Different copy numbers of apparently identically deleted mitochondrial DNA in tissues from a patient with Kearns-Sayre syndrome detected by PCR.

An apparently identical deletion of 4.977 bp in length (position 8,483-13,459) was detectable in the mitochondrial DNA from skeletal muscle, heart muscle, kidney, and liver of a patient with Kearns-Sayre syndrome. The proportion of deleted genome varied from 60% for the skeletal muscle to 15% for heart muscle and kidney, and was below 5% in the liver. The mtDNA heteroplasmy of the liver was only detectable after amplification by PCR. In skeletal and heart muscle histochemical and immunocytochemical findings concerning cytochrome c oxidase were in good correlation with the proportion of deleted mitochondrial DNA.