Kearns-Sayre Syndrome is form of rare
mitochondrial cytopathy, first described by Thomas P. Kearns and George Pomeroy Sayre in 1958 and is characterized by progressive external opthalmoplegia, cardiac conduction block, pigmentary
retinal degeneration, variable number of red ragged fibers on muscle biopsy. It presents before the child reaches the age of twenty.
Kearns-Sayre syndrome may affect many organ systems and additional features may include
myopathy,
dystonia, bulbar symptoms in the form of
dysarthria and nasal regurgitation and bilateral facial weakness. Endocrine abnormalities (e.g., diabetes, growth retardation/short stature, and
hypoparathyroidism), bilateral sensorineural
deafness,
dementia,
cataracts, and
proximal renal tubular acidosis, skeletal muscle weakness (proximal more than distal) and exercise intolerance are additional features.
Kearns Sayre Syndrome occurs as a result of large-scale single deletions (or rearrangements) of
mitochondrial DNA (
mtDNA), which is usually not inherited but occurs spontaneously, probably at the germ-cell level or very early in embryonic development. No disease-modifying
therapy is available for
Kearns-Sayre syndrome (KSS). Management is supportive vigilance for detection of associated problems. In the future, potential treatment in patients with
Kearns-Sayre syndrome may attempt to inhibit mutant
mtDNA replication or encourage replication of wild-type
mtDNA.