Prevalence of mitochondrial gene mutations among hearing impaired patients

• Published in: Journal of medical genetics Vol. 37; no. 1; pp. 38 - 40
• Main Authors: Usami, Shin-ichi, Abe, Satoko, Akita, Jiro, Namba, Atsushi, Shinkawa, Hideichi, Ishii, Masanori, Iwasaki, Satoshi, Hoshino, Tomoyuki, Ito, Juichi, Doi, Katsumi, Kubo, Takeshi, Nakagawa, Takashi, Komiyama, Sohtaro, Tono, Tetsuya, Komune, Shizuo
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group Ltd 01-01-2000; BMJ; BMJ Publishing Group LTD; BMJ Group
• Subjects: Aminoglycosides; Anti-Bacterial Agents - adverse effects; Biological and medical sciences; Cochlear Implantation; Cochlear implants; DNA, Mitochondrial - blood; DNA, Mitochondrial - genetics; Ear, auditive nerve, cochleovestibular tract, facial nerve: diseases, semeiology; frequencies; hearing impairment; Hearing Loss, Sensorineural - chemically induced; Hearing Loss, Sensorineural - genetics; Hearing Loss, Sensorineural - surgery; Hearing protection; Humans; Japan; Medical sciences; mitochondria; Mitochondrial DNA; Mutation; Non tumoral diseases; Original; Otorhinolaryngology. Stomatology; Point Mutation; Polymorphism, Restriction Fragment Length; Japan; New Zealand; Human; Prevalence; Pathogenesis; Toxicity; Auditory disorder; Exploration; Mitochondrial DNA; Genetic determinism; Hearing loss; Gene frequency; Aminoglycoside; Point mutation; ENT disease
• ISSN: 0022-2593; 1468-6244; 1468-6244
• DOI: 10.1136/jmg.37.1.38

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.