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The heart muscle diseases hypertrophic (HCM) and dilated (DCM) cardiomyopathies are leading causes of sudden death and heart failure in young, otherwise healthy, individuals. We conducted genome-wide association studies and multi-trait analyses in HCM (1,733 cases), DCM (5,521 cases) and nine left ventricular (LV) traits (19,260 UK Biobank participants with structurally normal hearts). We identified 16 loci associated with HCM, 13 with DCM and 23 with LV traits. We show strong genetic correlations between LV traits and cardiomyopathies, with opposing effects in HCM and DCM. Two-sample Mendelian randomization supports a causal association linking increased LV contractility with HCM risk. A polygenic risk score explains a significant portion of phenotypic variability in carriers of HCM-causing rare variants. Our findings thus provide evidence that polygenic risk score may account for variability in Mendelian diseases. More broadly, we provide insights into how genetic pathways may lead to distinct disorders through opposing genetic effects. Genome-wide analyses identify multiple loci associated with hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM) and left ventricular (LV) traits. Cardiomyopathies exhibit strong genetic correlations with LV traits, with opposing effects in HCM and DCM.

Hypertrophic cardiomyopathy (HCM) is a common, serious, genetic heart disorder. Rare pathogenic variants in sarcomere genes cause HCM, but with unexplained phenotypic heterogeneity. Moreover, most patients do not carry such variants. We report a genome-wide association study of 2,780 cases and 47,486 controls that identified 12 genome-wide-significant susceptibility loci for HCM. Single-nucleotide polymorphism heritability indicated a strong polygenic influence, especially for sarcomere-negative HCM (64% of cases; h 2 g  = 0.34 ± 0.02). A genetic risk score showed substantial influence on the odds of HCM in a validation study, halving the odds in the lowest quintile and doubling them in the highest quintile, and also influenced phenotypic severity in sarcomere variant carriers. Mendelian randomization identified diastolic blood pressure (DBP) as a key modifiable risk factor for sarcomere-negative HCM, with a one standard deviation increase in DBP increasing the HCM risk fourfold. Common variants and modifiable risk factors have important roles in HCM that we suggest will be clinically actionable. Genome-wide association analyses identify 12 susceptibility loci for hypertrophic cardiomyopathy (HCM). A genetic risk score for HCM was associated with disease status in a validation study and influenced phenotypic severity in carriers of risk variants in sarcomere genes.

Hypertrophic cardiomyopathy (HCM) is a hereditary disease of the myocardium characterized by asymmetric hypertrophy (mainly the left ventricle) not caused by pressure or volume load. Most cases of HCM are caused by genetic mutations, particularly in the gene encoding cardiac myosin, such as MYH7, TNNT2, and MYBPC3. These mutations are usually inherited autosomal dominantly. Approximately 30–60% of HCM patients have a family history of similar cases among their immediate relatives. This underscores the significance of genetic factors in the development of HCM. Therefore, we summarized the gene mutation mechanisms associated with the onset of HCM and potential treatment directions. We aim to improve patient outcomes by increasing doctors’ awareness of genetic counseling, early diagnosis, and identification of asymptomatic patients. Additionally, we offer valuable insights for future research directions, as well as for early diagnosis and intervention.

Hypertrophic cardiomyopathy (HCM) is the most prevalent inherited cardiac disease in humans and cats and lacks efficacious pharmacologic interventions in the preclinical phase of disease. LV outflow tract obstruction (LVOTO) is commonly observed in HCM-affected patients and is a primary driver of heart failure symptoms and reduced quality of life. Novel small-molecule cardiac myosin inhibitors target actin-myosin interactions to alleviate overactive protein interactions. A prospective, randomized, controlled cross-over study was performed to evaluate pharmacodynamic effects of two doses (0.3 and 1 mg/kg) of a next-in-class cardiac myosin inhibitor, aficamten (CK-3773274, CK-274), on cardiac function in cats with the A31P MYBPC3 mutation and oHCM. Dose-dependent reductions in LV systolic function, LVOT pressure gradient, and isovolumetric relaxation times compared to baseline were observed. Promising beneficial effects of reduced systolic function warrant further studies of this next-in-class therapeutic to evaluate the benefit of long-term administration in this patient population.

