Deletions of mitochondrial DNA in Kearns-Sayre syndrome and ocular myopathies: genetic, biochemical and morphological studies.

Abstract

Genetic, biochemical and morphological investigations were conducted on skeletal muscle mitochondria from 6 cases of ocular myopathy: 4 cases with Kearns-Sayre syndrome (KSS) and 2 with chronic progressive external ophthalmoplegia. All of these 6 cases showed mitochondrial DNA (mtDNA) deletions in addition to normal sized DNA in the quadriceps muscle. The deletions ranging from 3 to 8 kbp were also mapped between nucleotides 5500 and 16000 by Southern blot. The deleted genes encoded for some subunits of complexes I, IV, V and 5-10 tRNAS. The boundaries of the deletions have been sequenced in three patients. Five patients had mitochondrial respiratory chain deficiency in complex I as shown by the low oxygen consumption in isolated mitochondria using three NAD(+)-linked substrates. Mitochondria with an abnormal ultrastructure were also observed in 2 cases. A good relationship between the cytochrome c oxidase deficiency and the amount of deleted mtDNA was shown in our present investigations.

• Authors: F Degoul, I Nelson, P Lestienne, D Francois, N Romero, D Duboc, B Eymard, M Fardeau, G Ponsot, M Paturneau-Jouas
• Journal: Journal of the neurological sciences (J Neurol Sci) Vol. 101 Issue 2 Pg. 168-77 (Feb 1991) ISSN: 0022-510X [Print] Netherlands
• PMID: 1851820 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• DNA, Mitochondrial
• Multienzyme Complexes
• RNA, Transfer
• Electron Transport Complex IV

Topics

• Adult
• Base Sequence
• Blotting, Southern
• Chromosome Deletion
• Cytochrome-c Oxidase Deficiency
• DNA Mutational Analysis
• DNA, Mitochondrial (genetics)
• Electron Transport (genetics)
• Electron Transport Complex IV (genetics)
• Female
• Humans
• Kearns-Sayre Syndrome (genetics, pathology)
• Male
• Middle Aged
• Mitochondria, Muscle (metabolism, ultrastructure)
• Molecular Sequence Data
• Multienzyme Complexes (deficiency, genetics)
• Muscles (pathology)
• Ophthalmoplegia (genetics, pathology)
• Oxygen Consumption
• Polymerase Chain Reaction
• RNA, Transfer (genetics)