Kearns-Sayre Syndrome Clinical Presentation

Updated: Mar 24, 2021
  • Author: Anna Purna Basu, BMBCh, PhD, MA, NIHR; Chief Editor: Luis O Rohena, MD, PhD, 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 [6]

    • 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).