Kearns Sayre Syndrome (KSS) is a rare disorder classified as one of the mitochondrial DNA deletion syndromes.

Genetic testing: variable single mtDNA (mitochondrial DNA) deletions


Onset: before age 20


Clinical features:

(1) pigmentary retinopathy (retinitis pigmentosa)

(2) progressive external ophthalmoplegia (PEO)

(3) cerebellar ataxia

(4) leukoencephalopathy with intellectual disability and/or dementia

(5) sensorineural hearing loss

(6) ptosis

(7) oropharyngeal dysfunction

(8) esophageal dysfunction

(9) myopathy with muscle weakness and exercise intolerance

(10) cardiac conduction block

(11) cardiomyopathy

(12) endocrinopathy (diabetes mellitus, hypoparathyroidism, hypothyroidism, adrenal insufficiency)

(13) pancreatic exocrine failure

(14) short stature

(15) renal dysfunction


Laboratory findings:

(1) elevated serum lactate and pyruvate

(2) elevated CSF protein (> 1 g/L)

To read more or access our algorithms and calculators, please log in or register.