Current classification of mitochondrial disorders
Child; Humans; Adult; Mutation; Animals; adolescent; DNA; Mitochondrial/genetics; Mitochondrial Diseases/classification/genetics
2003
Andreu AL; DiMauro S
Journal Of Neurology
2003
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Journal Article
<a href="http://doi.org/10.1007/s00415-003-0281-3" target="_blank" rel="noreferrer">10.1007/s00415-003-0281-3</a>
Prevalence and progression of mitochondrial diseases: a study of 50 patients
Female; Humans; Male; Adult; Aged; Middle Aged; Disease Progression; Survival Analysis; Phenotype; adolescent; IM; Age of Onset; Electromyography; Chronic Progressive External/ep [Epidemiology]; Chronic Progressive External/ge [Genetics]; Chronic Progressive External/pa [Pathology]; DNA; Epilepsies; Lactic Acid/bl [Blood]; MELAS Syndrome/ep [Epidemiology]; MELAS Syndrome/ge [Genetics]; MELAS Syndrome/pa [Pathology]; Mitochondrial Diseases/ep [Epidemiology]; Mitochondrial Diseases/ge [Genetics]; Mitochondrial Diseases/pa [Pathology]; Mitochondrial/ge [Genetics]; Muscle; Myoclonic/ep [Epidemiology]; Myoclonic/ge [Genetics]; Myoclonic/pa [Pathology]; Neural Conduction/ph [Physiology]; Ophthalmoplegia; Skeletal/pa [Pathology]; Spain/ep [Epidemiology]
We report 50 patients with various clinical phenotypes of mitochondrial disease studied over the past 10 years in a large urban area (Madrid Health Area 5). The clinical phenotypes showed a large variety of abnormalities in molecular biology and biochemistry. The prevalence of mitochondrial diseases was found to be 5.7 per 100,000 in the population over 14 years of age. Clinical and electrophysiological assessment reveal signs of neuropathy in 10 patients. Electromyographic findings consistent with myopathy were obtained in 37 cases. Six patients died of medical complications. Disease phenotype influenced survival to some degree (P < 0.01). Age of onset and gender were not associated with differences in survival. Mitochondrial disease is thus far more common than expected and a common cause of chronic morbidity.
2003
Arpa J; Cruz-Martinez A; Campos Y; Gutierrez-Molina M; Garcia-Rio F; Perez-Conde C; Martin MA; Rubio JC; Del Hoyo P; Arpa-Fernandez A; Arenas J
Muscle & Nerve
2003
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Journal Article
<a href="http://doi.org/10.1002/mus.10507" target="_blank" rel="noreferrer">10.1002/mus.10507</a>
Retrospective, multicentric study of 180 children with cytochrome C oxidase deficiency
Child; Female; Humans; infant; Male; Prognosis; Mutation; adolescent; Preschool; infant; Q3 Literature Search; Newborn; DNA; Mitochondrial/genetics; Proteins/genetics; Sequence Deletion; Membrane Proteins; Mitochondrial Proteins; Carrier Proteins; Cytochrome-c Oxidase Deficiency/diagnosis/genetics/mortality; Czech Republic; Poland; Slovakia
A retrospective, multicenter study of 180 children with cytochrome c oxidase (COX) deficiency analyzed the clinical features, prognosis, and molecular bases of the COX deficiency. Clinical symptoms including failure to thrive, encephalopathy, hypotony, Leigh syndrome, cardiac involvement, and hepatopathy appeared in most patients early after birth or in early childhood. Two thirds of all children died. Biochemical examination revealed an isolated COX deficiency in 101 children and COX deficiency combined with disturbances of other respiratory chain complexes in 79 children. Blood and cerebrospinal fluid lactate increased in 85% and 81% of examined cases, respectively. Pathogenic mutations in mitochondrial or nuclear DNA were established in 75 patients. Mutations in surfeit locus protein 1 gene (SURF1) were found in 47 children with Leigh syndrome; 2bp deletion 845-846delCT was found in 89% of independent alleles. Mutations in a mitochondrial copper-binding protein (SCO2) gene were found in nine children with encephalomyopathy and/or cardiomyopathy; all of them were homozygotes or heterozygotes for 1541G>A mutation. Different mitochondrial DNA (mtDNA) deletion or depletion were found in nine children, mtDNA mutation 3243A>G in six, mtDNA mutation 8363G>A in two children with Leigh syndrome and mtDNA mutations 8344A>G, and 9205-9206delTA in one child each. COX deficiency represents a heterogeneous group of diseases with unfavorable prognosis. Marked prevalence of two nuclear DNA mutations (845-846delCT in the SURF1 gene and 1541G>A in the SCO2 gene) associated with COX deficiency in a Slavonic population suggests the existence of regional differences in the genetic basis of COX deficiency.
