Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0013362 (dysarthria)
 3,768 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report four sporadic cases of cerebellar ataxia associated with hypogonadism. All patients were female. The neurological symptoms appeared in the first three decades. Apart from ataxia, the most frequent features were nystagmus, dysarthria, mental impairment, brisk tendon reflexes, skeletal deformities, peripheral neuropathy, and tremor. Neuroimaging studies showed constant cerebellar atrophy, in some instances associated with involvement of either grey or white cerebral matter. Neurophysiological studies demonstrated an axonal neuropathy. Endocrine evaluation showed heterogeneity of the hypogonadism, which was hypogonadotrophic in one patient and hypergonadotrophic in the other three. One patient had partial deficiency of muscle cytochrome c oxidase. The syndrome appears to be a heterogeneous multisystem disorder and in some cases a mitochondrial metabolism deficiency could be suspected.
 ...
PMID:Heterogeneous findings in four cases of cerebellar ataxia associated with hypogonadism (Holmes' type ataxia). 845 11

Sixteen members of a family with a history of autosomal dominant progressive external ophthalmoplegia (adPEO) with hypogonadism were examined. The muscular involvement commenced cranially and descended in relation to increasing disease duration. The neuromuscular signs were PEO, dysarthria, dysphonia, limb muscle weakness with wasting, absence of Achilles tendon reflexes, and distal vibration sensory loss. The electromyogram (EMG) was myopathic in facial and proximal limb muscles. Neurogenic involvement was suspected in a few tibial anterior muscles. Neurography showed signs of axonal neuropathy correlated to clinical signs. F-responses were reduced in number or absent in peroneal nerves, and did not correlate to clinical signs or disease duration. Muscle biopsies in advanced cases had structural abnormalities of mitochondria, ragged-red fibers, and focal cytochrome c oxidase deficiency. A combination of muscle-nerve involvement with PEO, Achilles tendon areflexia, distal vibration sensory impairment, myopathic EMG, and abnormally low sural nerve responses seems to be typical of this type of mitochondrial disorder.
 ...
PMID:Muscle-nerve involvement in autosomal dominant progressive external ophthalmoplegia with hypogonadism. 860 26

Leigh disease is a subacute neurodegenerative disorder characterized by symmetric necrotic lesions in the basal ganglia, cerebellum, thalamus, brain stem, and optical nerves and caused by altered oxidative phosphorylation. We describe the clinical, biochemical, neuroimaging, and molecular studies of a 19-year-old boy with early-onset Leigh disease manifesting as severe extrapyramidal disorder with generalized dystonia and choreoathetosis. He was born of healthy parents after an uneventful pregnancy and delivery. At the age of 2 1/2 years, after a minor respiratory infection, he developed unstable, broad-based gait and tremor of the hands. These symptoms persisted for the next several years, when ataxia became more prominent. Difficulty in swallowing, dysarthria, trunk dystonia, and marked dyskinesia of the arms and hands gradually developed. Nystagmus, transient ptosis, and strabismus also appeared. Abnormal laboratory findings included elevated plasma and cerebrospinal fluid lactate and pyruvate, with an abnormal lactate/pyruvate ratio. Cranial computed tomography and magnetic resonance imaging demonstrated signs of cerebellar atrophy, bilateral and symmetric hypodensities in the lentiform nucleus and thalamus, and transient hyperintensities of cerebral peduncles in T2-weighted sequences suggestive of Leigh disease. Muscle biopsy revealed isolated fiber atrophy, necrotic fibers undergoing phagocytosis, and no ragged-red fibers. The measured catalytic activity of cytochrome c oxidase in skeletal muscle homogenates demonstrated a partial cytochrome c oxidase deficiency No abnormalities in the mitochondrial genome and in the SURF-1 gene were found. The boy is currently receiving levodopa therapy, creatine monohydrate, and a high dosage of thiamine and lipoic acid, his condition is stabilized, and extrapyramidal symptoms are less pronounced.
 ...
PMID:Cytochrome c oxidase partial deficiency-associated Leigh disease presenting as an extrapyramidal syndrome. 1151 Sep 39

