Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0013421 (dystonia)
 8,418 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Leigh syndrome (LS) is the clinical prototype of a genetically-determined mitochondrial encephalopathy. Twenty-two of 34 patients with LS had evidence of a movement disorder (MD). Dystonia, the most common MD, was present in 19 cases, rigidity in 4, tremor in 2, chorea in 2, hypokinesia in 2, myoclonus in 1, and tics in 1. Dystonia was most commonly multifocal at onset and showed progression in six patients. In half of the cases an enzymatic defect was detected, most commonly cytochrome C oxidase. The neuroradiologic findings showed prominent basal ganglia lesions in 20/21 patients. Putamen, caudate, substantia nigra and globus pallidus were involved in this order of frequency. This experience was reflected in a literature review encompassing 284 cases of LS. However, only 26.4% had MD. Eleven patients, including one of our cases, presented as the primary torsion dystonia phenotype. There are clinical and pathological similarities between LS and other metabolic diseases affecting the central nervous system. The enhanced vulnerability of the nervous system to metabolic stress and the resemblance in the distribution of the pathology of these diverse conditions suggests a common pathogenetic mechanism. An excitotoxin-mediated mechanism is favored, one which might account for the frequent involvement of the basal ganglia in LS.
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PMID:Disorders of movement in Leigh syndrome. 839 42

We present a boy of eight years of age with symptoms of Kearns-Sayre syndrome (KSS) characterised by ophthalmoparesis, palpebral ptosis, mitochondrial myopathy, pigmentous retinitis, associated to short stature, cerebellar signs, cardiac blockade, diabetes mellitus, elevated cerebrospinal fluid protein concentration, and focal hand and foot dystonia. The skeletal muscle biopsy demonstrated ragged red fibers, cytochrome C oxidase-negative and succinate dehydrogenase-positive fibers. The magnetic resonance imaging showed symmetrical signal alteration in tegmentum of brain stem, pallidum and thalamus. Mitochondrial DNA analysis from skeletal muscle showed a deletion in heteroplasmic condition. The association of dystonia to KSS, confirmed by molecular analysis, is first described in this case, and the importance of oxidative phosphorylation defects in the physiopathogenesis of this type of movement disorder is stressed.
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PMID:Kearns-Sayre syndrome "plus". Classical clinical findings and dystonia. 1068 96

Defects in mitochondrial cytochrome c oxidase or respiratory chain complex IV (CIV) assembly are a frequent cause of human mitochondrial disorders. Specifically, mutations in four conserved assembly factors impinging the biogenesis of the mitochondrion-encoded catalytic core subunit 2 (COX2) result in myopathies. These factors afford stability of newly synthesized COX2 (the dystonia-ataxia syndrome protein COX20), a protein with two transmembrane domains, and maturation of its copper center, CuA (cardiomyopathy proteins SCO1, SCO2, and COA6). COX18 is an additional COX2 assembly factor that belongs to the Oxa1 family of membrane protein insertases. Here, we used a gene-editing approach to generate a human COX18 knock-out HEK293T cell line that displays isolated complete CIV deficiency. We demonstrate that COX20 stabilizes COX2 during insertion of its N-proximal transmembrane domain, and subsequently, COX18 transiently interacts with COX2 to promote translocation across the inner membrane of the COX2 C-tail that contains the apo-CuA site. The release of COX18 from this complex coincides with the binding of the SCO1-SCO2-COA6 copper metallation module to COX2-COX20 to finalize COX2 biogenesis. Therefore, COX18 is a new candidate when screening for mitochondrial disorders associated with isolated CIV deficiency.
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PMID:Human mitochondrial cytochrome c oxidase assembly factor COX18 acts transiently as a membrane insertase within the subunit 2 maturation module. 2833 Aug 71