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Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two long-living brothers of dystrophin-related muscular dystrophy with an in-frame deletion of exon 3 of the dystrophin gene were described. Weakness of the lower extremities and pseudohypertrophy of calf muscles began at the age of 2 years in the elder brother and 4 years in the younger brother, respectively. Clinical symptoms progressed rapidly and both of them lost ambulation and became wheelchair bound at the age of 11-12 years. However, the progression of the disease process slowed in late teens, and now at the age of 36 and 33 years, respectively, they do not have respiratory or cardiac insufficiency, although they are disabled severely. Southern blotting with the entire dystrophin cDNAs, cDNA 1-2a, 2b-3, 4-5a, 5b-7, 8, and 9-14, revealed a single deletion of exon 3 in the 2 brothers. The mother was shown to be a heterozygote for this mutation. The unique clinical features of these brothers were presumed due to the following 2 factors: (1) a single deletion of exon 3 is an in-frame deletion of the dystrophin gene, and (2) exon 3 corresponds to a unique domain of the dystrophin molecule; the amino-terminal region which is highly homologous to the actin-binding-region of alpha-actinin. We consider that these 2 brothers are compatible with the so-called frame-shift hypothesis of Duchenne/Becker muscular dystrophy (DMD/BMD) phenotype, although they are diagnosed DMD by the classification method based on the patients' age of becoming permanently wheelchair bound.
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PMID:[Two long-living brothers of dystrophin-related muscular dystrophy with an in-frame deletion of exon 3 of the dystrophin gene--clinical features and diagnosis]. 189 67

We review recent publications that use molecular and cellular biology to explore the diagnosis and treatment of cardiovascular diseases that have relevance to heart failure. Familial hypertrophic cardiomyopathy has now been shown to be due to mutations not only in the previously described beta myosin heavy chain gene, but also in the troponin T and alpha-tropomyosin genes, thus providing some symmetry to the idea that this is a molecular disease of the sarcomere. The basis for a type of familial dilated cardiomyopathy without substantial skeletal muscle involvement, caused by a mutation in the dystrophin gene, has been explored. However, by-and-large, the disease basis for most patients with dilated cardiomyopathy remains a molecular mystery. The role of a polymorphism in the angiotensin-converting enzyme gene was examined as a risk factor for a number of cardiovascular diseases. In animal models, the hypothesis that the devolution from hypertrophy to heart failure includes alterations in the molecular direction of extracellular matrix production gained some support. The experimental foundation was laid this year for the concept of and approach to cardiomyocytoplasty--the molecular and cellular treatment of heart failure by augmentation, repair, or replacement of cardiac myocytes--by experiments in cardiac gene transfer and transgenic animals. Gene causes and cures for restenosis after angioplasty garnered considerable attention. As we gain greater understanding of the molecular basis for disease, we will also have to increase our wisdom in the application of genetic testing.
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PMID:The molecular and cellular biology of heart failure. 761 72

We present a 17-year-old boy with Becker muscular dystrophy (BMD) who developed hyperthermia and heart failure after general anesthesia. He presented clinical features of malignant hyperthermia (MH), and had masseter spasm and elevated body temperature (38.7 degrees C) with very high serum CK activity (107,000 IUl-1). Dystrophin tests confirmed a clinical diagnosis of BMD in the patient, i.e. faint and patchy immunostaining pattern of skeletal muscle, truncated dystrophin protein and a deletion of exons 3 and 4 of the dystrophin gene. To inquire into the mechanism of MH associated in the patient, we tested caffeine contracture reaction by the skinned fiber method. We found an increased sensitivity to caffeine only in type 1 muscle fibers. The rate of Ca(2+)-induced Ca2+ release (CICR) was normal, suggesting that the mechanism of "MH" observed in our patient with BMD is not the same as that of classical MH. A possible mechanism might be related to derangements of the sarcoplasmic reticulum membrane in BMD, which sensitize the membrane to caffeine or other agents.
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PMID:Malignant hyperthermia in a patient with Becker muscular dystrophy: dystrophin analysis and caffeine contracture study. 771 42

We review recent publications involving molecular biology and heart failure. There was some further evolution in our knowledge of the basis for the simplest of molecular genetic diseases--single gene disorders. This year, hypertrophic cardiomyopathy had further genes identified as causative mutations; was shown to have the same genetic defects in spontaneous and familial cases; and demonstrated phenotypic alteration by environmental factors. Several rare cardiomyopathies were linked to the dystrophin gene, previously identified as the mutated gene responsible for forms of muscular dystrophy. Molecular methods were applied to linking viral infection to dilated cardiomyopathy by hunting for viral genomes in heart muscle, and for seeking mutations in mitochondrial DNA. Molecular treatment of restenosis after angioplasty showed promise through the application of gene transfer to vascular tissue by oligonucleotides as well as adenovirus-mediated gene transfer. The ethical aspects of diagnosing and treating human disease using genetic information, which receive frequent discussion in print, are also reviewed.
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PMID:The molecular and cellular biology of heart failure. 804 84

