypertensive status. Statistical analysis demonstrates sex-specific differences in MYH6 and MYH7 expression in healthy left ventricles, with postmenopausal females (aged > 50 years) with hypertension emerging as a distinct group. Conversely, in end-stage DCM hearts, the expression levels of both myosin genes seemed to be primarily influenced by disease-related pathophysiological mechanisms rather than by sex or age. Comparison between healthy and failing hearts revealed a consistent and significant downregulation of MYH6 in all comparisons, irrespective of sex or age. On the other hand, MYH7 expression exhibited greater variability, particularly among males, with age and hypertensive status influencing its expression. The results underscore the importance of considering age, sex, and comorbidities in interpreting cardiac gene expression patterns and highlight potential regulatory divergence in contractile gene expression during cardiac remodelling. Full article

Background: MYH9-related disease (MYH9-RD) is the most common form of inherited thrombocytopenia (IT). It is caused by pathogenic variants in the MYH9 gene. It manifests as early-onset macrothrombocytopenia with variable later-onset extra-hematological features, including hearing loss, renal disease, and cataracts. In pediatric patients, early recognition is critical to avoid misdiagnosis as immune thrombocytopenia (ITP) and unnecessary immunosuppressive therapy. Methods: We conducted a retrospective unicentric study at the Pediatric Oncology and Hematology Department, Fundeni Clinical Institute, Bucharest, Romania, including patients aged 0–18 years with suspected IT, tested between 2017 and 2025 by next-generation sequencing (NGS). Clinical, laboratory, and genetic data were reviewed. Results: Among 66 patients who underwent genetic testing, 31 (48.5%) had IT-associated genetic variants; 8 (25.8%) carried MYH9 mutations. Four patients (50%) had disease onset before age 1 year, three with neonatal presentation; 3 (37.5%) reported a family history of thrombocytopenia. Six variants were previously reported, and two were novel variants. Five variants (62.5%) were pathogenic, while three (37.5%) were initially classified as variants of uncertain significance (VUS). Most mutations were missense in the coiled-coil tail domain, correlating with milder thrombocytopenia and absence of extra-hematological features. No life-threatening bleeding was recorded; hemorrhagic symptoms were limited to minor mucocutaneous bleeding. Conclusions: This is the first Romanian pediatric cohort and one of the few existing pediatric cohorts describing the genetic and clinical spectrum of MYH9-RD. Early genetic confirmation enables precise diagnosis, tailored management, and family screening, while preventing inappropriate therapies. Full article

Background: Pediatric acute myeloid leukemia (pAML) is the second most common type of childhood leukemia, behind acute lymphoblastic leukemia. High-throughput technologies have enabled the identification of increasing molecular alterations linked to AML prognosis, revealing genomic heterogeneity among individual patients and providing clinically valuable diagnostic and prognostic information. This study systematically analyzed the correlation between high-frequency mutated genes and prognosis in pAML by performing whole-transcriptome sequencing (WTS) of bone marrow samples from newly diagnosed AML children in Southwest China and mapping their genetic profiles. Methods: pAML patients treated at the Department of Hematology and Oncology, Children’s Hospital of Chongqing Medical University, from January 2015 to October 2024, were enrolled, and WTS was performed. The study described the frequency, pathogenicity classification, and risk stratification of mutation genes and fusion genes, and constructed a genetic landscape. For high-frequency pAML mutations, the impact on early induction remission rate (CR) and long-term event-free survival (EFS) was evaluated. Results: A total of 134 pediatric AML patients from Southwest China were included, with a male-to-female ratio of 74:60 and a median diagnosis age of 5.96 years. Based on pathogenicity classification using WTS, fusion genes were categorized into level 1, level 2, and level 3 genes, as well as mutation genes. The study identified five fusion genes of level 1, the most frequent being RUNX1::RUNX1T1 (32/134, 23.88%), KMT2A rearrangements (29/134, 21.64%), and CBFB::MYH11 (13/134, 9.7%). Sixteen mutation genes of level 1 were detected, seven of which recurred in over 5% of patients, including NRAS (31/134, 23.13%), FLT3 (25/134, 18.66%), KIT (24/134, 17.91%), CEBPA (14/134, 10.45%), WT1 (13/134, 9.7%), KRAS (11/134, 8.2%), and PTPN11 (7/134, 5.22%). Sex-based analysis revealed that PTPN11 mutations were significantly more frequent in males (9.45% vs. 0%, p = 0.023), as were KIT mutations (24.32% vs. 10.00%, p = 0.044). Risk-stratified analysis showed that WT1 mutations (14.13% vs. 0%, p = 0.031) and FLT3-ITD mutations (13.19% vs. 0%, p = 0.042) were enriched in intermediate- and high-risk groups, whereas CEBPA (25.64% vs. 5.43%, p = 0.012), KIT (35.90% vs. 10.87%, p = 0.003), and KIT-E8 (20.51% vs. 1.10%, p < 0.001) mutations were more prevalent in low-risk groups. Prognostic analysis indicated that PTPN11 and KIT mutations did not affect CR or EFS across sexes, nor did WT1, CEBPA, or KIT mutations influence outcomes by risk stratification. However, FLT3-ITD-positive patients had significantly lower CRs (χ² value = 11.965, p = 0.007), although EFS differences were nonsignificant. In contrast, WT1 mutations were associated with inferior EFS compared to wild-type (p = 0.036). Furthermore, the univariate and multivariate Cox regression revealed consistent results with the above findings, indicating that WT1 mutation was an independent adverse prognostic factor for EFS (HR = 2.400, 95% CI: 1.101–5.233, p = 0.028). The results of univariate and multivariate logistic regression analyses also confirmed that FLT3-ITD mutation was an independent predictor of initial treatment response in our cohort (OR = 10.699, 95% CI: 2.108–54.302, p = 0.004). Conclusions: This study delineated the genetic landscape of pAML in Southwest China and explored the prognostic value of gene fusions and mutations in early and long-term outcomes. These findings provide a foundation for understanding the genetic heterogeneity of pAML and offer evidence for the development of precision medicine approaches. Full article