2006
Bohm M; Pronicka E; Karczmarewicz E; Pronicki M; Piekutowska-Abramczuk D; Sykut-Cegielska J; Mierzewska H; Hansikova H; Vesela K; Tesarova M; Houstkova H; Houstek J; Zeman J
Pediatric Research
2006
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Journal Article
<a href="http://doi.org/10.1203/01.pdr.0000190572.68191.13" target="_blank" rel="noreferrer">10.1203/01.pdr.0000190572.68191.13</a>
Long-term outcome and clinical spectrum of 73 pediatric patients with mitochondrial diseases
Child; Female; Humans; infant; Male; Cohort Studies; Follow-Up Studies; Severity of Illness Index; Survival Analysis; Longitudinal Studies; Probability; Time Factors; Proportional Hazards Models; Preschool; infant; Q3 Literature Search; Newborn; AIM; IM; retrospective studies; cause of death; DNA; Mitochondrial Diseases/ge [Genetics]; Mitochondrial/ge [Genetics]; MELAS Syndrome/di [Diagnosis]; Mitochondrial Encephalomyopathies/di [Diagnosis]; DNA Fragmentation; HEREDITARY; Leber/di [Diagnosis]; Leber/ge [Genetics]; Leber/mo [Mortality]; MELAS Syndrome/mo [Mortality]; MELAS Syndrome/th [Therapy]; Mitochondrial Diseases/di [Diagnosis]; Mitochondrial Diseases/mo [Mortality]; Mitochondrial Encephalomyopathies/mo [Mortality]; Mitochondrial Encephalomyopathies/th [Therapy]; Mitochondrial Myopathies/di [Diagnosis]; Mitochondrial Myopathies/ge [Genetics]; Mitochondrial Myopathies/mo [Mortality]; Optic Atrophy
OBJECTIVES: We sought to determine the clinical spectrum, survival, and long-term functional outcome of a cohort of pediatric patients with mitochondrial diseases and to identify prognostic factors. METHODS: Medical charts were reviewed for 73 children diagnosed between 1985 and 2005. The functional status of living patients was assessed prospectively by using the standardized Functional Independence Measure scales. RESULTS: Patients fell into 7 phenotypic categories: neonatal-onset lactic acidosis (10%), Leigh syndrome (18%), nonspecific encephalopathy (32%), mitochondrial (encephalo)myopathy (19%), intermittent neurologic (5%), visceral (11%), and Leber hereditary optic neuropathy (5%). Age at first symptoms ranged from prenatal to 16 years (median: 7 months). Neurologic symptoms were the most common (90%). Visceral involvement was observed in 29% of the patients. A biochemical or molecular diagnosis was identified for 81% of the patients as follows: deficiency of complex IV (27%), of pyruvate dehydrogenase or complex I (25% each), of multiple complexes (13%), and of pyruvate carboxylase (5%) or complexes II+III (5%). A mitochondrial DNA mutation was found in 20% of patients. At present, 46% of patients have died (median age: 13 months), 80% of whom were 5 years (n = 32), 62% had Functional Independence Measure quotients of >0.75. CONCLUSIONS: Mitochondrial diseases in children span a wide range of symptoms and severities. Age at first symptoms is the strongest predictor mortality. Despite a high mortality rate in the cohort, 62% of patients aged >5 years have only mild impairment or normal functional outcome.
