Circulation: Genomic and Precision Medicine最新文献

Background: ACTA2 pathogenic variants predispose to thoracic aortic disease, and a subset of variants lead to early onset atherosclerotic cardiovascular disease (ASCVD). The molecular pathway linking misfolded SMA (α-smooth muscle actin) monomers to augmented atherosclerosis-associated smooth muscle cell phenotypic modulation can be modeled in vitro by stably expressing the ACTA2 p.R149C variant in Acta2^-/- smooth muscle cells.

Methods: The Montalcino Aortic Consortium patient registry was used to identify cases with ACTA2 pathogenic/likely pathogenic missense variants. These patients were surveyed, and their medical records were reviewed to identify cases with early onset ASCVD. The variants for these cases, as well as other recurrent ACTA2 missense variants, were individually expressed in Acta2^-/- smooth muscle cells, and transcript and protein levels, HSF1 (heat shock factor 1) activation, HMGCR (3-hydroxy-3-methylglutaryl-coenzyme A reductase) expression and activity, cholesteryl ester levels, and downstream smooth muscle cell phenotypic modulation were assessed.

Results: Early onset ASCVD included coronary artery disease, peripheral vascular disease, and atherosclerotic plaques identified by imaging in the arch, descending, or abdominal aorta, along with the celiac, iliac, renal, or vertebral arteries. Twelve ACTA2 variants were identified to be associated with early onset ASCVD. Early onset ASCVD was correlated with HSF1 activation (P=0.035), cellular cholesteryl ester levels (P=0.0031), and having one family member with the specific ACTA2 pathogenic variant who had early onset ASCVD (P=0.0001).

Conclusions: Assays assessing the molecular mechanism that leads to early onset ASCVD can identify which ACTA2 pathogenic variants will trigger this condition. Ultimately, this information informs precision medical care for individuals with ACTA2 pathogenic variants, with the ultimate goal of preventing thoracic aortic disease and ASCVD.

Background: The analysis of the circulating proteome can identify translational modifiers and biomarkers of disease expressivity and severity at a given time point. Here, we explore the relationships between protein measures implicated in cardiovascular disease and whether they mediate causal relationships between cardiovascular risk factors and disease development.

Methods: To understand the relationships between circulating biomarkers and genetic variants, medications, anthropometric traits, lifestyle factors, imaging-derived measures, and diagnoses of cardiovascular disease, we undertook in-depth analyses of measures of 9 plasma proteins with a priori roles in genetic and structural cardiovascular disease or treatment pathways (ACE2 [angiotensin-converting enzyme 2], ACTA2 [actin alpha 2], ACTN4 [actinin alpha 4], BAG3 [BAG cochaperone 3], BNP [B-type natriuretic peptide], CDKN1A [cyclin-dependent kinase inhibitor 1A], NOTCH1 [neurogenic locus notch homolog protein 1], NT-proBNP [N-terminal pro-B-type natriuretic peptide], and TNNI3 [troponin I]) from the Pharma Proteomics Project of the UK Biobank cohort (over 45 000 participants sampled at recruitment).

Results: We identified significant variability in circulating proteins with age, sex, ancestry, alcohol intake, smoking, and medication intake. Phenome-wide association studies highlighted the range of cardiovascular clinical features with relationships to protein levels. Genome-wide genetic association studies identified variants near GCKR, APOE, and SERPINA1, that modified multiple circulating protein levels (BAG3, CDKN1A, and NOTCH1). NT-proBNP and BNP levels associated with variants in BAG3. ACE2 levels were increased with a diagnosis of hypertension or diabetes, particularly in females, and were influenced by variants in genes associated with diabetes (HNF1A and HNF4A). Two-sample Mendelian randomization identified ACE2 as protective for systolic blood pressure and type-2 diabetes.

Conclusions: From a panel of circulating proteins, the results from this observational study provide evidence that ACE2 is causally protective for hypertension and diabetes. This suggests that ACE2 treatment may provide additional protection from these cardiovascular diseases. This study provides an improved understanding of the circulating pathways depicting cardiovascular disease dynamics.

Background: Congenital long-QT syndrome is most often associated with pathogenic variants in KCNQ1 encoding the pore-forming voltage-gated potassium channel subunit (KCNQ1) of the slow delayed rectifier current (I_Ks). Generation of I_Ks requires assembly of KCNQ1 with an auxiliary subunit (KCNE1) encoded by KCNE1, which is also associated with long-QT syndrome, but the causality of autosomal dominant disease is disputed. By contrast, KCNE1 is an accepted cause of recessive Jervell and Lange-Nielson syndrome type 2 (JLN2). The functional consequences of most KCNE1 variants have not been determined, and the population prevalence of JLN2 is unknown.

Methods: We determined the functional properties of 95 KCNE1 variants coexpressed with KCNQ1 in heterologous cells using high-throughput voltage-clamp recording. Experiments were conducted with each KCNE1 variant expressed in the homozygous state, and then a subset was studied in the heterozygous state. The carrier frequency of JLN2 was estimated by considering the population prevalence of dysfunctional variants.

