Hypertrophic cardiomyopathy (HCM) is the most common monogenic inherited myocardial disease in children, and mutations in sarcomere genes (such as MYH7 and MYBPC3) are the most common genetic etiology of HCM, among which mutations in the MYH7 gene are the most common and account for 30%-50%. MYH7 gene mutations have the characteristics of being affected by environmental factors, coexisting with multiple genetic variations, and age-dependent penetrance, which leads to different or overlapping clinical phenotypes in children, including various cardiomyopathies and skeletal myopathies. At present, the pathogenesis, course, and prognosis of HCM caused by MYH7 gene mutations in children remain unclear. This article summarizes the possible pathogenesis, clinical phenotype, and treatment of HCM caused by MYH7 gene mutations, in order to facilitate the accurate prognostic evaluation and individualized management and treatment of the children with this disorder.
Child ; Humans ; Cardiomyopathy, Hypertrophic/therapy* ; Phenotype ; Troponin T/genetics* ; Mutation ; Carrier Proteins/genetics* ; Myosin Heavy Chains/genetics* ; Cardiac Myosins/genetics*

OBJECTIVES: To investigate the clinical phenotype and genotype characteristics of children withcardiomyopathy (CM) associated with MYH7 gene mutation. METHODS: A retrospective analysis was conducted on the medical data of five children with CM caused by MYH7 gene mutation who were diagnosed and treated in the Department of Cardiology, Hebei Children's Hospital. RESULTS: Among the five children with CM, there were three girls and two boys, all of whom carried MYH7 gene mutation. Seven mutation sites were identified, among which five were not reported before. Among the five children, there were three children with hypertrophic cardiomyopathy, one child with dilated cardiomyopathy, and one child with noncompaction cardiomyopathy. The age ranged from 6 to 156 months at the initial diagnosis. At the initial diagnosis, two children had the manifestations of heart failure such as cough, shortness of breath, poor feeding, and cyanosis of lips, as well as delayed development; one child had palpitation, blackness, and syncope; one child had fever, runny nose, and abnormal liver function; all five children had a reduction in activity endurance. All five children received pharmacotherapy for improving cardiac function and survived after follow-up for 7-24 months. CONCLUSIONS The age of onset varies in children with CM caused by MYH7 gene mutation, and most children lack specific clinical manifestations at the initial diagnosis and may have the phenotype of hypertrophic cardiomyopathy, dilated cardiomyopathy or noncompaction cardiomyopathy. The children receiving early genetic diagnosis and pharmacological intervention result in a favorable short-term prognosis.
Male ; Female ; Child ; Humans ; Retrospective Studies ; Cardiomyopathy, Dilated/genetics* ; Pedigree ; Phenotype ; Genotype ; Mutation ; Cardiomyopathy, Hypertrophic/diagnosis* ; Myosin Heavy Chains/genetics* ; Cardiac Myosins/genetics*

Objective: To explore the relationship between pathogenic gene, mutation and phenotype of left ventricular noncompaction (LVNC) patients and their family members. Methods: The subjects were the proband with LVNC and her family members. The medical history including electrocardiogram, echocardiography and cardiac magnetic resonance examination of the proband and family members were collected. Whole exome sequencing of the proband was performed, bioinformatics analysis focused on the genes related to hereditary cardiomyopathy. Candidate pathogenic sites were validated by Sanger sequencing. The clinical interpretation of sequence variants were classified according to American College of Medical Genetics and Genomics (ACMG) guidelines. Results: The proband carried a heterozygous variation of the MYBPC3 gene c.C2827T and the MYH7 gene c.G2221C. The proband's sister carried heterozygous variation of MYBPC3 gene c.C2827T. According to the ACMG guidelines, the variant was determined to be pathogenic. Conclusion: The missense variant of MYBPC3 gene c.C2827T and MYH7 gene c.G2221C are identified from the proband with LVNC and her family member, which provides a genetic basis for clinical diagnosis and genetic counseling of the patients and the family members with LVNC.
Female ; Humans ; Cardiac Myosins/genetics* ; Heart Defects, Congenital ; Mutation ; Mutation, Missense ; Myosin Heavy Chains/genetics* ; Pedigree ; Phenotype

Objective: To explore the relationship between pathogenic gene, mutation and phenotype of left ventricular noncompaction (LVNC) patients and their family members. Methods: The subjects were the proband with LVNC and her family members. The medical history including electrocardiogram, echocardiography and cardiac magnetic resonance examination of the proband and family members were collected. Whole exome sequencing of the proband was performed, bioinformatics analysis focused on the genes related to hereditary cardiomyopathy. Candidate pathogenic sites were validated by Sanger sequencing. The clinical interpretation of sequence variants were classified according to American College of Medical Genetics and Genomics (ACMG) guidelines. Results: The proband carried a heterozygous variation of the MYBPC3 gene c.C2827T and the MYH7 gene c.G2221C. The proband's sister carried heterozygous variation of MYBPC3 gene c.C2827T. According to the ACMG guidelines, the variant was determined to be pathogenic. Conclusion: The missense variant of MYBPC3 gene c.C2827T and MYH7 gene c.G2221C are identified from the proband with LVNC and her family member, which provides a genetic basis for clinical diagnosis and genetic counseling of the patients and the family members with LVNC.
Female ; Humans ; Cardiac Myosins/genetics* ; Heart Defects, Congenital ; Mutation ; Mutation, Missense ; Myosin Heavy Chains/genetics* ; Pedigree ; Phenotype

