Mitochondrial DNA deletions in progressive external ophthalmoplegia and Kearns-Sayre syndrome.

TitleMitochondrial DNA deletions in progressive external ophthalmoplegia and Kearns-Sayre syndrome.
Publication TypeJournal Article
Year of Publication1989
AuthorsMoraes, CT, DiMauro, S, Zeviani, M, Lombès, A, Shanske, S, Miranda, AF, Nakase, H, Bonilla, E, Werneck, LC, Servidei, S
JournalN Engl J Med
Date Published1989 May 18
KeywordsBlotting, Southern, Chromosome Deletion, DNA, Mitochondrial, Humans, Kearns-Sayre Syndrome, Mitochondria, Muscle, NADH Dehydrogenase, NADPH-Ferrihemoprotein Reductase, Ophthalmoplegia, Phenotype, Succinate Cytochrome c Oxidoreductase

We investigated the correlations of deletions of mitochondrial DNA in skeletal muscle with clinical manifestations of mitochondrial myopathies, a group of disorders defined either by biochemical abnormalities of mitochondria or by morphologic changes causing a ragged red appearance of the muscle fibers histochemically. We performed genomic Southern blot analysis of muscle mitochondrial DNA from 123 patients with different mitochondrial myopathies or encephalomyopathies. Deletions were found in the mitochondrial DNA of 32 patients, all of whom had progressive external ophthalmoplegia. Some patients had only ocular myopathy, whereas others had Kearns-Sayre syndrome, a multisystem disorder characterized by ophthalmoplegia, pigmentary retinopathy, heart block, and cerebellar ataxia. The deletions ranged in size from 1.3 to 7.6 kilobases and were mapped to different sites in the mitochondrial DNA, but an identical 4.9-kilobase deletion was found in the same location in 11 patients. Biochemical analysis showed decreased activities of NADH dehydrogenase, rotenone-sensitive NADH-cytochrome c reductase, succinate-cytochrome c reductase, and cytochrome c oxidase, four enzymes of the mitochondrial respiratory chain containing subunits encoded by mitochondrial DNA. We conclude that deletions of muscle mitochondrial DNA are associated with ophthalmoplegia and may result in impaired mitochondrial function. However, the precise relation between clinical and biochemical phenotypes and deletions remains to be defined.

Alternate JournalN. Engl. J. Med.
Citation Key10.1056/NEJM198905183202001
PubMed ID2541333
Grant ListNS-11766 / NS / NINDS NIH HHS / United States