Results: There is substantial overlap between disease-associated and population KCNE1 variants. When examined in the homozygous state, 68 KCNE1 variants exhibited significant differences in at least 1 functional property compared with wild-type KCNE1, whereas 27 variants did not significantly affect function. Most dysfunctional variants exhibited loss-of-function properties. We observed no apparent dominant-negative effects when variant and wild-type KCNE1 were coexpressed. Most variants were scored as variants of uncertain significance, and inclusion of functional data resulted in revised classifications for 14 variants. The population carrier frequency of JLN2 was calculated as 1 in 1034. Peak current density and activation voltage-dependence, but not other biophysical properties, were correlated with findings from a mutational scan of KCNE1.

Conclusions: Among 95 disease-associated or population KCNE1 variants, many exhibit abnormal functional properties without apparent dominant-negative behaviors. Using functional data, we inferred a population carrier frequency for recessive JLN2. This work helps clarify the pathogenicity of KCNE1 variants.

Background: Desmin is a muscle-specific intermediate filament protein crucial for maintaining cardiomyocyte structural integrity, connecting multiprotein complexes and organelles. Although DES mutations are known to cause various (cardio)myopathies, many rare variants remain classified as variants of uncertain significance.

Methods: We generated expression plasmids for 93 variants of uncertain significance located in the 1B domain and assessed filament formation in multiple cell lines, including cardiomyocytes derived from induced pluripotent stem cells. Filament assembly of purified wild-type and mutant desmin was analyzed using atomic force microscopy. Sequencing of 399 patients with severe dilated cardiomyopathy identified the DES-p.L187P variant in 1 individual. Desmin localization in explanted myocardial tissue from this patient was examined via immunohistochemistry.

Results: Four variants (p.L159P, p.R163P, p.L187P, and p.E197del) caused filament formation defects, disrupting assembly even when coexpressed with wild-type desmin-consistent with dominant inheritance. Atomic force microscopy revealed that these mutations impaired filament formation, resulting in small desmin complexes, while wild-type desmin formed regular filaments. Systematic proline substitutions across the 1B domain showed that insertions at hydrophobic a- and d-sites disrupted filament assembly, whereas others had minimal impact. Immunohistochemistry confirmed desmin disorganization in myocardial tissue from a DES-p.L187P mutation carrier with dilated cardiomyopathy.

Conclusions: The atlas of cardiomyopathy-associated desmin mutations represents a significant step toward improving the clinical interpretation of DES variants associated with cardiomyopathies. Our data provide robust evidence that 4 variants of previously unknown significance listed in the ClinVar database warrant reclassification as likely pathogenic mutations based on their molecular effects. Specifically, we demonstrated that proline insertions-particularly at positions where hydrophobic amino acids contribute to the intermolecular interactions between alpha helices-lead to desmin filament assembly defects. These findings not only enhance our understanding of desmin-related cardiomyopathies but also offer a valuable resource for cardiologists and genetic counselors in guiding diagnosis, risk stratification, and patient counseling.

Pathogenic variants in ALPK3 (α-protein kinase 3), an atypical α‑kinase acting as a sarcomeric M-band scaffold, cause cardiomyopathy with severity linked to zygosity. We present a comprehensive review with systematic curation of peer-reviewed clinical and experimental reports through June 9, 2025, encompassing 156 patient-level variants and all published preclinical models. Biallelic loss-of-function variants lead to severe, often lethal cardiomyopathy with prenatal or early onset presentation and extracardiac involvement. Heterozygous protein-truncating variants, defined as nonsense or frameshift (resulting from insertion/deletion events or splicing mutations), explain ≈1% to 4% of adult hypertrophic cardiomyopathy, often with apical/septal hypertrophy, right ventricular involvement, fibrosis, and risk of progression. ALPK3 lacks catalytic activity and maintains sarcomeric proteostasis by scaffolding MYOMs (myomesins), MuRF (muscle ring-finger protein) E3 ligases, and SQSTM1 (sequestosome-1)/p62. Loss of this scaffolding function displaces MYOMs, drives thick‑filament protein aggregation, and precipitates severe contractile dysfunction in human induced pluripotent stem cell-derived cardiomyocytes and multiple mouse models. Therapeutic proof‑of‑concept has now been achieved on 2 fronts: (1) pharmacological correction of sarcomeric hypercontractility with the myosin inhibitor mavacamten and (2) durable phenotypic rescue in global knockout mice using an adeno-associated virus-delivered miniALPK3 gene‑replacement construct. Together, these data position ALPK3 cardiomyopathy as a compelling target for precision medicine. Early genetic diagnosis, genotype-tailored surveillance, and focused development of gene-replacement or editing strategies, potentially combined with modulators of the ALPK3-MuRF proteostatic axis, offer a realistic path to disease-modifying therapy for this once enigmatic condition.