Hypertrophic cardiomyopathy (HCM) is often caused by sarcomere gene mutations, resulting in left ventricular hypertrophy (LVH), myocardial fibrosis, and increased risk of sudden cardiac death and heart failure. Studies in mouse models of sarcomeric HCM demonstrated that early treatment with an angiotensin receptor blocker (ARB) reduced development of LVH and fibrosis. In contrast, prior human studies using ARBs for HCM have targeted heterogeneous adult cohorts with well-established disease. The VANISH trial is testing the safety and feasibility of disease-modifying therapy with an ARB in genotyped HCM patients with early disease. A randomized, placebo-controlled, double-blind clinical trial is being conducted in sarcomere mutation carriers, 8 to 45 years old, with HCM and no/minimal symptoms, or those with early phenotypic manifestations but no LVH. Participants are randomly assigned to receive valsartan 80 to 320 mg daily (depending on age and weight) or placebo. The primary endpoint is a composite of 9 z-scores in domains representing myocardial injury/hemodynamic stress, cardiac morphology, and function. Total z-scores reflecting change from baseline to final visits will be compared between treatment groups. Secondary endpoints will assess the impact of treatment on mutation carriers without LVH, and analyze the influence of age, sex, and genotype. The VANISH trial is testing a new strategy of disease modification for treating sarcomere mutation carriers with early HCM, and those at risk for its development. In addition, further insight into disease mechanisms, response to therapy, and phenotypic evolution will be gained.

Hypertrophic cardiomyopathy (HCM) is widely recognized as one of the most common inheritable cardiac disorders. Since its initial description over 60 years ago, advances in multimodality imaging and translational genetics have revolutionized our understanding of the disorder. The diagnosis and management of patients with HCM are optimized with a multidisciplinary approach. This, along with increased safety and efficacy of medical, percutaneous, and surgical therapies for HCM, has afforded more personalized care and improved outcomes for this patient population. In this review, we will discuss our modern understanding of the molecular pathophysiology that underlies HCM. We will describe the range of clinical presentations and discuss the role of genetic testing in diagnosis. Finally, we will summarize management strategies for the hemodynamic subtypes of HCM with specific emphasis on the rationale and evidence for the use of implantable cardioverter defibrillators, septal reduction therapy, and cardiac myosin inhibitors.

This study reports on a Chinese Han cardiomyopathy family line carrying the MYH7 c.2770G > A (p.Glu924Lys) mutation. This mutation has been shown to result in cross-generational phenotypic heterogeneity between hypertrophic cardiomyopathy (HCM) and restrictive cardiomyopathy (RCM). The proband was a 17-year-old male diagnosed with hypertrophic obstructive cardiomyopathy (HOCM) due to post-exercise syncope, which resolved after septal septectomy. Family lineage analysis revealed that the mother (RCM, NYHA class III) and uncle (RCM, NYHA class IV) of the proband presented with bi-atrial enlargement and reduced systolic function (LVEF 45%), whereas aunts and cousins ( n  = 3) had asymptomatic hypertrophic non-obstructive cardiomyopathy (HNCM). Whole exome sequencing identified six family members carrying the MYH7 c.2770G > A heterozygous mutation with an ACMG rating of probable pathogenic (PM2 + PP3 + PP5). The subjects carrying the mutation exhibited three distinct phenotypes: HOCM (1 case), HNCM (3 cases), and RCM (2 cases). However, the mutation locus did not fully co-segregate with the observed phenotypes. The study hypothesises that the MYH7 c.2770G > A mutation can lead to transgenerational and multisubtype cardiomyopathy phenotypic heterogeneity, and that the mechanism may be related to transcriptional regulation and epigenetic modifications. It is imperative that early genetic screening and clinical intervention are implemented to enhance the prognosis of affected families.