A 30-year-old man was hospitalized with dysarthria and weakness of his right arm and leg. Three months previously, he had noticed numbness and weakness of his right shoulder, which spread to involve his left leg but which improved after 8 months. On admission, neurological examination revealed limb kinetic apraxia and constructive apraxia of the right hand, motor aphasia, dysarthria, and spastic quadriplegia. Sensory examination revealed hyperalgesia and dysesthesia in the right arm and left leg. Deep tendon reflexes were hyperactive in all four extremities. And he had bilateral Babinski signs. Laboratory examination revealed pH 7.38, PCO2 46.1 Torr, PO2 93.4 Torr, BE 1.7, and blood lactate, 9.0 mg/dl (normal 5-20 mg/dl). Cerebrospinal fluid lactate level was 20.0 mg/dl. pyruvate 1.34 mg/dl. and protein 83 mg/dl. Blood lactate and pyruvate values were markedly elevated after aerobic exercise. T2WI brain MRI showed scattered high signal lesions in the left precentral and postcentral gyrus, right paracentral lobes, both superior frontal gyri, and right superior temporal gyrus. Right biceps brachi biopsy showed almost complete cytochrome c oxidase (COX) deficiency. There were no ragged-red fibers. There was marked decrease of COX activity: 2.7 nmol/min/mg-mitochondrial protein (normal range: 33.0 +/- 16.1, n = 7) in the biopsied muscle. Open brain biopsy (after permission from the patient and his family) revealed gliosis and perivascular infiltration of lymphocytes and macrophages without vascular proliferation. There was no mitochondrial DNA mutations, deletion or duplication, including tRNA-Leu 3243, 8993, 3271, 9176, 3291, and tRNA-Lys 8344, 8356, and 8363. From these findings, a diagnosis of COX deficiency presenting as MELAS-like episodes was done. His mother also showed abnormality on aerobic exercise test, but she had no episode of stroke or neurological dysfunction. Six months later, his aphasia and apraxia of the right hand had resolved, and at discharge he was able to ambulate with a cane. Ten months later, he returned to his work. There has been no recurrence of neurologic symptoms over the next 3 years and 10 months. This patient appears to represent a rare case of adult onset COX deficiency presenting as MELAS-like episodes.
 ...
PMID:[MELAS-like episodes in an adult case with cytochrome c oxidase deficiency]. 1523 72

Mutations in POLG gene are responsible for a wide spectrum of clinical disorders with altered mitochondrial DNA (mtDNA) integrity, including mtDNA multiple deletions and depletion. Sensory ataxic neuropathy with ophthalmoparesis (SANDO) caused by mutations in POLG gene, fulfilling the clinical triad of sensory ataxic neuropathy, dysarthria and/or dysphagia and ophthalmoparesis, has described in a few reports. Here we described five cases of adult onset autosomal recessive sensory ataxic neuropathy with ophthalmoplegia. All patients had ataxia, neuropathy, myopathy, and progressive external ophthalmoplegia (PEO). The muscle pathology revealed ragged-red and cytochrome c oxidase (COX) negative fibers in three patients. However, deficiencies in the activities of mitochondrial respiratory chain enzyme complexes were not detected in any of the patients' muscle samples. Multiple deletions of mtDNA were detected in blood and muscle specimens but mtDNA depletion was not found. Due to these diagnostic difficulties, POLG-related syndromes are definitively diagnosed based on the presence of deleterious mutations in the POLG gene.
 ...
PMID:Sensory ataxic neuropathy with ophthalmoparesis caused by POLG mutations. 1858 14

