Novel mitochondrial DNA mutations responsible for maternally inherited nonsyndromic hearing loss

Hum Mutat. 2012 Apr;33(4):681-9. doi: 10.1002/humu.22023. Epub 2012 Feb 14.


Some cases of maternally inherited isolated deafness are caused by mtDNA mutations, frequently following an exposure to aminoglycosides. Two mitochondrial genes have been clearly described as being affected by mutations responsible for this pathology: the ribosomal RNA 12S gene and the transfer RNA serine (UCN) gene. A previous study identified several candidate novel mtDNA mutations, localized in a variety of mitochondrial genes, found in patients with no previous treatment with aminoglycosides. Five of these candidate mutations are characterized in the present study. These mutations are localized in subunit ND1 of complex I of the respiratory chain (m.3388C>A [p.MT-ND1:Leu28Met]), the tRNA for Isoleucine (m.4295A>G), subunit COII of complex IV (m.8078G>A [p.MT-CO2:Val165Ile]), the tRNA of Serine 2 (AGU/C) (m.12236G>A), and Cytochrome B, subunit of complex III (m.15077G>A [p.MT-CYB:Glu111Lys]). Cybrid cell lines have been constructed for each of the studied mtDNA mutations and functional studies have been performed to assess the possible consequences of these mutations on mitochondrial bioenergetics. This study shows that a variety of mitochondrial genes, including protein-coding genes, can be responsible for nonsyndromic deafness, and that exposure to aminoglycosides is not required to develop the disease, giving new insights on the molecular bases of this pathology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aminoglycosides / adverse effects
  • Cell Line
  • Cell Respiration / genetics
  • Cytochromes b / genetics
  • Cytochromes b / metabolism
  • DNA, Mitochondrial*
  • Female
  • Hearing Loss / chemically induced
  • Hearing Loss / genetics*
  • Humans
  • Male
  • Mitochondria / genetics
  • Mitochondria / metabolism
  • Mothers
  • Mutation*
  • NADH Dehydrogenase / chemistry
  • NADH Dehydrogenase / genetics*
  • NADH Dehydrogenase / metabolism
  • Pedigree
  • Phosphorylation
  • Polymorphism, Restriction Fragment Length
  • Protein Conformation
  • RNA, Transfer, Ile / genetics
  • RNA, Transfer, Ser / genetics*
  • RNA, Transfer, Ser / metabolism


  • Aminoglycosides
  • DNA, Mitochondrial
  • RNA, Transfer, Ile
  • RNA, Transfer, Ser
  • Cytochromes b
  • NADH Dehydrogenase
  • NADH dehydrogenase subunit 1, human