Mitochondrial encephalomyopathies: biochemical approach.

Abstract

Thanks to recent advances in the molecular genetics of mitochondrial encephalomyopathies, we can now begin to correlate genetic lesions with biochemical defects. In the fatal infantile myopathy due to cytochrome c oxidase (COX) deficiency, an autosomal recessive condition, immunocytochemical studies have shown an isolated defect of subunit VIIa, which is 1 of the only 2 tissue-specific subunits of human COX. In muscle biopsies from patients with Kearns-Sayre syndrome, a multisystem disorder characterized by deletions of the mitochondrial DNA (mtDNA), the activities of all mitochondrial enzymes containing mtDNA-encoded subunits are decreased. The results of Northern analysis, in situ hybridization, and immunocytochemistry in muscle, and of mitochondrial protein synthesis in cultured fibroblasts suggest that partially deleted mtDNAs are transcribed but not translated, probably due to lack of indispensable tRNAs.

• Authors: S Dimauro, C T Moraes, S Shanske, A Lombes, H Nakase, S Mita, H J Tritschler, E Bonilla, A F Miranda, E A Schon
• Journal: Revue neurologique (Rev Neurol (Paris)) Vol. 147 Issue 6-7 Pg. 443-9 ( 1991) ISSN: 0035-3787 [Print] France
• PMID: 1660180 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S., Review)

Chemical References

• DNA, Mitochondrial
• Electron Transport Complex IV

Topics

• Brain Diseases (complications, genetics)
• Cytochrome-c Oxidase Deficiency
• DNA, Mitochondrial (genetics)
• Electron Transport Complex IV (genetics)
• Genes, Recessive (genetics)
• Humans
• Mitochondria, Muscle (physiology)
• Muscular Diseases (complications, genetics)