Important

It is possible that the main title of the report Kearns Sayre Syndrome (KSS) is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.

Synonyms

• Chronic Progressive External Ophthalmoplegia and Myopathy
• CPEO with Myopathy
• CPEO with Ragged-Red Fibers
• KSS
• Mitochondrial Cytopathy, Kearn-Sayre Type
• Oculocraniosomatic Syndrome (obsolete)
• Ophthalmoplegia, Pigmentary Degeneration of the Retina and Cadiomyopathy
• Kearns-Sayre Disease
• Chronic Progressive External Ophthalmoplegia with Ragged Red Fibers
  Ophthalmoplegia Plus Syndrome

Disorder Subdivisions

None

General Discussion

This disease entry was made possible due to the generosity of the Robert Lee and Clara Guthrie Patterson Trust, through grant funds provided for the National Organization for Rare Disorders' "Pediatric Rare Disease Database Project."

Kearns-Sayre Syndrome is a rare neuromuscular disorder characterized by three primary findings: progressive paralysis of certain eye muscles (chronic progressive external ophthalmoplegia [CPEO]); abnormal accumulation of colored (pigmented) material on the nerve-rich membrane lining the eyes (atypical retinitis pigmentosa), leading to chronic inflammation, progressive degeneration, and wearing away of certain eye structures (pigmentary degeneration of the retina); and heart disease (cardiomyopathy) such as heart block. Other findings may include muscle weakness, short stature, hearing loss, and/or the loss of ability to coordinate voluntary movements (ataxia) due to problems affecting part of the brain (cerebellum). In some cases, Kearns-Sayre Syndrome may be associated with other disorders and/or conditions.

Kearns-Sayre Syndrome belongs (in part) to a group of rare neuromuscular disorders known as mitochondrial encephalomyopathies. Mitochondrial encephalomyopathies are disorders in which a defect in genetic material arises from a part of the cell structure that releases energy (mitochondria), causing the brain and muscles to function improperly (encephalomyopathies). In these disorders, abnormally high numbers of defective mitochondria are present. In approximately 80 percent of cases of Kearns-Sayre Syndrome, tests will reveal missing genetic material (deletion) involving the unique DNA in mitochondria (mtDNA).