ABSTRACT
Kearns-Sayre syndrome (KSS) is a specific mitochondrial disorder first described by Kearns and Sayre in 1958. In the majority of the cases, KSS is due to heteroplasmic mtDNA deletions of 1000–10000 nucleotides in length. Clinically, the diagnosis is established if the triad PEO, pigmentary retinopathy, and onset <20y of age is present and if at least one of a secondary triad feature, such as cardiac conduction defect, CSF protein >100mg/dl, or cerebellar disturbance is present. The initial manifestation is usually ptosis, followed by PEO. Cardiac involvement occurs in about 50% of the cases and is associated with sudden cardiac death (SCD) in about 20% of the cases. Cardiac involvement most frequently manifests as conduction defects and supraventricular and ventricular arrhythmias. About 20% of the patients develop diabetes. Other frequent features are short stature, hypoacusis, respiratory insufficiency, pyramidal signs, seizures, and mental retardation. Treatment is restricted to symptomatic measures, including implantation of pacemakers or ICDs, growth hormone therapy, hearing devices, tube feeding, and application of coenzyme-Q, The most important prognostic factor for life expectancy in KSS is cardiac disease. Despite appropriate cardiac therapy, however, life expectancy of KSS patient is still reduced.