OBJECTIVE: To analyze the clinical phenotype and MYH7 gene variant in a Chinese pedigree affected with hypertrophic cardiomyopathy (HCM). METHODS: The proband was screened for variant of 96 cardiomyopathy-associated genes by exonic amplification and high-throughput sequencing. Candidate variant was verified by Sanger sequencing among 300 healthy controls as well as family members of the proband. Co-segregation analysis of genotypes and clinical phenotypes was carried out for the pedigree. Clustal X software was used to analyze the sequence conservation of the variant among various species, and its pathogenicity was predicted by using bioinformatics software. RESULTS: 6 out of 12 members from this pedigree were found to harbor heterozygous c.4124A>G (p.Tyr1375Cys) variant of the MYH7 gene, among whom five were diagnosed with HCM. The remaining one had failed to meet the diagnostic criteria for HCM, but had abnormal ECG. The same variant was not found in the 300 healthy controls. Amino acid sequence analysis showed that the variant is located in a highly conserved region, and bioinformatics analysis predicted that this variant may affect protein function and has a deleterious effect. Based on the American College of Medical Genetics and Genomics (ACMG) guidelines, the variant was predicted to be likely pathogenic (PM2+ PP1_Moderate+PP3+PP5). CONCLUSION The c.4124A>G (p.Tyr1375Cys) variant of the MYH7 gene probably underlay the pathogenesis in this pedigree. Above finding has important value for the early diagnosis of patients with HCM.
Cardiac Myosins/genetics* ; Cardiomyopathy, Hypertrophic/genetics* ; Genotype ; Humans ; Mutation ; Myosin Heavy Chains/genetics* ; Pedigree ; Phenotype

Objective: To evaluate the cardiac functional changes in hypertrophic cardiomyopathy(HCM) patients with β-myosin heavy chain gene (MYH7) mutations by three-dimensional (3D) speckle tracking imaging(3D-STI) and conventional echocardiography modalities, and then to explore the potential predictors of adverse cardiovascular events in these patients. Methods: A consecutive series of 192 HCM patients admitted in our center from October 2014 to October 2016 were genetically screened to identify MYH7 mutations in this retrospective study. A total of 43 HCM patients with MYH7 mutations were enrolled. The patients were divided into events group(n=13) and no event group(n=30) according to the presence or absence of adverse cardiovascular events(primary and secondary endpoints). All patients were followed up to January 2019 after comprehensive evaluation of 3D-STI, two-dimensional and Doppler echocardiography. The adverse cardiovascular events were recorded. Results: The median follow up time was 1 012 (812, 1 330) days. During follow-up, 13 patients (30.2%) reached endpoints: 6 cases of the primary endpoints(2 cases of sudden cardiac death(SCD), 3 cases of survival after defibrillation, and 1 case of appropriate implantable cardioverter-defibrillator(ICD) discharge); 7 cases of the second endpoints(5 cases of heart failure hospitalization, 1 case of syncope and cardioversion due to supraventricular tachycardia, and 1 case of end-stage HCM). Patients with adverse cardiovascular events had higher prevalence of syncope and risk of SCD, enlarged left atrial volume index(LAVI) and reduced 3D left ventricular global longitudinal train (3D-GLS), as compared to those without adverse events(all P<0.05). The multivariate Cox regression analysis showed that reduced 3D-GLS(HR=0.814, 95%CI 0.663-0.999, P=0.049) was an independent predictor for adverse cardiovascular events. The cutoff value of 3D-GLS≤13.67% was linked with significantly increased risk of adverse cardiovascular events in this patient cohort(AUC=0.753, 95%CI 0.558-0.948, sensitivity 86%, specificity 69%, P<0.05). The Kaplan-Meier analysis indicated that the patients with the 3D-GLS≤ 13.67% faced higher risk of death than those with 3D-GLS>13.67%. Conclusion: 3D-GLS is useful on predicting adverse cardiovascular events in HCM patients with MYH7 mutations.
Cardiac Myosins/genetics* ; Cardiomyopathy, Hypertrophic/genetics* ; Echocardiography ; Humans ; Mutation ; Myosin Heavy Chains/genetics* ; Predictive Value of Tests ; Retrospective Studies ; Risk Factors

Adolescent ; Adult ; Asian Continental Ancestry Group ; Cardiac Myosins ; genetics ; Child ; Creatine Kinase ; blood ; Distal Myopathies ; blood ; genetics ; Female ; Genetic Predisposition to Disease ; Humans ; Male ; Middle Aged ; Mutation ; genetics ; Mutation, Missense ; genetics ; Myosin Heavy Chains ; genetics ; Pedigree ; Polymorphism, Single Nucleotide ; genetics ; Young Adult

OBJECTIVETo analyze the phenotype-genotype correlation of MYH7-V878A mutation.

