And Clinical Studies Hypertrophic Cardiomyopathy Disease Genes And Duchenne Muscular Dystrophy Family

BackgroundHypertrophic cardiomyopathy （HCM） is an autosomal-dominant monogenic form of cardiac disease caused by a mutation in one of the genes that encode a protein from the sarcomere, Z-disc, or intracellular calcium modulator and is characterized by unexplained left ventricular hypertrophy. It shows high variability in genetic heterogeneity and phenotypic characteristics. The genetic etiology responsible for HCM in many individuals remains unclear. Many causative genes have already been identified, including β-tropomyosin or myosin heavy chain7（MYH7gene）, cardiac myosin binding protein C （MYBPC3gene）, cardiac troponin T type2（TNNT2gene）, cardiac troponin I type3（TNNI3gene）, myosin light chain3（MYL3gene）, myosin light chain2regulatory （MYL2gene）, cardiac a-actin （ACTC gene） and, titin （TTN gene） and etc.Sanger sequencing is the traditional gold standard in the molecule diagnosis of genetic disease, but time-consuming, laborious and expensive to each investigate for the known candidate genes, especially in HCM. Next generation sequencing technology, with features of high through put, rapid sequencing and low cost, brings revolutionary changes in the fields of detecting gene mutations. The process of using this method to dectect mutations is simple. Researchers can combine whole genomere sequencing, target sequencing and transcriptome sequencing to dectect mutations in all-around, high accurate way.ObjectiveOur aims are to identify the disease-causing gene mutation with familial hypertrophic cardiomyopathy （FHCM） by next generation sequencing, and to analyze the correlation between their genotype and phenotype, prognosis.MethodsWe choose two Chinese pedigrees with HCM and extracted their DNA from whole blood. According to each of the21established HCM genes, the exons in the functional regions of the genes with mutation were amplified with PCR by targeted next-generation DNA sequencing. Proband were sequenced with the next generation DNA sequencing method. According to the results of sequencing, the probands were followed by Sanger sequencing, and the exon in the functional regions of the gene were amplified with PCR and the products were sequenced for their family members. The relation between the genotype and phenotype was analyzed in these families, and the products were directly sequenced.100normal subjects were recruited as control.ResultsOne missence mutation c.1987G>A （Arg663Cys） was identified in exon18of the beta myosin heavy chain gene in one family hypertrophic cardiomyopathy by next generation sequencing. Screening for of her family members by Sanger sequencing, and there are4family members also with mutation Arg663Cys in Exon18of the beta myosin heavy chain gene. The results of genetic test were normal in one hundred controls. The patients with mutation Arg663Cys clinically showed chest pain early, syncope, or sudden cardiac death. After undergoing Morrow operation, the proband had recovered well, and in the follow-up period for two years, she never feels chest pain and syncope.A novel frame shift mutation c.1374delC （p.R458Rfs） was identified in exon14of the cardiac myosin binding protein C gene in pedigree2. Screening for of her family members by Sanger sequencing, and there are3family members also with mutation R458Rfs in Exon14of MYBPC3gene. The results of genetic test were normal in one hundred controls. However, the members of the same HCM family with the R458Rfs mutation showed differences in phenotype and prognosis.ConclusionsThe mutation Arg663Cys in Exon18of beta myosin heavy chain gene is the disease-causing gene in family1by next generation sequencing. The symptoms of patients occur early associated with left ventricular outflow tract obstruction and show chest pain, syncope and sudden death. Their prognosis seems poor in this pedigree of HCM. However, Morrow operation treatment can relieve symptoms and improve prognosis if the patients can actively carry out surgery.A novel frame shift mutation c.1374delC （p.R458Rfs） was identified in exon14of the cardiac myosin binding protein C gene in pedigree2. The patients with this mutation clinically showed differences in phenotype and prognosis. The heterogeneity suggested that multiple factors may be involved in the pathogenesis of HCM. Objective:We aimed to retrospectively analyze the clinical features and prognosis of Hypertrophic cardiomyopathy patients with left ventricular thrombus.Methods:We retrospectively analyzed the data of HCM patients with left ventricular thrombus diagnosed by CMR in FuWai Hospital from January2002to December2012, and followed-up their survival states.Results:Left ventricular thrombosis was confirmed by MRI in6cases of HCM （thrombosis group）, and no left ventricular thrombosis in284cases of HCM （no thrombus group）, the ratio of family history of thrombosis group, ventricular arrhythmia, left atrial diameter, left ventricular diameter and ventricular aneurysm were significantly higher than those without thrombosis group （p<0.05）, and left ventricular ejection fraction and outflow tract obstruction was significantly lower than no thrombus group （p<0.05）.All patients received anticoagulation therapy with warfarin. During follow up （17-59） months, no thromboembolic events was recorded, and thrombus disappear in2patients.3cases died of heart failure and SCD. One patient received heart transplantation.Conclusion:Left ventricular thrombosis was seen in Hypertrophic cardiomyopathy patients with left ventricular aneurysm and lower left ventricular ejection fraction. Ventricular arrhythmia and poor prognosis were found in the majority of patients. Although embolic events occurred because of the left ventricular thrombus, warfarin can cure them. Background:Duchenne’s or Becker’s muscular dystrophy is a serious X-linked neuromuscular disorder. Mutations in the dystrophin gene on chromosome Xp21.1. have been reported to cause BMD. It primarily involved the skeletal muscle, characterized by weakness and muscle atrophy of hereditary muscle disease following as low progressive increase of symmetry. DMD is usually with serious condition and with a poor prognosis. BMD patients can usually walk and have a near normal life span, and there is a chance of them developing cardiac problems.Objective:To study the clinical characteristics and genetic analysis and management of Becker’s muscular dystrophy combined with cardiac involvement, and to expand our understanding of this disorder.Methods:The proband and the family members had genetic testing, and these subjects also had physical examination and received muscle biopsy and routine pathological checks and cardiac evaluation. One hundred control subjects without diagnostic features of BMD were also recruited. Genomic DNA was extracted from leukocytes of peripheral blood from the patients and the control subjects. We screened the dystrophin gene in the indexes, and also screened for the mutation in their families and100controls.Results:The proband was diagnosed with BMD by the identification of a mutation （c.4998₅000Del GCA, p.1667delAla） in the exon35of the dystrophin gene. Three cases were diagnosed with BMD by the identification of this mutation. All genetically affected subjects had a history of weakness of the quadriceps femoris as well as increased serum creatine kinase level at rest and cardiac involvement. After heart transplantation, the proband recovered well. Conclusion:Genetic analysis enables a precise diagnosis of BMD, and heart transplantation is an effective treatment for the patient with severe heart failure.