2007
Debray FG; Lambert M; Chevalier I; Robitaille Y; Decarie JC; Shoubridge EA; Robinson BH; Mitchell GA
Pediatrics
2007
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Journal Article
<a href="http://doi.org/10.1542/peds.2006-1866" target="_blank" rel="noreferrer">10.1542/peds.2006-1866</a>
Clinical phenotype, prognosis and mitochondrial DNA mutation load in mitochondrial encephalomyopathies
Child; Female; Humans; Male; Adult; Prognosis; Mutation; adolescent; Q3 Literature Search; DNA; Muscle; Mitochondrial Encephalomyopathies/diagnosis/etiology/genetics; Mitochondrial/genetics; Skeletal/pathology
We studied 42 individuals, including 8 patients with either complete or partial syndrome of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS), 8 patients with either complete or partial syndrome of myoclonic epilepsy with ragged-red fibers (MERRF) and 26 maternal family members who carried either the A3243G or A8344G mutation of mitochondrial DNA (mtDNA). Clinical manifestations and prognosis were followed up in the patients harboring the A3243G or A8344G mutation. The relationship between clinical features and proportions of mutant mtDNAs in muscle biopsies, blood cells and/or hair follicles was studied. In the 8 regularly followed patients with the A3243G mutation, 4 died within 1 month to 7 years due to status epilepticus and/or recurrent stroke-like episodes. Two patients developed marked mental deterioration and 2 remained stationary. All of the patients harboring the A8344G mutation were stable or deteriorated slightly, except for 1 patient who died due to brain herniation after putaminal hemorrhage. The A3243G and A8344G mtDNA mutations were heteroplasmic in the muscle biopsies, blood cells and hair follicles of both the probands and their maternal family members. The mean proportion of A3243G mutant mtDNA in the muscle biopsies of the patients with MELAS syndrome (68.5 +/- 21.3%, range 33-92%) was significantly higher than that of the asymptomatic family members (37.1 +/- 12.6%, range 0-51%). The average proportions of A8344G mutant mtDNA in the muscle biopsies (90.1 +/- 3.9%, range 89-95%) and hair follicles (93.9 +/- 6.4%, range 84-99%) of the patients with MERRF syndrome were also significantly higher than those of the asymptomatic family members (muscle: 40.3 +/- 39.5%, range 1-80%; hair follicles: 51.0 +/- 44.5%, range 0.1-82%). We concluded that measurement of the proportion of mutant mtDNA in muscle biopsies may provide useful information in the identification of symptomatic patients with mitochondrial encephalomyopathies. For patients with the A3243G mutation, the prognosis was related to status epilepticus and the number of recurrent stroke-like episodes and was much worse than for patients with the A8344G mutation of mtDNA, who had stable or slowly deteriorating clinical courses.
