Walsh & Hoyt: Single Deletions of mtDNA in Sporadic Opthalmoplegia

Most cases of CPEO and KSS are sporadic and associated with single deletions of mtDNA. Deleted mtDNAs appear to be distributed to a wider variety of tissues in KSS than CPEO, and duplications of mtDNA appear to be present in all cases of KSS but are absent in CPEO. Duplications of mtDNA are also found in patients with either diabetes mellitus or Pearsons syndrome, a mitochondrial disease characterized by infantile sideroblastic pancytopenia, insufficiency of the pancreas, and hepatic dysfunction.