title: Kearns-Sayre syndrome: a case series of 35 adults and children.
abstract: BACKGROUND
  Kearns-Sayre syndrome (KSS) is a rare mitochondrial cytopathy, first described at Mayo Clinic in 1958.
  
  
  OBJECTIVE
  We aimed to define patient and disease characteristics in a large group of adult and pediatric patients with KSS.
  
  
  METHODS
  We retrospectively searched the Mayo Clinic medical index patient database for the records of patients with KSS between 1976 and 2009. The 35 patients identified with KSS were analyzed in terms of demographic characteristics, presenting signs and symptoms, diagnostic features, clinical evolution, and associations between disease features and the development of disability.
  
  
  RESULTS
  The mean (standard [SD]) age at KSS presentation was 17 (10) years, but the mean age at diagnosis was 26 (15) years. Ophthalmologic symptoms developed in all patients, and neurologic and cardiac involvement was common. Only four patients (11%) in the series died, but all deaths were from sudden cardiac events. The development of physical disability was significantly associated with cognitive decline (P=0.004) but not with other clinical features, such as sex or sudden cardiac death.
  
  
  CONCLUSIONS
  We report the largest case series to date of patients with KSS from a single institution. In addition to the conduction system abnormalities identified in previous series, our cohort included patients with syncope and sudden cardiac death. This underscores the need to consider formal electrophysiologic studies and prophylactic defibrillators in patients with KSS.
authors: Division of General Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors: Sherezade
authors: S
authors: Khambatta
authors: Division of General Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors: Douglas L
authors: DL
authors: Nguyen
authors: Division of General Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors: Thomas J
authors: TJ
authors: Beckman
authors: Division of General Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors: Christopher M
authors: CM
authors: Wittich
keywords: heart block; mitochondrial diseases; ophthalmoplegia; retinitis pigmentosa