title: Successful cochlear implantation in a patient with mitochondrial hearing loss and m.625G>A transition.
abstract: OBJECTIVE
  We present a patient with mitochondrial hearing loss and a novel mitochondrial DNA transition, who underwent successful cochlear implantation.
  
  
  METHODS
  An 11-year-old girl showed epilepsy and progressive hearing loss. Despite the use of hearing aids, she gradually lost her remaining hearing ability. Laboratory data revealed elevated lactate levels, indicating mitochondrial dysfunction. Magnetic resonance imaging showed diffuse, mild brain atrophy. Cochlear implantation was performed, and the patient's hearing ability was markedly improved. Whole mitochondrial DNA genome analysis revealed a novel heteroplasmic mitochondrial 625G>A transition in the transfer RNA gene for phenylalanine. This transition was not detected in blood DNA from the patient's mother and healthy controls. Mitochondrial respiratory chain activities in muscle were predominantly decreased in complex III.
  
  
  CONCLUSIONS
  This case indicates that cochlear implantation can be a valuable therapeutic option for patients with mitochondrial syndromic hearing loss.
authors.affiliation: Department of Pediatrics, Sapporo City General Hospital, Sapporo, Japan. akira.sudo@doc.city.sapporo.jp
authors.forename: A
authors.initials: A
authors.lastname: Sudo
authors.forename: N
authors.initials: N
authors.lastname: Takeichi
authors.forename: K
authors.initials: K
authors.lastname: Hosoki
authors.forename: S
authors.initials: S
authors.lastname: Saitoh
mesh_terms: D001301:Audiometry, Pure-Tone; D001921:Brain / Q000473:pathology; D002648:Child; D019929:Cochlear Implantation; D014450:Electron Transport Complex III; D004829:Epilepsy, Generalized / Q000150:complications; D005260:Female; D054629:Genome, Mitochondrial / Q000235:genetics; D006130:Growth Disorders / Q000150:complications; D006319:Hearing Loss, Sensorineural / Q000150:complications / Q000235:genetics / Q000601:surgery*; D006801:Humans; D006983:Hypertrichosis / Q000150:complications; D007773:Lactates / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D008928:Mitochondria / Q000235:genetics*; D028361:Mitochondrial Diseases / Q000235:genetics* / Q000503:physiopathology / Q000601:surgery; D010649:Phenylalanine / Q000235:genetics; D017354:Point Mutation / Q000235:genetics*; D012343:RNA, Transfer / Q000235:genetics; D016896:Treatment Outcome
chemical_list: D007773:Lactates; D010649:Phenylalanine; D012343:RNA, Transfer; D014450:Electron Transport Complex III