Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0751651 (mitochondrial disease)
 1,844 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An out-of-frame mutation of the mitochondrial DNA-encoded subunit I of cytochrome c oxidase (COX) was discovered during investigation of a severe isolated muscle COX deficiency in a patient with motor neuron-like degeneration. The mutation is a heteroplasmic 5-bp microdeletion located in the 5' end of the COI gene, leading to premature termination of the corresponding translation product. Western blot analysis, immunohistochemistry, and single-fiber polymerase chain reaction demonstrated a tight correlation between COX defect, COX I expression, and percentage of mutation. COX subunits II, III, and IV were decreased as well, suggesting a defective assembly of COX holoenzyme. The mutation was associated with a clinical phenotype unusual for a mitochondrial disorder, that is, an isolated motor neuron disease (MND) with some atypical findings, including early onset, preferential involvement of the upper motor neuron, and increased cerebrospinal fluid protein content. MND may arise from impaired scavenging and overproduction of free oxygen radicals, a by-product of oxidative phosphorylation (OXPHOS). Our observation suggests that OXPHOS impairment could play a role in the pathogenesis of some MND cases.
 ...
PMID:Cytochrome c oxidase subunit I microdeletion in a patient with motor neuron disease. 945 Jul 76

Diagnosing mitochondrial disorder remains a challenge. In a 75-year-old women, with short stature, muscle cramps, ptosis, fasciculations and progressive, proximal limb weakness and wasting, hyponatriemia, abnormal lactate-stress-test, and slightly abnormal electromyography, muscle biopsy suggested granulomatous myositis. Corticosteroids and azathioprin were ineffective. After a second work-up amyotrophic-lateral-sclerosis was diagnosed. Riluzole was started, without effect. She developed respiratory insufficiency, requiring mechanical ventilation. Apical ballooning was found. After switching to non-invasive positive pressure ventilation and physiotherapy, she markedly improved. After a third diagnostic work-up, mitochondrial disorder was suspected. Unfortunately, she died suddenly from a cardiac arrhythmia at home. Mitochondrial disorder may mimic motor neuron disease, muscle biopsy may mimic myositis, and may show only little evidence for respiratory chain disorder.
 ...
PMID:Consequences of misdiagnosing mitochondrial disorder. 1686 Nov 55

Takotsubo syndrome may be associated with neuromuscular disorders, but has never been described in a patient with mitochondrial disorder. A 75-year-old woman developed muscle cramps, ptosis, fasciculations and slowly progressive weakness and wasting of all four limbs, starting 2.5 years earlier. After exclusion of various differential diagnoses, including non-specific granulomatous myositis, inclusion body myositis, and motor neuron disease, mitochondrial disorder was assumed. Muscle weakness progressed to respiratory insufficiency, requiring mechanical ventilation. Five days after intubation, she developed hypotension, torsades de pointes, ST-segment elevation, and negative T waves. Echocardiography revealed apical ballooning with akinesia of the left ventricular anteroseptal, apical, apicolateral and inferior segments. Coronary angiography was normal, and ventriculography confirmed apical hypokinesia and ballooning. Takotsubo syndrome was diagnosed, resolving completely within 7 weeks under bisoprolol. This case shows that Takotsubo syndrome occurs also in mitochondrial disorder and under mechanical ventilation, and may be triggered by stress from respiratory insufficiency, intubation, pain from tracheostomy, stress from mechanical ventilation, medication, or from the uncertain prognosis.
 ...
PMID:Apical ballooning (Takotsubo syndrome) in mitochondrial disorder during mechanical ventilation. 1788 29

