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Successful cochlear implantation in a patient with mitochondrial hearing loss and m.625G>A transition

  • A Sudo (a1), N Takeichi (a2), K Hosoki (a3) and S Saitoh (a3)



We present a patient with mitochondrial hearing loss and a novel mitochondrial DNA transition, who underwent successful cochlear implantation.

Case report:

An 11-year-old girl showed epilepsy and progressive hearing loss. Despite the use of hearing aids, she gradually lost her remaining hearing ability. Laboratory data revealed elevated lactate levels, indicating mitochondrial dysfunction. Magnetic resonance imaging showed diffuse, mild brain atrophy. Cochlear implantation was performed, and the patient's hearing ability was markedly improved. Whole mitochondrial DNA genome analysis revealed a novel heteroplasmic mitochondrial 625G>A transition in the transfer RNA gene for phenylalanine. This transition was not detected in blood DNA from the patient's mother and healthy controls. Mitochondrial respiratory chain activities in muscle were predominantly decreased in complex III.


This case indicates that cochlear implantation can be a valuable therapeutic option for patients with mitochondrial syndromic hearing loss.


Corresponding author

Address for correspondence: Dr A Sudo, Department of Pediatrics, Sapporo City General Hospital, Kita 11, Nishi 13, Chuo-ku, Sapporo 060-8604, Japan Fax: +81 11 726 7912 E-mail:


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Abstract presented at the 9th Conference of the Japanese Society of Mitochondrial Research and Medicine, 18 December 2009, Tokyo, Japan



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1Sinnathuray, AR, Raut, V, Awa, A, Magee, A, Toner, JG. A review of cochlear implantation in mitochondrial sensorineural hearing loss. Otol Neurotol 2003;24:418–26
2Rahman, S, Blok, RB, Dahl, H-HM, Danks, DM, Kirby, DM, Chow, CW et al. Leigh syndrome: clinical features and biochemical and DNA abnormalities. Ann Neurol 1996;39:345–51
3Bernier, FP, Boneh, A, Dennett, X, Chow, CW, Cleary, MA, Thorburn, DR. Diagnostic criteria for respiratory chain disorders in adults and children. Neurology 2002;59:1406–11
4Rosenthal, EL, Kileny, PR, Boerst, A, Telian, SA. Successful cochlear implantation in a patient with MELAS syndrome. Am J Otol 1999;20:187–91
5Karkos, PD, Anari, S, Johnson, IJ. Cochlear implantation in patients with MELAS syndrome. Eur Arch Otorhinolaryngol 2005;262:322–4
6Sue, CM, Lipsett, LJ, Crimmins, DS, Tsang, CS, Boyages, SC, Presgrave, CM. Cochlear origin of hearing loss in MELAS syndrome. Ann Neurol 1998;43:350–9
7Yamasoba, T, Tsukuda, K, Oka, Y, Kobayashi, T, Kaga, K. Cochlear histopathology associated with mitochondrial transfer RNALeu(UUR) gene mutation. Neurology 1999;52:1705–7
8Yamasoba, T, Goto, Y-I, Komaki, H, Mimaki, M, Sudo, A, Suzuki, M. Cochlear damage due to germanium-induced mitochondrial dysfunction in guinea pigs. Neurosci Lett 2006;395:1822
9Papsin, BC, Gordon, KA. Cochlear implants for children with severe-to-profound hearing loss. N Engl J Med 2007;357:2380–7
10mtDNA Coding Region Sequence Polymorphism. In: [6 August 2011]
11Deschauer, M, Swalwell, H, Strauss, M, Zierz, S, Taylor, RW. Novel mitochondrial transfer RNA (Phe) gene mutation associated with late-onset neuromuscular disease. Arch Neurol 2006;63:902–5
12Mancuso, M, Filosto, M, Mootha, VK, Rocchi, A, Pistolesi, S, Murri, L. A novel mitochondrial tRNAPhe mutation causes MERRF syndrome. Neurology 2004;62:2119–21
13Konings, A, Van Camp, G, Goethals, A, Eyken, EV, Vandevelde, A, Azza, JB et al. Mutation analysis of mitochondrial DNA 12SrRNA and tRNASer(UCN) genes in non-syndromic hearing loss patients. Mitochondrion 2008;8:377–82
14Valente, L, Piga, D, Lamantea, E, Carrara, F, Uziel, G, Cudia, P et al. Identification of novel mutations in five patients with mitochondrial encephalomyopathy. Biochim Biophys Acta 2009;1787:491501
15Kleinle, S, Schneider, V, Moosmann, P, Brandner, S, Krähenbühl, S, Liechti-Gallati, S. A novel mitochondrial tRNAPhe mutation inhibiting anticodon stem formation associated with a muscle disease. Biochem Biophys Res Commun 1998;247:112–15
16Darin, N, Kollberg, G, Moslemi, AR, Tulinius, M, Holme, E, Grönlund, MA et al. Mitochondrial myopathy with exercise intolerance and retinal dystrophy in a sporadic patient with a G583A mutation in the mt tRNA(phe)gene. Neuromuscul Disord 2006;16:504–6


Successful cochlear implantation in a patient with mitochondrial hearing loss and m.625G>A transition

  • A Sudo (a1), N Takeichi (a2), K Hosoki (a3) and S Saitoh (a3)


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