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

Senataxin recently was identified as the mutated gene in ataxia-oculomotor apraxia 2, which is characterized by ataxia, oculomotor apraxia, and increased alpha-fetoprotein levels. In this study, we evaluated 24 ataxic patients from 10 French-Canadian families. All cases have a homogeneous phenotype consisting of a progressive ataxia appearing between 2 and 20 (mean age, 14.8) years of age with associated dysarthria, saccadic ocular pursuit, distal amyotrophy, sensory and motor neuropathy, and increased alpha-fetoprotein levels but absence of oculomotor apraxia. Linkage disequilibrium was observed with markers in the ataxia-oculomotor apraxia 2 locus on chromosome 9q34. We have identified four mutations in senataxin in the French-Canadian population including two novel missense mutations: the 5927T-->G mutation changes the leucine encoded by codon 1976 to an arginine in the helicase domain (L1976R), and the 193G-->A mutation changes a glutamic acid encoded by codon 65 into a lysine in the N-terminal domain of the protein (E65K). The common L1976R mutation is shared by 17 of 20 (85%) carrier chromosomes. The study of this large French-Canadian cohort better defines the phenotype of this ataxia and presents two novel mutations in senataxin including the more common founder mutation in the French-Canadian population.
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PMID:Mutations in senataxin responsible for Quebec cluster of ataxia with neuropathy. 1573 1

Sensory ataxia with neuropathy, dysarthria and ophthalmoparesis represent the clinical triad of SANDO, a specific mitochondrial phenotype first reported in 1997 in association with multiple mitochondrial DNA deletions and mutations in POLG1 or more rarely in the C10orf2 (twinkle-helicase) gene. We report a 44-year-old man with SANDO who harboured two novel mutations (P648R/R807C) in the POLG1 gene.
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PMID:SANDO: two novel mutations in POLG1 gene. 1691 51

Progressive external ophthalmoplegia (PEO) can be caused by a disorder characterized by multiple mitochondrial DNA (mtDNA) deletions due to mutations in the TWINKLE gene, encoding a mtDNA helicase. We describe a 71-year-old woman who had developed PEO at age 55 years. She had cataracts, diabetes, paresthesias, cognitive defects, memory problems, hearing loss, and sensory ataxia. She had muscle weakness with ragged red fibers on biopsy. MRI showed static white matter changes. A c.908G>A substitution (p.R303Q) in the TWINKLE gene was identified. Multiple mtDNA deletions were detected in muscle but not blood by a PCR-based method, but not by Southern blot analysis. MtDNA copy number was maintained in blood and muscle. A systematic literature search was used to identify the genotypic and phenotypic spectrum of dominant TWINKLE-related disease. Patients were adults with PEO and symptoms including myopathy, neuropathy, dysarthria or dysphagia, sensory ataxia, and parkinsonism. Diabetes, cataract, memory loss, hearing loss, and cardiac problems were infrequent. All reported mutations clustered between amino acids 303 and 508 with no mutations at the N-terminal half of the gene. The TWINKLE gene should be analyzed in adults with PEO even in the absence of mtDNA deletions in muscle on Southern blot analysis, and of a family history for PEO. The pathogenic mutations identified 5' beyond the linker region suggest a functional role for this part of the protein despite the absence of a primase function in humans. In our patient, the pathogenesis involved multiple mtDNA deletions without reduction in mtDNA copy number.
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PMID:Finding twinkle in the eyes of a 71-year-old lady: a case report and review of the genotypic and phenotypic spectrum of TWINKLE-related dominant disease. 1935 76