METHODSExonic amplification and high-throughput sequencing of 96-cardiovascular disease-related genes were carried out on probands from 210 pedigrees affected with hypertrophic cardiomyopathy (HCM). For the probands, their family members, and 300 healthy volunteers, the identified MYH7-V878A mutation was verified by Sanger sequencing. Information of the HCM patients and their family members, including clinical data, physical examination, echocardiography (UCG), electrocardiography (ECG), and conserved sequence of the mutation among various species were analyzed.

RESULTSA MYH7-V878A mutation was detected in five HCM pedigrees containing 31 family members. Fourteen members have carried the mutation, among whom 11 were diagnosed with HCM, while 3 did not meet the diagnostic criteria. Some of the fourteen members also carried other mutations. Family members not carrying the mutation had normal UCG and ECG. No MYH7-V878A mutation was found among the 300 healthy volunteers. Analysis of sequence conservation showed that the amino acid is located in highly conserved regions among various species.

CONCLUSIONMYH7-V878A is a hot spot among ethnic Han Chinese with a high penetrance. Functional analysis of the conserved sequences suggested that the mutation may cause significant alteration of the function. MYH7-V878A has a significant value for the early diagnosis of HCM.

Adult ; Amino Acid Sequence ; Asian Continental Ancestry Group ; genetics ; Cardiac Myosins ; genetics ; Cardiomyopathy, Hypertrophic ; genetics ; Female ; Genetic Association Studies ; methods ; Genotype ; Humans ; Male ; Middle Aged ; Mutation ; genetics ; Myosin Heavy Chains ; genetics ; Pedigree ; Phenotype ; Young Adult

OBJECTIVETo identify the casual mutation of a Chinese pedigree with hypertrophic cardiomyopathy (HCM), and to analyze the genotype-phenotype relationship.

METHODSThe coding exons of 26 reported disease genes were sequenced by targeted resequencing in the proband and the identified mutation were detected with bi-directional Sanger sequencing in all family members and 307 healthy controls. The genotype-phenotype correlation was analyzed in the family.

RESULTSA missense mutation (c.2191C > T, p. Pro731Ser) in the 20th exon of MYH7 gene was identified. This mutation was absent in 307 healthy controls and predicted to be pathogenic by PolyPhen-HCM. Totally 13 family members carried this mutation, including 10 patients with HCM and 3 asymptomatic mutation carriers. The proband manifested severe congestive heart failure and 8 patients expressed various clinical manifestations of heart failure, including dyspnea, palpitations, chest pain, amaurosis or syncope. Five patients were diagnosed as HCM at the age of 16 or younger. One family member suffered sudden cardiac death.

CONCLUSIONSThe Pro731Ser of MYH7 gene mutation is a causal and malignant mutation linked with familiar HCM.

Adolescent ; Asian Continental Ancestry Group ; Base Sequence ; Cardiomyopathy, Hypertrophic ; ethnology ; genetics ; Death, Sudden, Cardiac ; Exons ; Humans ; Mutation, Missense ; Myosin Heavy Chains ; genetics ; Pedigree ; Phenotype ; Research Design ; Ventricular Myosins

OBJECTIVETo detect the gene mutations of beta-myosin heavy chain gene (MYH7) in Chinese pedigrees with hypertrophic cardiomyopathy (HCM), and to analyze the correlation between the genotype and phenotype.

METHODSExons 3, 5, 7-9, 11-16 and 18-23 of the MYH7 gene were amplified with PCR in three Chinese pedigrees with HCM. The products were sequenced. Sequence alignment between the detected and the standard sequences was performed.

RESULTSA missense mutation of Thr441Met in exon 14 was identified in a pedigree, which was not detected in the controls. Several synonymous mutations of MYH7 gene were detected in the three pedigrees.

CONCLUSIONThe mutation of Thr441Met, located in the actin binding domain of the globular head, was first identified in Chinese. It probably caused HCM. HCM is a heterogeneous disease. Many factors are involved in the process of its occurrence and development.

Adult ; Amino Acid Sequence ; Animals ; Base Sequence ; Cardiac Myosins ; Cardiomyopathy, Hypertrophic ; genetics ; DNA Mutational Analysis ; Female ; Genotype ; Humans ; Male ; Middle Aged ; Molecular Sequence Data ; Mutation ; Myosin Heavy Chains ; chemistry ; genetics ; Pedigree ; Phenotype