According to the recently published reports about mitochondrial diseasbl the clinical manifestations are more various than expected. There have been no clinical studies covering whole spectrum of mitochond7iral disease except a few case reports in our country. The authors performed this studies to understand the various clinical and laboratory findings of mitochondrial disease and the usefulness of current tools for the diagnosis of mitochondrial diseases. We reviewed retrospectively the clinical, laboratory and pathologic findings of mitochondrial disease. The diagnosis of mitochondrial disease was based on clinical manifestations, 'ragged-red fiber' in Gomori stainging, and/or abnormal mitochondrial morphologies on electron microscopy. Twenty one patients were diagnosed as mitochondrial disease. Their clinical diagnosis included 7 MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes); 3 MERRF (myoclonic epilepsy with ragged red fibers); 2 KSS (Kearns-Sayre syndrome); 7 CPEO (chronic progressive external ophthalmoplegia); and 2 mitochondrial myopathy. The usefulness of electrodiagnostic studies, such as EMG, NCV and FEG, were limited in some patients. The muscle biopsy showed ragged red fibers in 10 of 15 sampled examined. Eleven patients had abnormal serum lactic acid level. The authors found that the mitochondrial disease revealed broad clinical spectrum and clinically available diagnostic tests, such as serum lactate and light microscopic examination showed limited value. Therefore, to evaluate the mitochondrial dysfunction with systemic involvement may be desirable to depend on sensitive and specific methods including succinate dehydrogenase (SDH) staining, electron microscopy and biologic studies of mitochondrial DNA.
Acidosis, Lactic ; Biopsy ; Diagnosis ; Diagnostic Tests, Routine ; DNA, Mitochondrial ; Epilepsy ; Humans ; Lactic Acid ; MELAS Syndrome ; MERRF Syndrome ; Microscopy, Electron ; Mitochondrial Diseases* ; Mitochondrial Myopathies ; Muscular Diseases ; Ophthalmoplegia, Chronic Progressive External ; Retrospective Studies ; Succinate Dehydrogenase

Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is one of the mitochondrial disorders that can present as a stroke-like episode or seizure. Although the pathophysiology of MELAS remains inconclusive, the main possibilities are thus far thought to be mitochondrial cytopathy and angiopathy. This case report describes a 61-year-old woman diagnosed with MELAS who presented simultaneously with vascular hyperemia and crossed cerebellar diaschisis.
Acidosis, Lactic ; Female ; Humans ; Hyperemia ; Kearns-Sayre Syndrome ; Mitochondrial Diseases ; Mitochondrial Encephalomyopathies ; Mitochondrial Myopathies ; Seizures

Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is one of the mitochondrial disorders that can present as a stroke-like episode or seizure. Although the pathophysiology of MELAS remains inconclusive, the main possibilities are thus far thought to be mitochondrial cytopathy and angiopathy. This case report describes a 61-year-old woman diagnosed with MELAS who presented simultaneously with vascular hyperemia and crossed cerebellar diaschisis.
Acidosis, Lactic ; Female ; Humans ; Hyperemia ; Kearns-Sayre Syndrome ; Mitochondrial Diseases ; Mitochondrial Encephalomyopathies ; Mitochondrial Myopathies ; Seizures

Mitochondrion is an intracellular organelle with its own genome. Its function in cellular metabolism is indispensable that mitochondrial dysfunction gives rise to multisystemic failure. The manifestation is most prominent with tissues of high energy demand such as muscle and nerve. Mitochondrial myopathies occur not only by mutations in mitochondrial genome, but also by defects in nuclear genes or secondarily by toxic insult on mitochondrial replication. Currently curative treatment modality does not exist and symptomatic treatment remains mainstay. Administration of L-arginine holds great promise according to the recent reports. Advances in mitochondrial RNA import might enable a new therapeutic strategy.
Arginine ; Genome ; Genome, Mitochondrial ; MELAS Syndrome ; MERRF Syndrome ; Mitochondria ; Mitochondrial Myopathies ; Muscles ; Ophthalmoplegia, Chronic Progressive External ; Organelles ; RNA

OBJECTIVETo explore the application value of next generation sequencing (NGS) in the diagnosis of mitochondrial disorders.

METHODAccording to mitochondrial disease criteria, genomic DNA was extracted using standard procedure from peripheral venous blood of patients with suspected mitochondrial disease collected from neurological department of Beijing Children's Hospital Affiliated to Capital Medical University between October 2012 and February 2014. Targeted NGS to capture and sequence the entire mtDNA and exons of the 1 000 nuclear genes related to mitochondrial structure and function. Clinical data were collected from patients diagnosed at a molecular level, then clinical features and the relationship between genotype and phenotype were analyzed.

RESULTMutation was detected in 21 of 70 patients with suspected mitochondrial disease, in whom 10 harbored mtDNA mutation, while 11 nuclear DNA (nDNA) mutation. In 21 patients, 1 was diagnosed congenital myasthenic syndrome with episodic apnea due to CHAT gene p.I187T homozygous mutation, and 20 were diagnosed mitochondrial disease, in which 10 were Leigh syndrome, 4 were mitochondrial encephalomyopathy with lactic acidosis and stroke like episodes syndrome, 3 were Leber hereditary optic neuropathy (LHON) and LHON plus, 2 were mitochondrial DNA depletion syndrome and 1 was unknown. All the mtDNA mutations were point mutations, which contained A3243G, G3460A, G11778A, T14484C, T14502C and T14487C. Ten mitochondrial disease patients harbored homozygous or compound heterozygous mutations in 5 genes previously shown to cause disease: SURF1, PDHA1, NDUFV1, SUCLA2 and SUCLG1, which had 14 mutations, and 7 of the 14 mutations have not been reported.

