Prevalence of mitochondrial gene mutations among hearing impaired patients.
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.
Usami
S
S
Department of Otorhinolaryngology, Hirosaki University School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan.
Abe
S
S
Akita
J
J
Namba
A
A
Shinkawa
H
H
Ishii
M
M
Iwasaki
S
S
Hoshino
T
T
Ito
J
J
Doi
K
K
Kubo
T
T
Nakagawa
T
T
Komiyama
S
S
Tono
T
T
Komune
S
S
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents / Q000009:adverse effects; D019929:Cochlear Implantation; D004272:DNA, Mitochondrial / Q000097:blood / Q000235:genetics*; D006319:Hearing Loss, Sensorineural / Q000139:chemically induced / Q000235:genetics* / Q000601:surgery; D006801:Humans; D007564:Japan; D017354:Point Mutation; D012150:Polymorphism, Restriction Fragment Length
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D004272:DNA, Mitochondrial