Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0162671 (MELAS)
 587 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We describe a case of a 34-year-old male patient first hospitalized in February '93 for stroke (concomitant dilated-hypertrophic cardiomyopathy was noted), and then in April '93 for congestive heart failure. The presence of myopathy, encephalopathy, lactic acidosis and stroke episode allows for the diagnosis of MELAS syndrome, proven by a specific point mutation in mitochondrial DNA. In this case we were able to observe not only the electrocardiographic and echocardiographic features of hypertrophic cardiomyopathy, previously described in mitochondrial encephalomyopathies, but we were also able to monitor the rapid evolution of this cardiomyopathy towards the hypokinetic dilated form with severe impairment of systolic function; this transition was due to changes in the heart anatomy and structure with reduction in the left ventricular (LV) wall thickness and dilatation of all chambers. The remodeling of LV geometry seems to be not definite and capable of dynamic evolution, as suggested by clinical and echocardiographic findings evaluated six months after the hospitalization. In this patient, we obtained a mid-term favourable clinical outcome using inotropic drugs and Ubiquinone (coenzyme Q), an intermediate substrate of the energetic metabolism, which seems to be poorly synthetized because of the early enzymatic defects in the mitochondrial respiratory chain.
G Ital Cardiol 1995 Jan
PMID:[The MELAS syndrome and dilated-hypertrophic cardiomyopathy: a case report]. 764 13

Cardiac data in adults with mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes (MELAS syndrome) or asymptomatic gene carriers with the mitochondrial deoxyribonucleic acid adenine-to-guanine point mutation at nucleotide pair 3243 are scarce. Twelve subjects (mean age 35 +/- 13 years), 8 with MELAS syndrome (patients) and 4 asymptomatic gene carriers (carriers), were enrolled in the study. Each subject underwent electrocardiography, exercise testing, Holter monitoring, echocardiography, and genetic and biochemical analysis for respiratory chain enzyme activity (complex I rest activity) in skeletal muscle. On electrocardiography and Holter monitoring, none of the subjects had evidence of preexcitation, cardiac arrhythmias, or conduction abnormalities. Patients had significantly lower (42 +/- 17% from normal vs 103 +/- 14%, p <0.02) exercise tolerance. All but 1 of the patients and none of the gene carriers had ragged red fibers on muscle biopsy. The mean percentage of gene mutation in skeletal muscle tended to be higher in patients (53 +/- 19%, range 19% to 73%) compared with carriers (33 +/- 20%, range 15% to 62%). Mean complex I rest activity in patients (36 +/- 18%, range 10% to 58%) was significantly (p <0.01) lower compared with carriers (120 +/- 60%, range 72% to 205%). Left ventricular (LV) abnormalities were confined to patients with MELAS syndrome. Two patients had LV hypertrophy, 5 had LV systolic abnormalities, and 5 had LV diastolic dysfunction. Apart from 1 patient with an isolated LV diastolic abnormality, all patients with LV abnormalities had ragged red fibers. Patients with abnormal systolic LV function had a trend toward a higher percentage of mutated skeletal muscle (59.7 +/- 10.7% vs 35.8 +/- 21.3%, p <0.10) and significantly lower complex I rest activity (26.7 +/- 14.0% vs 97.8% +/- 57.9, p <0.01). In conclusion, none of the MELAS gene carriers had cardiac abnormalities, whereas most patients with the MELAS phenotype, particularly those with ragged red fibers, had LV involvement.
Am J Cardiol 2007 Jan 15
PMID:Cardiac involvement in adults with m.3243A>G MELAS gene mutation. 1722 31

Mitochondrial myopathy may manifest either as isolated myopathy or as a neuromuscular multisystemic disease and is caused by genetic defects in the mitochondrial genome resulting in respiratory chain disorders. MELAS, which is characterised by mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes due to gene mutations in the mitochondrial DNA (adenine-to-guanine transition at nucleotide pair 3243, m.3243A>G), constitutes such a mitochondrial multisystemic disease. Although hypertrophied or dilated cardiomyopathy is quite common in MELAS, there have been no cardiovascular magnetic resonance (CMR)-based studies in these patients so far. This case report represents the first case in which comprehensive CMR and endomyocardial biopsy (EMB) data were obtained in the same patient with mitochondrial myopathy. Late gadolinium enhancement (LGE) imaging demonstrated a unique pattern of myocardial damage and histological work-up revealed the presence of "ragged red fibers" (conglomerates of mitochondria) in the heart tissue verifying the diagnosis of a mitochondrial cardiomyopathy as part of the underlying mitochondrial disease MELAS.
Int J Cardiol 2011 May 19
PMID:CMR gives clue to "ragged red fibers" in the heart in a patient with mitochondrial myopathy. 1934 65