Chronic progressive external ophthalmoplegia is one of mitochondrial disorders, characterized by ptosis, limitation of eye movement, variably severe bulbar muscle weakness and proximal limb weakness. Chronic progressive external ophthalmoplegia complicated with acquired disease is extremely rare. We report a 44 years old male patient with more than 20 years of chronic progressive bilateral ptosis and limitation of eye movements manifested dysarthria, dysphagia and neck muscle weakness for 3 years. The first muscle biopsy showed red-ragged fibers and cytochrome c oxidase negative fibers as well as inflammatory cells infiltration. Electron microscopy revealed paracrystalline inclusions. Mitochondrial genetic analysis demonstrated a large-scale mtDNA deletion of m.8470_13446del4977. The patient was treated with prednisone. In a three-year follow-up study, the second biopsy was performed. Before the treatment, except bilateral ptosis and external ophthalmopelgia, this patient presented bulbar muscle weakness and neck muscle weakness. After treated with prednisone, the symptoms of dysphagia, dysarthria and neck muscle weakness were significantly improved, and the second biopsy showed only mitochondrial myopathy pathology but the inflammations disappeared. Here, we report a patient with chronic progressive external ophthalmoplegia complicated with inflammatory myopathy and after treated with prednisone as myositis, he had a significant therapeutic effect.
 ...
PMID:Chronic progressive external ophthalmoplegia with inflammatory myopathy. 2567 60

Chronic progressive external ophthalmoplegia (CPEO) is common in mitochondrial disorders and is frequently associated with multiple mtDNA deletions. The onset is typically in adulthood, and affected subjects can also present with general muscle weakness. The underlying genetic defects comprise autosomal-dominant or recessive mutations in several nuclear genes, most of which play a role in mtDNA replication. Next-generation sequencing led to the identification of compound-heterozygous RNASEH1 mutations in two singleton subjects and a homozygous mutation in four siblings. RNASEH1, encoding ribonuclease H1 (RNase H1), is an endonuclease that is present in both the nucleus and mitochondria and digests the RNA component of RNA-DNA hybrids. Unlike mitochondria, the nucleus harbors a second ribonuclease (RNase H2). All affected individuals first presented with CPEO and exercise intolerance in their twenties, and these were followed by muscle weakness, dysphagia, and spino-cerebellar signs with impaired gait coordination, dysmetria, and dysarthria. Ragged-red and cytochrome c oxidase (COX)-negative fibers, together with impaired activity of various mitochondrial respiratory chain complexes, were observed in muscle biopsies of affected subjects. Western blot analysis showed the virtual absence of RNase H1 in total lysate from mutant fibroblasts. By an in vitro assay, we demonstrated that altered RNase H1 has a reduced capability to remove the RNA from RNA-DNA hybrids, confirming their pathogenic role. Given that an increasing amount of evidence indicates the presence of RNA primers during mtDNA replication, this result might also explain the accumulation of mtDNA deletions and underscores the importance of RNase H1 for mtDNA maintenance.
 ...
PMID:RNASEH1 Mutations Impair mtDNA Replication and Cause Adult-Onset Mitochondrial Encephalomyopathy. 2609 73

Troyer syndrome is an autosomal recessive form of hereditary spastic paraplegia (HSP) caused by deleterious mutations in the SPG20 gene. Although the disease is associated with a loss of function mechanism of spartin, the protein encoded by SPG20, the precise pathogenesis is yet to be elucidated. Recent data indicated an important role for spartin in both mitochondrial maintenance and function. Here we report a child presenting with progressive spastic paraparesis, generalized muscle weakness, dysarthria, impaired growth, and severe isolated decrease in muscle cytochrome c oxidase (COX) activity. Whole exome sequencing identified the homozygous c.988A>G variant in SPG20 gene (p.Met330Val) resulting in almost complete loss of spartin in skeletal muscle. Further analyses demonstrated significant tissue specific reduction of COX 4, a nuclear encoded subunit of COX, in muscle suggesting a role for spartin in proper mitochondrial respiratory chain function mediated by COX activity. Our findings need to be verified in other Troyer syndrome patients in order to classify it as a form of HSP caused by mitochondrial dysfunction.
 ...
PMID:Novel Homozygous Missense Mutation in SPG20 Gene Results in Troyer Syndrome Associated with Mitochondrial Cytochrome c Oxidase Deficiency. 2753 78