No abstract available.
MELAS Syndrome*

No abstract available.
Biopsy ; MELAS Syndrome

No abstract available.
Biopsy ; MELAS Syndrome

Humans ; Stroke ; MELAS Syndrome

No abstract available.
Humans ; Intestinal Pseudo-Obstruction* ; MELAS Syndrome* ; Sepsis

OBJECTIVEMitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is a progressive, multisystem affected mitochondrial disease associated with a number of disease-related defective genes. MELAS has unpredictable presentations and clinical course, and it can be commonly misdiagnosed as encephalitis, cerebral infarction, or brain neoplasms. This review aimed to update the diagnosis progress in MELAS, which may provide better understanding of the disease nature and help make the right diagnosis as well.

DATA SOURCESThe data used in this review came from published peer review articles from October 1984 to October 2014, which were obtained from PubMed. The search term is "MELAS".

STUDY SELECTIONInformation selected from those reported studies is mainly based on the progress on clinical features, blood biochemistry, neuroimaging, muscle biopsy, and genetics in diagnosing MELAS.

RESULTSMELAS has a wide heterogeneity in genetics and clinical manifestations. The relationship between mutations and phenotypes remains unclear. Advanced serial functional magnetic resonance imaging (MRI) can provide directional information on this disease. Muscle biopsy has meaningful value in diagnosing MELAS, which shows the presence of ragged red fibers and mosaic appearance of cytochrome oxidase negative fibers. Genetic studies have reported that approximately 80% of MELAS cases are caused by the mutation m.3243A>G of the mitochondrial transfer RNA (Leu (UUR)) gene (MT-TL1).

CONCLUSIONSMELAS involves multiple systems with variable clinical symptoms and recurrent episodes. The prognosis of MELAS patients depends on timely diagnosis. Therefore, overall diagnosis of MELAS should be based on the maternal inheritance family history, clinical manifestation, and findings from serial MRI, muscle biopsy, and genetics.

Adult ; Dandy-Walker Syndrome ; complications ; pathology ; Humans ; MELAS Syndrome ; complications ; pathology ; Magnetic Resonance Imaging ; Male

Mitochondnal encephalomyopathies are multisysternic diseases affecting predominantly the CNS and skeletal muscLes by mitochondrial dysfunction. Mitochondrial diseases include three distinct syndromes: mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS): myoclonus epilepsy associated with ragged-red fibers (MERRF):and chronic progressive external ophthalmoplegia(CPEO). A characteristic abnormality called "ragged-red fibers" is usually seen on histochemical evaluation of muscle biopsy specimens in these diseases. The characteristic clinical presentations of MELAS are short stature, recurrent stroke like episodes, migraine-like headache, sensorineural hearmg loss, glucose intolerance and neuropathy. We now report a case of MELAS syndrome confirmed by demonstrating "ragged-red fibers" and abnormal mitochondria in muscle biopsy.
Biopsy ; Epilepsies, Myoclonic ; Glucose Intolerance ; Headache ; MELAS Syndrome* ; Mitochondria ; Mitochondrial Diseases ; Muscle, Skeletal ; Stroke

The mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is inherited maternally, in which the MTTL1*MELAS 3243 mutation has been most commonly found as a heteropla smy of A to G point mutation in the tRNALeu(UUR) gene. The MTTL1*MELAS 3271 mutation is known to be the second common mutation, though clinical features of both mutations are not remarkably different. Recently, a variety of minor mutations have been reported in patients with MELAS. In this study, major efforts have been made to investigate the allele frequency of major three mutations including MTTL1*MELAS 3243, 3252, 3271 in 10 Korean families with MELAS probands. The PCR and subsequent direct sequencing of the PCR product in the regions spanning these three mutation sites were employed to identify the mutation in each proband. All family members have been screened for the presence of these three mutations by PCR-RFLP assay using Apa I, Acc I and Bfr I restriction enzymes. The MTTL1*MELAS 3243 mutation was most commonly found (7 out of 10 families tested) followed by the MTTL1*MELAS 3271 which was identified in 1 out of 10 families. In the remaining 2 families none of three mutations were found, indicating the presence of either nuclear mutation or yet unidentified mitochondrial DNA mutation in these families.
Acidosis, Lactic* ; DNA, Mitochondrial ; Gene Frequency ; Humans ; MELAS Syndrome* ; Point Mutation ; Polymerase Chain Reaction ; Stroke*

Epileptic seizure is a frequent sign of mitochondrial encephalopathies with lactic acidosis and stroke-like episodes (MELAS). We report a 21-year-old woman with MELAS who had alternating hemispheric seizures. Her brain MRI showed migratory short lasting lesions. Serial EEG recordings revealed epileptiform discharges, which occurred first on the right frontotemporal region but then switched to the left frontotemporal region concordant to her clinical and MRI manifestations. Migratory short lasting lesions may be helpful features for differentiating MELAS syndrome from other epileptic syndromes.
Acidosis, Lactic ; Brain* ; Electroencephalography ; Epilepsy ; Female ; Humans ; Magnetic Resonance Imaging ; MELAS Syndrome* ; Seizures* ; Young Adult