Prevalence of mitochondrial gene mutations among hearing impaired patients
- Shin-ichi Usamia,
- Satoko Abea,
- Jiro Akitaa,
- Atsushi Nambaa,
- Hideichi Shinkawaa,
- Masanori Ishiib,
- Satoshi Iwasakic,
- Tomoyuki Hoshinoc,
- Juichi Itod,
- Katsumi Doie,
- Takeshi Kuboe,
- Takashi Nakagawaf,
- Sohtaro Komiyamaf,
- Tetsuya Tonog,
- Shizuo Komuneg
- aDepartment of Otorhinolaryngology, Hirosaki University School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan, bDepartment of Otorhinolaryngology, Tokyo Kosei Nenkin Hospital, Tokyo 162, Japan, cDepartment of Otorhinolaryngology, Hamamatsu University School of Medicine, Hamamatsu 431-31, Japan, dDepartment of Otolaryngology, Otsu Red Cross Hospital, Otsu 520, Japan, eDepartment of Otolaryngology, Osaka University Faculty of Medicine, Suita 565-0871, Japan, fDepartment of Otorhinolaryngology, Faculty of Medicine, Kyushu University, Fukuoka 812-8582, Japan, gDepartment of Otorhinolaryngology, Miyazaki Medical College, Miyazaki 889-16, Japan
- Professor Usami, Department of Otorhinolaryngology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan
- Revised 16 August 1999
- Accepted 27 August 1999
Abstract
The frequency of three mitochondrial point mutations, 1555A→G, 3243A→G, and 7445A→G, known to be associated with hearing impairment, was examined using restriction fragment length polymorphism (RFLP) analysis in two Japanese groups: (1) 319 unrelated SNHL outpatients (including 21 with aminoglycoside antibiotic injection history), and (2) 140 cochlear implantation patients (including 22 with aminoglycoside induced hearing loss). Approximately 3% of the outpatients and 10% of the cochlear implantation patients had the 1555A→G mutation. The frequency was higher in the patients with a history of aminoglycoside injection (outpatient group 33%, cochlear implantation group 59%). One outpatient (0.314%) had the 3243A→G mutation, but no outpatients had the 7445A→G mutation and neither were found in the cochlear implantation group. The significance of the 1555A→G mutation, the most prevalent mitochondrial mutation found in this study of a hearing impaired population in Japan, among subjects with specific backgrounds, such as aminoglycoside induced hearing loss, is evident.