Mitochondrial DNA instability disorders are responsible for a large clinical spectrum, among which amyotrophic lateral sclerosis-like symptoms and frontotemporal dementia are extremely rare. We report a large family with a late-onset phenotype including motor neuron disease, cognitive decline resembling frontotemporal dementia, cerebellar ataxia and myopathy. In all patients, muscle biopsy showed ragged-red and cytochrome c oxidase-negative fibres with combined respiratory chain deficiency and abnormal assembly of complex V. The multiple mitochondrial DNA deletions found in skeletal muscle revealed a mitochondrial DNA instability disorder. Patient fibroblasts present with respiratory chain deficiency, mitochondrial ultrastructural alterations and fragmentation of the mitochondrial network. Interestingly, expression of matrix-targeted photoactivatable GFP showed that mitochondrial fusion was not inhibited in patient fibroblasts. Using whole-exome sequencing we identified a missense mutation (c.176C>T; p.Ser59Leu) in the CHCHD10 gene that encodes a coiled-coil helix coiled-coil helix protein, whose function is unknown. We show that CHCHD10 is a mitochondrial protein located in the intermembrane space and enriched at cristae junctions. Overexpression of a CHCHD10 mutant allele in HeLa cells led to fragmentation of the mitochondrial network and ultrastructural major abnormalities including loss, disorganization and dilatation of cristae. The observation of a frontotemporal dementia-amyotrophic lateral sclerosis phenotype in a mitochondrial disease led us to analyse CHCHD10 in a cohort of 21 families with pathologically proven frontotemporal dementia-amyotrophic lateral sclerosis. We identified the same missense p.Ser59Leu mutation in one of these families. This work opens a novel field to explore the pathogenesis of the frontotemporal dementia-amyotrophic lateral sclerosis clinical spectrum by showing that mitochondrial disease may be at the origin of some of these phenotypes.
...
PMID:A mitochondrial origin for frontotemporal dementia and amyotrophic lateral sclerosis through CHCHD10 involvement. 2671 83

Background. The mutation 9185T>C in ATP6 gene, associated with Leigh syndrome, was reported in only few families. Motor neuron disease (MND), both clinically and electrophysiologically, was not previously described in association with this mutation. Case Report. 33-year-old male, with family history of mitochondrial disease, presented with cognitive impairment, exercise intolerance, and progressive muscle weakness. Examination revealed global hypotonia, and proximal tetraparesis, without atrophy or fasciculation, pyramidal signs, or sensory symptoms. The laboratory findings revealed an increase of lactate and lactate/pyruvate ratio; electromyogram showed chronic neurogenic compromise; muscle biopsy was suggestive of spinal muscular atrophy and mitochondriopathy; genetic study of SMN1 was negative but detected a homoplasmic mutation 9185T>C in ATP6 gene. His younger sister, with the same mutation, had cognitive impairment, ataxia, and muscle weakness. EMG showed axonal peripheral neuropathy. Conclusion. This case is unique because of the benignity and the coexistence of clinical, neurophysiological, and pathological findings suggestive of MND that, although described in mitochondrial disease, have not yet been reported in association with 9185T>C mutation. The present case contributes to the expansion of the phenotypic expressions of this particular mutation.
...
PMID:Motor Neuron Syndrome as a New Phenotypic Manifestation of Mutation 9185T>C in Gene MTATP6. 2554 92

Neuromuscular diseases are multifactorial pathologies characterized by extensive muscle fiber damage that leads to the activation of satellite cells and to the exhaustion of their pool, with consequent impairment of neurobiological aspects, such as cognition and motor control. To review the knowledge and obtain a broad view of the cognitive impairment on Neuromuscular Diseases. Cognitive impairment in neuromuscular disease was explored; a literature search up to October 2017 was conducted, including experimental studies, case reports and reviews written in English. Keywords included Cognitive Impairment, Neuromuscular Diseases, Motor Neuron Diseases, Dystrophinopathies and Mitochondrial Disorders. Several cognitive evaluation scales, neuroimaging scans, genetic analysis and laboratory applications in neuromuscular diseases, especially when it comes to the Motor Neuron Diseases, Dystrophinopathies and Mitochondrial Disorders. In addition, organisms model using rats in the genetic analysis and laboratory applications to verify the cognitive and neuromuscular impacts. Several studies indicate that congenital molecular alterations in neuromuscular diseases promote cognitive dysfunctions. Understanding these mechanisms may in the future guide the proper management of the patient, evaluation, establishment of prognosis, choice of treatment and development of innovative interventions such as gene therapy.
 ...
PMID:Cognitive impairment in neuromuscular diseases: A systematic review. 3006 88