2002
Huang CC; Kuo HC; Chu CC; Liou CW; Ma YS; Wei YH
Journal Of Biomedical Science
2002
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Journal Article
<a href="http://doi.org/10.1007/bf02254979" target="_blank" rel="noreferrer">10.1007/bf02254979</a>
Mitochondrial neurogastrointestinal encephalomyopathy: diagnosis by rectal biopsy
Female; Humans; adolescent; Q3 Literature Search; Electron; Microscopy; Muscles/pathology; DNA; Biopsy/methods; Intestinal Pseudo-Obstruction/pathology; Mitochondrial Myopathies/pathology; Mitochondrial/analysis; Rectum/innervation/pathology
A 14-year-old girl with the mitochondrial neurogastrointestinal encephalopathy syndrome had an 8-year history of intestinal pseudoobstruction with abdominal pain, persistent vomiting, gastric and duodenal dilatation, and duodenal diverticulosis. The child appeared chronically malnourished and had severe growth failure. Multisystem involvement was evident with the presence of ptosis, external ophthalmoplegia, muscle wasting, peripheral neuropathy, and diffuse white matter disease seen on magnetic resonance imaging. Lactic acidosis and increased cerebrospinal fluid protein were observed. Mitochondrial enzyme analysis of fresh-frozen skeletal muscle revealed a respiratory chain defect. Molecular genetic studies showed multiple mitochondrial DNA deletions. Pathologic findings in the intestine included atrophy of the external layer of the muscularis propria and an increased number of abnormal-appearing mitochondria in ganglion and smooth-muscle cells. Microvesicular steatosis was observed in liver, skeletal, and gastrointestinal smooth muscle, and Schwann cells of peripheral nerve. Brightly eosinophilic inclusions in the cytoplasm of gastrointestinal ganglion cells were visible by light microscopy, which were confirmed to be megamitochondria by ultrastructural studies. This is the first report of abnormal mitochondria observed in intestinal ganglion and smooth-muscle cells in this syndrome.
1998
Perez-Atayde AR; Fox V; Teitelbaum JE; Anthony DA; Fadic R; Kalsner L; Rivkin M; Johns DR; Cox GF
The American Journal Of Surgical Pathology
1998
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Journal Article
<a href="http://doi.org/10.1097/00000478-199809000-00014" target="_blank" rel="noreferrer">10.1097/00000478-199809000-00014</a>
Clinical spectrum, morbidity, and mortality in 113 pediatric patients with mitochondrial disease
Child; Female; Humans; infant; Male; Mutation; Survival Analysis; adolescent; Preschool; Non-U.S. Gov't; Research Support; infant; Newborn; retrospective studies; Age of Onset; DNA; Cardiomyopathies/etiology/mortality; Electron Transport; Electron Transport Chain Complex Proteins/deficiency; Mitochondrial; Mitochondrial Diseases/complications/genetics/mortality; Neuromuscular Diseases/etiology/mortality
OBJECTIVES: The aim of this study was to elucidate the frequency of major clinical manifestations in children with mitochondrial disease and establish their clinical course, prognosis, and rates of survival depending on their clinical features. METHODS: We performed a retrospective review of the medical records of 400 patients who were referred for evaluation of mitochondrial disease. By use of the modified Walker criteria, only patients who were assigned a definite diagnosis were included in the study. RESULTS: A total of 113 pediatric patients with mitochondrial disease were identified. A total of 102 (90%) patients underwent a muscle biopsy as part of the diagnostic workup. A significant respiratory chain (RC) defect, according to the diagnostic criteria, was found in 71% of the patients who were evaluated. In this cohort, complex I deficiency (32%) and combined complex I, III, and IV deficiencies (26%) were the most common causes of RC defects, followed by complex IV (19%), complex III (16%), and complex II deficiencies (7%). Pathogenic mitochondrial DNA abnormalities were found in 11.5% of the patients. A substantial fraction (40%) of patients with mitochondrial disorders exhibited cardiac disease, diagnosed by Doppler echocardiography; however, the majority (60%) of patients had predominant neuromuscular manifestations. No correlation between the type of RC defect and the clinical presentation was observed. Overall, the mean age at presentation was 40 months. However, the mean age at presentation was 33 months in the cardiac group and 44 months in the noncardiac group. Twenty-six (58%) patients in the cardiac group exhibited hypertrophic cardiomyopathy, 29% had dilated cardiomyopathy, and the remainder (13%) had left ventricular noncompaction. Patients with cardiomyopathy had an 18% survival rate at 16 years of age. Patients with neuromuscular features but no cardiomyopathy had a 95% survival at the same age. CONCLUSIONS: This study gives strong support to the view that in patients with RC defects, cardiomyopathy is more common than previously thought and tends to follow a different and more severe clinical course. Although with a greater frequency than previously reported, mitochondrial DNA mutations were found in a minority of patients, emphasizing that most mitochondrial disorders of childhood follow a Mendelian pattern of inheritance.