CONCLUSIONNGS has a certain application value in the diagnosis of mitochondrial diseases, especially in Leigh syndrome atypical mitochondrial syndrome and rare mitochondrial disorders.

Child ; DNA, Mitochondrial ; genetics ; High-Throughput Nucleotide Sequencing ; Homozygote ; Humans ; Leigh Disease ; Mitochondrial Diseases ; diagnosis ; Mitochondrial Encephalomyopathies ; Mutation ; Optic Atrophy, Hereditary, Leber ; Phenotype ; Point Mutation ; Sequence Analysis, DNA

Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is one of the classic mitochondrial diseases characterized by symptoms of repeated episodes of hemiparesis with mitochondrial DNA mutation. We report a rare case of early onset MELAS patient confirmed by genetic analysis with Wolff-Parkinson-White syndrome.
Acidosis, Lactic ; DNA, Mitochondrial ; Humans ; MELAS Syndrome ; Mitochondrial Diseases ; Mitochondrial Encephalomyopathies ; Mitochondrial Myopathies ; Paresis ; Wolff-Parkinson-White Syndrome

MELAS is a mitochondrial respiratory chain disorder characterized by progressive neurodegeneration associated with stroke-like episode, increased plasma lactate levels and distinctive findings on neuroimaging studies. Hence we onset of right-sided hemiplegia accompanied by lactic acidosis and CT-Scan findings of diffuse hypodensity of the cerebral white matter at the time of the stroke-like episode. The diagnosis was confirmed by mutation analysis on blood and hair which showed the typical mtDNA A3243G mutation. This is the first local report of a confirmed case of MELAS.
Human ; Female ; Child Preschool ; MELAS SYNDROME ; MUSCULOSKELETAL DISEASES ; MUSCULAR DISEASES ; MITOCHONDRIAL MYOPATHIES ; MITOCHONDRIAL ENCEPHALOMYOPATHIES

PURPOSE:The study was carried out to characterized the clinical and the laboratorial features of children with mitochondrial respiratoy chain disorders in Korea. METHODS:We retrospectively analyzed the clinical and the loboratorial data of 28 children with significantly low activities in respiratory chain complexes of muscle using spectrophotometry. RESULTS:The mean age was 6.67+/-4.44 years and the ratio males to female was 1.15:1. Eighteen patients (64.3%) showed defects in Complex I, 8 (28.6%) in Complex VI, 1 (3.6%) in Complex II, and 1 in Complex I and IV. Eight cases (28.6%) were diagnosed with Leigh disease, one with MELAS, Kearns-Sayre syndrome, and Alpers disease retrospectively, but the predominant clinical presentations were a nonspecific encephalopathy (17/28, 60.7%). Epilepsy was seen in 21 (75.0%) patients, while developmental delay in 27 (96.4%) patients. Fifteen out of 28 children (53.6%), clinical symptoms mostly appeared below age of 1 year. The brain MRI showed diffuse cortical atrophy in 18 (64.3%) patients and basal ganglia signal changes in 12 (42.9%) patients. CONCLUSION:The defects in mitochondrial respiratory chain complexes should be considered in any children with an unexplained neurological condition including even epilepsy.
Atrophy ; Basal Ganglia ; Brain ; Child* ; Diffuse Cerebral Sclerosis of Schilder ; Electron Transport* ; Epilepsy ; Female ; Humans ; Kearns-Sayre Syndrome ; Korea ; Leigh Disease ; Magnetic Resonance Imaging ; Male ; MELAS Syndrome ; Mitochondrial Diseases ; Retrospective Studies ; Spectrophotometry

External ophthalmoplegia and ptosis are common manifestations of mitochondrial cytopathy, such as chronic progressive external ophthalmoplegia (CPEO). However, these symptoms and signs may also be presenting features of myasthenia gravis (MG). There are a few reports of CPEO with elevated acetylcholine receptor antibody (AchR-Ab). We report a case of AD-type CPEO with elevated acetylcholine receptor binding antibody. We confirmed a mutation on the SLC25A4 gene by molecular analysis.
Acetylcholine ; Kearns-Sayre Syndrome ; Mitochondrial Myopathies ; Myasthenia Gravis ; Ophthalmoplegia ; Ophthalmoplegia, Chronic Progressive External

Blepharoptosis is a common indication for surgery in plastic surgery units, yet its possible underlying pathology frequently remains unidentified. A 52-year-old man with a 20-year history of progressive bilateral ptosis (right>left) presented with recurrent ptosis of both eyes; he had undergone an operation on the levator aponeurosis 12 years prior. Due to the suspicion of an underlying disease, he was evaluated further. Chronic progressive external ophthalmoplegia in transition to the more severe syndromic variant Kearns-Sayre syndrome, a mitochondrial disorder causing myopathy, was diagnosed. The patient was treated with coenzyme Q10, and he underwent ptosis surgery on both eyes. This case illustrates a potentially multi-systemic disease that was diagnosed by a further evaluation of a common symptom, in this case worsening blepharoptosis. Awareness of myopathic symptoms is necessary to prevent overlooking serious yet improvable conditions.
Blepharoplasty ; Blepharoptosis* ; Humans ; Kearns-Sayre Syndrome* ; Middle Aged ; Mitochondrial Diseases ; Muscular Diseases ; Ophthalmoplegia, Chronic Progressive External ; Pathology ; Surgery, Plastic