Hearing loss with a mitochondrial gene mutation is highly prevalent in Japan

Laryngoscope. 1999 Feb;109(2 Pt 1):334-8. doi: 10.1097/00005537-199902000-00029.


Objectives/hypothesis: Mutations in the mitochondrial genome may predispose people to sensorineural hearing loss. An adenine to guanine point mutation in the tRNA(Leu(UUR)) gene at nucleotide 3,243 is one of the deaf-related mutations. This mutation is reported to be associated with 0.9% of diabetes mellitus patients. However, the prevalence of this mutation in hearing-impaired patients still remains unknown. The aim of this study was to determine the prevalence of this mutation among bilaterally sensorineural hearing-impaired patients in Japan.

Study design: Retrospective survey of 100 patients with bilateral sensorineural hearing loss without any evident causes.

Methods: Mitochondrial DNA fragments from the patients were amplified by polymerase chain reaction, followed by a restriction enzyme fragment length polymorphism method.

Results: Three patients with this mutation were identified. Their clinical profiles were different from the category which had been considered as hearing loss caused by this mitochondrial gene mutation.

Conclusions: The mutation is associated with approximately 3% of bilateral sensorineural hearing loss cases of unknown origin and is possibly distributed widely in sensorineural hearing-impaired patients in Japan.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Age of Onset
  • Audiometry, Pure-Tone / methods
  • Child
  • DNA Mutational Analysis
  • DNA Restriction Enzymes / genetics
  • DNA, Mitochondrial / genetics*
  • Female
  • Hearing Loss, Bilateral / diagnosis
  • Hearing Loss, Bilateral / ethnology*
  • Hearing Loss, Bilateral / genetics*
  • Hearing Loss, Sensorineural / diagnosis
  • Hearing Loss, Sensorineural / ethnology*
  • Hearing Loss, Sensorineural / genetics*
  • Humans
  • Japan / epidemiology
  • Male
  • Middle Aged
  • Point Mutation / genetics*
  • Polymerase Chain Reaction
  • Polymorphism, Restriction Fragment Length
  • Prevalence
  • RNA, Transfer, Leu / genetics*
  • Retrospective Studies


  • DNA, Mitochondrial
  • RNA, Transfer, Leu
  • DNA Restriction Enzymes