2004
Scaglia F; Towbin JA; Craigen WJ; Belmont JW; Smith EO; Neish SR; Ware SM; Hunter JV; Fernbach SD; Vladutiu GD; Wong LJ; Vogel H
Pediatrics
2004
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Journal Article
<a href="http://doi.org/10.1542/peds.2004-0718" target="_blank" rel="noreferrer">10.1542/peds.2004-0718</a>
Resting muscle pain as the first clinical symptom in children carrying the MTTK A8344G mutation
Child; Female; Humans; Adult; Mutation; adolescent; Q3 Literature Search; DNA Mutational Analysis; Pedigree; DNA; Mitochondrial/genetics; MERRF Syndrome/complications/genetics/physiopathology; Muscular Diseases/etiology/genetics/physiopathology; Pain/etiology/genetics/physiopathology; Polymerase Chain Reaction
The characteristic clinical presentation, especially the appearance of muscle symptoms, is quite unique in children carrying the mtA8344G mutation. The diagnosis of MERRF syndrome is seldom made in the pediatric age. Fatigue is a common finding in children of pubertal age. Fatigue in combination with recurrent resting muscle pain occurs frequently in the initial phase of various hereditary muscle disorders and in several autoimmune, endocrine and metabolic syndromes. In the absence of obvious biochemical/metabolic abnormalities and in the lack of neurological symptoms the complaints are frequently labelled as fibromyalgia or chronic fatigue syndrome. In patients with behavioural or psychiatric abnormalities one might even start to question the organic etiology of the complaints. We describe a family carrying the classic MTTK mutation with a variable degree of heteroplasmy, presenting in childhood as isolated recurrent muscle pain as the first symptom of the disease.
2007
van de Glind G; de Vries M; Rodenburg R; Hol F; Smeitink JA; Morava E
European Journal Of Paediatric Neurology
2007
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Journal Article
<a href="http://doi.org/10.1016/j.ejpn.2007.01.004" target="_blank" rel="noreferrer">10.1016/j.ejpn.2007.01.004</a>
Mitochondrial disorders
Child; Humans; Adult; Mutation; DNA; Mitochondrial/genetics; DNA/genetics; Electron Transport/genetics; Gene Rearrangement/genetics; Mitochondrial Diseases/genetics/therapy; Oxidative Phosphorylation; Point Mutation/genetics; Proteins/genetics
In the medical literature the term 'mitochondrial disorders' is to a large extent applied to the clinical syndromes associated with abnormalities of the common final pathway of mitochondrial energy metabolism, i.e. oxidative phosphorylation (OXPHOS). Faulty oxidative phosphorylation may be due to overall dysfunction of the respiratory chain, a heteromultimeric structure embedded in the inner mitochondrial membrane, or can be associated with single or multiple defects of the five complexes forming the respiratory chain itself. From the genetic standpoint, the respiratory chain is a unique structure of the inner mitochondrial membrane formed by means of the complementation of two separate genetic systems: the nuclear genome and the mitochondrial genome. The nuclear genome encodes the large majority of the protein subunits of the respiratory complexes and most of the mitochondrial DNA (mtDNA) replication and expression systems, whereas the mitochondrial genome encodes only 13 respiratory complex subunits, and some RNA components of the mitochondrial translational apparatus. Accordingly, mitochondrial disorders due to defects in OXPHOS include both mendelian-inherited and cytoplasmic-inherited diseases. This review describes human genetic diseases associated with mtDNA and nuclear DNA mutations leading to impaired OXPHOS.
Zeviani M; Di Donato S
Brain
2004
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Journal Article
<a href="http://doi.org/10.1093/brain/awh259" target="_blank" rel="noreferrer">10.1093/brain/awh259</a>