Kearns-Sayre syndrome

Kearns–Sayre syndrome (abbreviated KSS) also known as oculocraniosomatic disease or Oculocraniosomatic neuromuscular disease with ragged red fibers is a mitochondrial myopathy with a typical onset before 20 years of age. KSS is a more severe syndromic variant of chronic progressive external ophthalmoplegia (abbreviated CPEO), a syndrome that is characterized by isolated involvement of the muscles controlling eyelid movement (levator palpebrae, orbicularis oculi), and those controlling eye movement (extra-ocular muscles). This results in ptosis and ophthalmoplegia respectively. KSS involves a triad of the already described CPEO, as well as bilateral pigmentary retinopathy, and cardiac conduction abnormalities. Other areas of involvement...