Different Clinical Characteristics of Aminoglycoside-Induced Profound Deafness with and without the 1555 A→G Mitochondrial MutationTono T. · Kiyomizu K. · Matsuda K. · Komune S. · Usami S. · Abe S. · Shinkawa H.
aDepartment of Otorhinolaryngology, Miyazaki Medical College, Miyazaki, bDepartment of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, and cDepartment of Otorhinolaryngology, Hirosaki University School of Medicine, Hirosaki, Japan
Recent genetic studies have shown that hereditary susceptibility to aminoglycoside antibiotics is caused by the 1555 A→G mitochondrial mutation. We found the 1555 mutation in 4 out of 68 postlingual deaf patients who were candidates for cochlear implantation. All 4 patients developed bilateral profound hearing loss following administration of aminoglycosides. The pedigree of the family shows exclusively maternal transmission of hearing impairment in each case. On comparison with neuro-otological findings from aminoglycoside-induced deaf patients without the 1555 mutation, four distinct characteristics were noted: (1) a progressive nature of hearing loss; (2) better residual pure-tone thresholds; (3) lower thresholds for electrical promontory stimulation, and (4) well-preserved vestibular function. Although other factors such as differing dosages and/or administration routes may also be involved, profound hearing loss associated with the 1555 mutation may be due to a different pathogenic mechanism, i.e., strial dysfunction rather than a direct insult to the hair cells.
Department of Otorhinolaryngology, Miyazaki Medical College
5200 Kihara Kiyotake, Miyazaki 889-1601 (Japan)
Tel. +81 985 85 2966, Fax +81 985 85 7029
Received: Received: November 19, 1999
Accepted after revision: May 22, 2000
Number of Print Pages : 6
Number of Figures : 3, Number of Tables : 2, Number of References : 15
ORL (Journal for Oto-Rhino-Laryngology and Its Related Specialties)
Founded 1938 as ‘Practica Oto-Rhino-Laryngologica’ by J. Berberich and E. Schlittler, continued by L. Rüedi 1947–1970, E. Huizinga 1948–1970, C.R. Pfaltz 1968–1984
Vol. 63, No. 1, Year 2001 (Cover Date: January-February 2001)
Journal Editor: W. Arnold, München
ISSN: 0301–1569 (print), 1423–0275 (Online)
For additional information: http://www.karger.com/journals/orl