Abstract
The authors describe a novel pathogenic G5540A transition in the mitochondrial transfer RNA (tRNA)Trp gene of a sporadic encephalomyopathy characterized by spinocerebellar ataxia. Clinical features also included neurosensorial deafness, peripheral neuropathy, and dementia. Biochemistry revealed a severe reduction of cytochrome c oxidase (COX) activity. Single-fiber PCR demonstrated higher levels of mutant genomes in COX-negative ragged red fibers than in normal fibers. These findings confirm that COX is more susceptible than other respiratory chain complexes to mutations in the mitochondrial tRNATrp gene.
Publication types
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Case Reports
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Research Support, Non-U.S. Gov't
MeSH terms
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Adult
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Biopsy
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Cytochrome-c Oxidase Deficiency*
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DNA Mutational Analysis
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DNA, Mitochondrial / genetics*
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Dementia / etiology
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Disease Progression
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Fatal Outcome
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Female
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Hearing Loss, Sensorineural / etiology
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Humans
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Mitochondria, Muscle / enzymology
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Mitochondria, Muscle / pathology
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Mitochondrial Encephalomyopathies / complications
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Mitochondrial Encephalomyopathies / diagnosis*
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Mitochondrial Encephalomyopathies / genetics*
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Muscle, Skeletal / enzymology
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Muscle, Skeletal / pathology
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Point Mutation / genetics*
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RNA, Transfer, Trp / genetics*
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Spinocerebellar Ataxias / etiology
Substances
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DNA, Mitochondrial
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RNA, Transfer, Trp