Kearns-Sayre Syndrome Clinical Presentation

Updated: Aug 21, 2017
  • Author: Anna Purna Basu, BMBCh, PhD, MA, NIHR; Chief Editor: Luis O Rohena, MD, FAAP, FACMG  more...
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The following are noted in patients with Kearns-Sayre syndrome (KSS):

  • Muscle weakness
    • Chronic and progressive decreased eye movements and ptosis
    • Dysphagia
    • Skeletal muscle weakness (proximal more than distal) and exercise intolerance
  • CNS dysfunction
    • Ataxia
    • Dementia, encephalopathy, or specific focal neuropsychological deficits
    • Deafness
    • Night blindness
  • Cardiac disease
    • Syncope
    • Palpitations
  • Symptoms of endocrine dysfunction
    • Diabetes mellitus
    • Menstrual irregularities, delayed puberty
    • Poor growth, failure to thrive
    • Seizures due to hypocalcemia (hypoparathyroidism)


In patients with Kearns-Sayre syndrome, signs are as follows:

  • Muscle weakness
    • Proximal myopathy (difficulty rising from a squat)
    • Ptosis (usually bilateral but may be symmetrical initially)
    • External ophthalmoplegia (as is seen in the image below)
      Bilateral ptosis and external ophthalmoplegia. Top Bilateral ptosis and external ophthalmoplegia. Top: patient looking straight ahead. Below: patient is being asked to look in the direction of the arrow in each case. Restriction of eye movements in each direction is demonstrated.
  • CNS dysfunction
    • Retinitis pigmentosa
    • Cerebellar ataxia
    • Cognitive deficits [13]
    • Cataracts
    • Encephalopathy (in acute presentation with lactic acidosis)
  • Cardiac
    • Bradycardia
    • Congestive cardiac failure
  • Endocrine
    • Short stature (38% of affected individuals)
    • Hypogonadism (20% of affected individuals)
    • Other (eg, signs of hypothyroidism)


See the list below:

  • Kearns-Sayre syndrome occurs secondary to deletions in mtDNA (see Pathophysiology).