Background: Hypertrophic cardiomyopathy (HCM) is a relatively rare but debilitating diagnosis in the pediatric population, and patients with end-stage HCM require heart transplantation. Here, we have examined the transcriptome in ventricular tissue from this patient group to identify cell states and underlying cellular processes unique to pediatric HCM.

Methods: We performed single-nucleus RNA sequencing (snRNA-seq) on explanted hearts at transplant in 3 pediatric patients with end-stage HCM and compared findings to pediatric control and adult HCM.

Results: We identified distinct underlying cellular processes in cardiomyocytes, fibroblasts, endothelial cells, and myeloid cells compared with controls. Pediatric HCM was enriched in cardiomyocytes exhibiting stressed myocardium gene signatures and underlying pathways associated with cardiac hypertrophy; cardiac fibroblasts exhibited activation signatures and compared with adult patients, exhibited heightened downstream processes associated with fibrosis and a unique, myofibroblast-like cluster with increased metabolic stress and antiapoptotic properties. We noted depletion of tissue-resident macrophages and increased vascular remodeling in endothelial cells in pediatric HCM.

Conclusions: Our analysis provides the first snRNA-seq analysis focused on end-stage pediatric HCM. Fibroblast-mediated cellular processes were the most prominent in pediatric HCM, which had more downstream processes associated with fibrosis than did adult HCM.

Background: Familial hypercholesterolemia (FH) is an autosomal dominant genetic disorder that increases risk for premature coronary artery disease and has accessible and effective interventions. The Dutch lipid clinic network is currently the most used diagnostic criterion; however, genetic sequencing provides a definitive diagnosis of FH. The goals of this study were to determine whether germline genetic screening using exome sequencing could be used to efficiently identify individuals who were genotype positive for FH.

Methods: Participants were recruited from 3 geographically and racially diverse sites in the United States (Rochester, MN; Phoenix, AZ; and Jacksonville, FL). Participants underwent Exome+ sequencing (dba Helix, San Mateo, CA) and return of results for specific genetic findings in APOB, LDLR, or PCSK9. A chart review was performed to collect demographics, personal, and family cardiovascular history.

Results: At the time of the study, 84 413 participants were enrolled in the Tapestry study. Annotation and interpretation of all variants in genes for FH resulted in the identification of 419 likely pathogenic and pathogenic variants (prevalence, 0.50%), which included 116 APOB, 298 LDLR, and 5 PCSK9. Sixty-six percent were female, the mean body mass index was 27.3, with 12.3% reporting a history of diabetes. Hypertriglyceridemia (≥150 mg/dL) was present in 39.5% and reduced HDL (<50 mg/dL) was present in 56.7% of patients. 27.5% of patients were not on cholesterol-lowering medications, and only 10% of FH carriers were at goal low-density lipoprotein cholesterol levels. A history of coronary artery disease was reported in 22.4% of the cohort. Nearly 90% of these participants were newly diagnosed carriers of FH. Only 30.8% of confirmed genetic diagnoses of FH satisfied clinical (Dutch lipid clinic network) criteria for a diagnosis.

Conclusions: Our results emphasize the need for wider utilization of germline genetic sequencing for enhanced screening and detection of individuals who have familial hypercholesterolemia.

Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT05212428.

Background: Atherosclerosis is a pathophysiological process common to a range of cardiovascular diseases. We reasoned that considering clinical presentations of atherosclerosis across the coronary, peripheral, and cerebrovasculature as a single entity would enhance statistical power to identify rare genetic variation driving pathological processes across multiple vascular beds.

Methods: We performed an exome-wide association study of atherosclerotic cardiovascular disease in 434 438 UK Biobank participants of European ancestry.

Results: We identified rare, predicted damaging variants in HTRA1, SGTB, and RBM12 to be associated with risk of atherosclerotic cardiovascular disease, independent of known risk factors. Both SGTB and HTRA1 were downregulated in the aorta of patients with coronary artery disease compared with controls. Loss-of-function variants in the RNA-binding protein RBM12 increased the risk of coronary, cerebrovascular, and peripheral vascular diseases to a similar extent. SGTB increased the risk of atherosclerotic cardiovascular disease in the coronary and peripheral circulations but not the cerebrovasculature. While loss-of-function variants in HTRA1 are known to cause monogenic stroke syndromes, we found that damaging missense variants in HTRA1 are associated with increased risk of disease in both the cerebrovascular and coronary circulation. Surprisingly, the increased risk of coronary artery disease was driven predominantly by a single missense variant (p.R227W; minor allele frequency, 0.009). In vitro, the R227W mutant HTRA1 efficiently proteolyzed the disordered substrate casein but not aggregated α-synuclein. In contrast, a stroke risk-raising variant (D320N) could not efficiently process any of the tested substrates.

Conclusions: We identified novel genetic variants predisposing to atherosclerotic cardiovascular diseases that act independently of established cardiovascular risk factors. The observed phenotypic and functional heterogeneities between HTRA1 variants suggest that distinct biochemical mechanisms drive HTRA1-related vascular disease in the brain and heart.