GTR Home > Conditions/Phenotypes > Autosomal dominant progressive external ophthalmoplegia with mitochondrial DNA deletions 2


Progressive external ophthalmoplegia is characterized by multiple mitochondrial DNA deletions in skeletal muscle. The most common clinical features include adult onset of weakness of the external eye muscles and exercise intolerance. Both autosomal dominant and autosomal recessive inheritance can occur; autosomal recessive inheritance is usually more severe (Filosto et al., 2003; Luoma et al., 2004). PEO caused by mutations in the POLG gene are associated with more complicated phenotypes than those forms caused by mutations in the ANT1 or C10ORF2 genes (Lamantea et al., 2002). For a general phenotypic description and a discussion of genetic heterogeneity of autosomal dominant progressive external ophthalmoplegia, see PEOA1 (157640). [from OMIM]

Associated genes

  • Also known as: 1, AAC1, ANT, ANT 1, ANT1, MTDPS12, PEO2, PEO3, T1, SLC25A4
    Summary: solute carrier family 25 (mitochondrial carrier; adenine nucleotide translocator), member 4

Clinical features

  • Generalized muscle weakness
  • Ragged-red muscle fibers
  • Multiple mitochondrial DNA deletions
  • Sensorineural hearing impairment
  • Ptosis
  • Progressive external ophthalmoplegia
  • EMG: myopathic abnormalities
  • Exercise intolerance
  • Subsarcolemmal accumulations of abnormally shaped mitochondria
  • Decreased activity of cytochrome C oxidase in muscle tissue
  • Facial palsy
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