Association of myopathy with large-scale mitochondrial DNA duplications and deletions: which is pathogenic? uri icon

Overview

abstract

  • We identified large-scale heteroplasmic mitochondrial DNA (mtDNA) rearrangements in a 50-year-old woman with an adult-onset progressive myopathy. The predominant mtDNA abnormality was a 21.2-kb duplicated molecule. In addition, a small population of the corresponding partially deleted 4.6-kb molecule was detected. Skeletal muscle histology revealed fibers that were negative for cytochrome c oxidase (COX) activity and had reduced mtDNA-encoded COX subunits. By single-fiber polymerase chain reaction analysis, COX-negative fibers contained a low number of wild-type or duplicated mtDNA molecules (ie, nondeleted). In situ hybridization demonstrated that the abnormal fibers contained increased amounts of mtDNA compared with normal fibers and that most of the genomes were deleted. We concluded that deleted mtDNA molecules were primarily responsible for the phenotype in this patient.

publication date

  • August 1, 1997

Research

keywords

  • DNA, Mitochondrial
  • Electron Transport Complex IV
  • Mitochondrial Myopathies
  • Repetitive Sequences, Nucleic Acid
  • Sequence Deletion

Identity

Scopus Document Identifier

  • 0030854939

PubMed ID

  • 9266727

Additional Document Info

volume

  • 42

issue

  • 2