We report a unique pediatric acute myeloid leukemia (AML) case characterized by a CBFB::MYH11 fusion located on a supernumerary ring chromosome 16. Following diagnosis through comprehensive blood and bone marrow assays, the patient was enrolled in the Children’s Oncology Group (COG) study AAML1831 and randomized to the experimental treatment arm (Arm B). She received induction chemotherapy with CPX-351 (liposomal daunorubicin and cytarabine), gemtuzumab and ozogamicin (GO), and the cardioprotectant dexrazoxane and achieved complete remission (CR). The patient completed the treatment with sustained CR for 18 months. This case represents a rare cytogenetic phenomenon that is not well-documented in the current literature. Through a review of relevant publications, we contextualize this case within the spectrum of core binding factor AML (CBF-AML), highlighting diagnostic approaches, treatment strategies, and prognostic implications, particularly in cases involving atypical CBFB::MYH11 fusions. The durable remission observed in this patient, despite the unusual cytogenetic presentation, provides valuable insights into therapeutic management. This report underscores the cytogenetic and molecular heterogeneity of CBFB::MYH11 AML and emphasizes the importance of comprehensive genetic profiling using advanced techniques such as chromosomal microarray and next-generation sequencing. Full article

MicroRNAs (miRNAs), small non-coding RNAs, have emerged as promising diagnostic and prognostic biomarkers for various diseases. However, their role in the pathogenesis of type 2 diabetes mellitus (T2DM) remains insufficiently defined. This case–control study investigated associations between genetic variants in miRNA genes and susceptibility to T2DM in a Greek population. A total of 716 individuals with T2DM and 569 controls (HbA1c < 6.5% and fasting plasma glucose < 126 mg/dL) were included. Genomic DNA was extracted from whole blood and genotyped using the Illumina Infinium PsychArray platform. Polymorphisms in MIR124a, MIR27a, MIR146a, MIR34a, MIRLET7A2, MIR128a, MIR196a2, MIR499a, MIR4513, and MIR149 were analyzed, with all SNPs within 20 kb upstream and downstream of each gene assessed. Allele frequencies were compared between cases and controls using PLINK. Significant associations with increased T2DM risk were observed for rs1531212 (OR = 1.375, p = 0.018) in MIR23aHG (containing MIR27a) and rs6120777 (OR = 1.27, p = 0.018) in MYH7B, upstream of MIR499a. Conversely, rs2425012 (OR = 0.794, p = 0.018) upstream of MIR27a, as well as rs883517 (OR = 0.728, p = 0.024) and rs2961920 (OR = 0.80, p = 0.041) upstream of MIR146a, appeared protective. Under the dominant model, two additional associations emerged: rs3746435 (OR = 1.239, p = 0.025) in MYH7B (upstream of MIR499a) and rs3746444 (OR = 1.235, p = 0.046) in MIR499a. In conclusion, this study identifies three novel genetic variants near MIR27a and MIR499a that may influence susceptibility to T2DM. These findings warrant validation in larger cohorts and functional studies to clarify their role in T2DM pathogenesis. Full article