title: Immunohistochemical and ultrastructural abnormalities in muscle from a patient with sensorineural hearing loss related to a 1555 A-to-G mitochondrial mutation.
abstract: Genetic studies indicate that hereditary susceptibility of the inner ear to aminoglycoside antibiotic toxicity is caused by a nucleotide 1555 A-to-G mutation in the mitochondrial 12S rRNA gene. Although the phenotype associated with this mutation is nonsyndromic hearing loss, the possibility remains that there could be effects on other tissues that, like the inner ear, contain numerous mitochondria, particularly muscle. We obtained a temporalis muscle specimen from a deaf patient with the A1555G mutation and found informative pathologic features, including mosaic activity of cytochrome c oxidase immunoreactivity and mitochondrial ultrastructure. These findings suggest that mitochondrial dysfunction from the A1555G mutation extends beyond the inner ear.
authors.affiliation: Department of Otolaryngology, Shiga University of Medical Science, Tsukinowa-cho, Seta, Otsu 520 2192, Japan. hkohzaki@belle.shiga-med.ac.jp
authors.forename: Hideaki
authors.initials: H
authors.lastname: Kouzaki
authors.forename: Mikio
authors.initials: M
authors.lastname: Suzuki
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shimizu
mesh_terms: D003576:Electron Transport Complex IV / Q000235:genetics* / Q000378:metabolism; D006319:Hearing Loss, Sensorineural / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008928:Mitochondria / Q000201:enzymology* / Q000235:genetics / Q000648:ultrastructure; D018656:Muscle Fibers, Fast-Twitch / Q000201:enzymology* / Q000648:ultrastructure; D018482:Muscle, Skeletal / Q000201:enzymology / Q000648:ultrastructure*; D009154:Mutation; D020641:Polymorphism, Single Nucleotide; D012335:RNA, Ribosomal / Q000235:genetics*
chemical_list: D012335:RNA, Ribosomal; C075526:RNA, ribosomal, 12S; D003576:Electron Transport Complex IV