Hypertrophic cardiomyopathy is a heterogeneous disease with autosomal dominant Mendelian inheritance. In 1989, the 1st locus for hypertrophic cardiomyopathy was mapped to cardiac myosin genes located on chromosome 14q1. Soon, several mutations that cosegregated with inheritance of the disease were identified in the beta-myosin heavy chain gene, or MHY7. More than 30 missense mutations and 1 deletion mutation in the beta-myosin heavy chain gene have since been described. Recently, expression of both the mutant beta-myosin heavy chain mRNA and the mutant protein has been shown in the cardiac and skeletal muscles of individuals with hypertrophic cardiomyopathy. Characterization of the clinical features of beta-myosin heavy chain mutations has shown that certain mutations, such as Arg403Gln and Arg719Trp mutations, are associated with high rate of sudden cardiac death. In addition to the beta-myosin heavy chain gene, 3 new loci for hypertrophic cardiomyopathy have recently been described, but the candidate genes have not yet been identified. Dilated cardiomyopathy can be inherited as an autosomal dominant, autosomal recessive, and X-linked disease. The familial form of dilated cardiomyopathy comprises approximately 20% of the cases of idiopathic cardiomyopathy. Echocardiographic abnormalities such as left ventricular enlargement are present in 10% of asymptomatic relatives. No gene for familial dilated cardiomyopathy has been identified, but linkage studies using polymorphic, short-tandem repeat markers are ongoing. Dilated cardiomyopathy is a common manifestation of Duchenne/Becker muscular dystrophy. Heart failure is a common cause of death in the affected individuals. The gene responsible for this disease is the dystrophin gene located on X chromosome. There have been reports in these patients of several dystrophin-gene deletion mutations, which result in a decrease in the expression of the dystrophin protein in the cardiac and skeletal tissues. X-linked cardiomyopathy, in which the disease is restricted to the heart, has also been linked to the dystrophin gene. Myotonic dystrophy is an autosomal dominant disease that commonly involves the myocardium and the conduction tissue, resulting in conduction defects and heart failure. Sudden cardiac death is the most common cause of mortality in patients with myotonic dystrophy. Recently, the myotonin protein kinase gene located on chromosome 19 was identified as the gene responsible for this disease. Expansion of the number of trinucleotide repeats in the myotonin protein kinase gene results in myotonic dystrophy. Mutations in mitochondrial DNA have been associated with hypertrophic and dilated cardiomyopathy. The inheritance of mitochondrial cardiomyopathy is maternal and the disease is associated with certain systemic disorders.
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PMID:Molecular basis of hypertrophic and dilated cardiomyopathy. 818 May 12

Patients with Becker muscular dystrophy (BMD) have milder muscular impairment and better prognosis than patients with Duchenne muscular dystrophy (DMD). Another difference is that while cardiac failure due to myocardial involvement is a frequent cause of death in BMD, respiratory failure is the most common cause of death in DMD. We examined cardiac function and the mechanism of cardiac failure in 21 BMD patients aged 3 to 63 years (mean, 40.4) by electrocardiography, mechanocardiography, echocardiography, and post-mortem examination. Diagnosis of BMD was made by characteristic symptoms, dystrophic change in muscle histology, and the followings: 1) a deletion in the dystrophin gene, 2) "patchy" staining of dystrophin on immunocytochemical analysis, 3) abnormal dystrophin size on Western blotting, and 4) presence of a definite carrier in the family. To be diagnosed as BMD, patients exhibited one or more of 1)-3). Patients who were diagnosed only by 4) had a relative who had been diagnosed as BMD by one of 1)-3). The control group included 43 DMD patients (age 4-26 years, mean 16.2) and 20 healthy males (age 15-60 years, mean 33.3). Electrocardiogram showed prominent Q waves in leads II, III, aVF and V6, and tall R in V1, suggesting myocardial injury in the posteroinferior and lateral walls. The ratio of ejection time to pre-ejection period (ET/PEP) decreased to 2.0-3.3 in BMD, and was significantly lower than that in DMD patients with comparable muscle weakness. Left ventricular dilatation became more prominent with age, and end-diastolic left ventricular dimension (EDLVD) averaged 52.3 mm.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Clinical feature and mechanism of cardiac failure in patients with Becker muscular dystrophy]. 819 65

