researchers reported a study with modest results in five patients affected by either Pearson syndrome or Kearns–Sayre syndrome. History The triad of CPEO, bilateral pigmentary retinopathy, and cardiac conduction abnormalities was first described in a case report of two patients in 1958 by Thomas P. Kearns (1922–2011), MD., and George Pomeroy Sayre (1911–1992), MD. A second case was published in 1960 by Jager and co-authors reporting these symptoms in a 13-year-old boy. Previous cases of patients with CPEO dying suddenly had been published, occasionally documented as from a cardiac dysrhythmia. Other cases had noted a peculiar pigmentation of the retina, but none of these publications had documented these three pathologies occurring together as a genetic syndrome. Kearns published a defining case in 1965 describing nine unrelated cases with this triad. In 1988, the first connection was made between KSS and large-scale deletions of muscle mitochondrial DNA (abbreviated mtDNA) Since this discovery, numerous deletions in mitochondrial DNA have been linked to the development of KSS. References External links Mitochondrial diseases Rare syndromes Syndromes affecting the endocrine system Disorders of ocular muscles, binocular movement, accommodation and refraction Syndromes affecting the heart Syndromes affecting the eye Syndromes affecting hearing Syndromes including diabetes mellitus