Familial hypertrophic cardiomyopathy (HCM) is the most common genetic cardiovascular disease (CVD). Related mutations contributing to hypercontractility and poor relaxation in HCM are not completely understood. This study aimed to explore and verify a novel variant of cardiac myosin-binding protein C (cMyBP-C, encoded by MYBPC3) in an HCM family. Clinical information and cardiac parameters were collected in the pedigree. Genomic DNA was extracted from peripheral blood and second-generation sequencing technology was used to investigate the proband and his family members. Subsequent sequence analysis was performed with DNAMAN software. The cardiac expression levels of MYBPC3 mRNA and cMyBP-C protein were assessed using RT-qPCR and Western blot analysis, respectively. Typical interventricular septal thickening was detected in all four HCM patients without left ventricular outflow tract obstruction. The c.1042_1043insCGGCA mutation in MYBPC3 was verified in the proband and family members. In silico analysis of the mutation revealed that c.1042_1043insCGGCA led to a shift in the sequence of nucleotides, creating a premature stop codon at the new reading frame. RT-qPCR analysis of MYBPC3 mRNA revealed a marked reduction in HCM heart compared to the normal controls (P < 0.05). Consistently, Western blot analysis showed significantly reduced expression of cMyBP-C in the pedigree in comparison with the controls (P < 0.05). The novel c.1042_1043insCGGCA MYBPC3 mutation is a genetic basis for HCM due to c-MyBP-C haploinsufficiency.

Patients with hypertrophic cardiomyopathy (HC) caused by compound variants have severe clinical manifestations, but significant clinical heterogeneity remains. Clinical diversity in these patients may result from different combinations of variants. We analyzed the role of cis-compound variants in a Chinese HC pedigree. Exome sequencing was performed in the proband. Identified variants were detected with bi-directional Sanger sequencing in a pedigree that comprised 3 generations and 28 family members. Follow-up was performed for 16 years. Two missense variants (c.2465T>C, p.Met822Thr; c.4258C>T, p.Arg1420Trp) were identified in the MYH7 gene. These variants were absent in our 761 in-house people without HC and predicted to be pathogenic.Both variants were detected in 11 family members, thus they were believed to inherit cis. In the 11 members, only 5 developed HC, the other 6 were asymptomatic variant carriers with an abnormal electrocardiogram. The HC members had mild hypertrophy with a maximum left ventricular wall thickness of 13 to 21 mm and showed a low incidence of cardiovascular events. In conclusion, the cis-compound variants of Met822Thr and Arg1420Trp in MYH7 are causal but relatively benign, variants associated with familial HC. This finding suggests that different types of compound variants might need to be analyzed for a genotype–phenotype study.

IntroductionGenetic testing for hypertrophic cardiomyopathy (HCM) in the era of genomics brings unique challenges for genetic counselling. The number of genes routinely included in an HCM gene panel has increased markedly, many with minimal if any robust evidence of gene–disease association. Subsequently, there is a greater chance of uncertain genetic findings. The responsibility of communicating this information with at-risk relatives lies with the index case (proband). We have developed a communication aid to assist with the delivery of genetic results to the proband. We have previously shown the aid is feasible and acceptable and have now developed a study protocol for a randomised controlled trial of a genetic counsellor-led intervention incorporating the communication aid.Methods and analysisThis is a prospective randomised controlled trial. We will investigate the impact of a genetic counsellor-led intervention to return proband genetic results using a custom-designed communication aid. We aim to improve knowledge and empowerment. The primary outcome of this trial is the ability and confidence of the proband to communicate genetic results to at-risk relatives. Secondary outcomes will assess genetic knowledge, satisfaction with services, outcomes from genetic counselling and psychological adaptation to genetic information.Ethics and disseminationThis study has been approved by and is in strict accordance with the Sydney Local Health District Ethics Review Committee (X16-0030; 22/01/2016; version 1). Results from this trial will be prepared as a manuscript and submitted to peer-reviewed journals for publication as well as submission for presentation at national and international meetings.Trial registration numberACTRN12617000706370.