Familial hypertrophic cardiomyopathy (FHCM) is a heterogeneous disease with an autosomal dominant Mendelian inheritance and variable penetrance. Several mutations in the beta-myosin heavy chain (beta MHC) gene, the first gene identified for this disease, have been described that co-segregate with the inheritance of the disease. All the mutations in the beta MHC gene encode for the globular head of the myosin protein except for the deletion mutation which encodes for the carboxy-terminus (rod) of the protein. The clinical features associated with some of the mutations in the beta MHC gene have been characterized. A missense mutation in exon 13 of the beta MHC gene, is associated with a higher incidence of sudden cardiac death and severe form of the disease, while some others are associated with a more benign form of the disease. Recently, three other loci, on chromosomes 1q3, 11q11 and 15q2, for FHCM have been identified and research is ongoing to identify the candidate genes. Cardiac involvement in Duchenne/Becker muscular dystrophy (DMD), and myotonic dystrophy is common. Heart failure due to dilated cardiomyopathy and sudden cardiac death are the common causes of death in these disorders. The genes responsible for DMD and myotonic dystrophy are dystrophin and myotonin protein kinase genes located on chromosomes X and 19 respectively. The disease in DMD is due to deletion mutations in the dystrophin gene, while myotonic dystrophy is due to expansion of the GCT trinucleotide repeats in the myotonin-protein kinase gene. Familial dilated cardiomyopathy comprises 20% of cases of idiopathic dilated cardiomyopathy.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Molecular genetics of cardiomyopathies. 837 3

Dystrophin serves a variety of roles at the cell membrane through its associations, and defects in the dystrophin gene can give rise to muscular dystrophy and genetic cardiomyopathy. We investigated localization of cardiac dystrophin to determine potential intracellular sites of association. Subcellular fractionation revealed that while the majority of dystrophin was associated with the sarcolemma, about 35% of the 427-kDa form of dystrophin was present in the myofibrils. The dystrophin homolog utrophin was detectable only in the sarcolemmal membrane and was absent from the myofibrils as were other sarcolemmal glycoproteins such as adhalin and the sodium-calcium exchanger. Extraction of myofibrils with KC1 and detergents could not solubilize dystrophin. Dystrophin could only be dissociated from the myofibrillar protein complex in 5 M urea followed by sucrose density gradient centrifugation where it co-fractionated with one of two distinctly sedimenting peaks of actin. Immunoelectron microscopy of intracellular regions of cardiac muscle revealed a selective labeling of Z-discs by hystrophin antibodies. In the genetically determined cardiomyopathic hamster, strain CHF 147, the time course of development of cardiac insufficiency correlated with an overall 75% loss of myofibrillar dystrophin. These findings collectively show that a significant pool of the 427-kDa form of cardiac dystrophin was specifically associated with the contractile apparatus at the Z-discs, and its loss correlated with progression to cardiac insufficiency in genetic cardiomyopathy. The loss of distinct cellular pools of dystrophin may contribute to the tissue-specific pathophysiology in muscular dystrophy.
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PMID:The association of cardiac dystrophin with myofibrils/Z-disc regions in cardiac muscle suggests a novel role in the contractile apparatus. 864 39

Cardiac function was examined in 21 patients with Becker muscular dystrophy (BMD) and compared with 43 patients with Duchenne muscular dystrophy (DMD) and 37 healthy control subjects. Electrocardiography showed myocardial damage was most frequently found in the lateral wall, compatible with autopsy findings. The ratio of the preejection period to the ejection time was higher in patients with BMD (0.37 +/- 0.07, mean +/- SD) than in patients with DMD (0.28 +/- 0.05) and healthy controls (0.23 +/- 0.04). Left ventricular dimension and mitral annular size at end diastole in patients with BMD increased to 52.3 +/- 7.7 mm and 28.8 +/- 5.3 mm with age, respectively. In patients with cardiac failure and BMD, mitral regurgitation was observed at a rate of 66.7%. No definite relation between the deleted locus of the dystrophin gene and cardiac failure was found. Because motor dysfunction progresses more slowly in BMD than in DMD, a prolonged work load on the morbid myocardium may lead to dilated cardiomyopathy with mitral regurgitation.
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PMID:Cardiac dysfunction with Becker muscular dystrophy. 880 37

Duchenne and Becker muscular dystrophies (DMD and BMD, respectively) are the most common inherited muscular diseases and caused by mutations in the dystrophin gene. Half to two-thirds of DMD and BMD patients carry deletions (usually of several kilobases of genomic DNA). The clinical progression in DMD and BMD patients with deletions can be predicted in 92% of cases based on whether the deletion maintains or disrupts the translational reading frame (frame-shift hypothesis). However, some exceptional cases have been reported; BMD cases whose dystrophin gene exons 3 to 7 were deleted (out-of-frame), more severe case whose dystrophin gene deletion maintains reading frame but includes N-terminal region, and so on. Splicing mutation is one kind of mutations of dystrophin gene, and usually induced by small mutation of exon-intron boundary sequence. However, intraexonal small mutation also induces exon skipping, due to disruption of exon recognition sequence, which is intraexonal sequence and necessary for splicing of the upstream intron. For molecular diagnosis of DMD/BMD it is important to analyze not only in genomic DNA level, but also in mRNA, protein, and clinical levels. And the relationship between molecular abnormality and clinical phenotype should be examined, especially when extramuscular symptoms (heart failure and mental retardation) are prominent.
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PMID:[Molecular genetics and problems found in genetic diagnosis of Duchenne Becker muscular dystrophy]. 943 21


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