Skip Navigation

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Harding, A E
Right arrow Articles by Holt, I J
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Harding, A E
Right arrow Articles by Holt, I J
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

British Medical Bulletin 45:760-771 (1989)
© 1989 The British Council

research-article

Mitochondrial myopathies

A E Harding and I J Holt

Institute of Neurology Queen Square, London, UK

Abstract

The mitochondrial myopathies give rise to a diverse group of clinical syndromes, variably involving skeletal muscle and the central nervous system, with onset in childhood or adult life. In vitro studies of mitochondrial metabolism have identified a variety of functional defects of the respiratory chain, predominantly affecting complex I or complex III in adults, and complex IV in children. The increased incidence of maternal, as opposed to paternal, transmission in familial mitochondrial myopathy has led to the suggestion that these disorders may be caused by mutations of mitochondrail (mt) DNA. This hypothesis is derived from observations that mtDNA encodes subunits of the respiratory chain proteins and is exclusively maternally transmitted.

Analysis of muscle mtDNA shows two populations, one normal and the other deleted by up to nearly half its length, in about 40% of cases of mitochondrial myopathy. Only a single normal length population of mtDNA is seen in blood from these patients, and in blood and muscle from control subjects. Patients with mucle mtDNA deletions reported to date have all presented with progressive external ophthalmoplegia, including some with the Kearns-Sayre syndrome. They rarely have affected relatives. Deletions are not detected in cases of proximal myopathy alone, or those with adult onset syndromes predominantly affecting the central nervous system. There is no clear correlation between the deleted coding regions and the biochemical defects; even patients with seemingly identical muscle mtDNA deletions may be clinically and biochemically heterogeneous.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 ChestHome page
A. S. Clay, M. Behnia, and K. K. Brown
Mitochondrial Disease : A Pulmonary and Critical-Care Medicine Perspective
Chest, August 1, 2001; 120(2): 634 - 648.
[Abstract] [Full Text] [PDF]


Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.