Kearns-Sayre syndrome
Findings
No curated finding names Kearns-Sayre syndrome yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Kearns-Sayre syndrome (KSS) is a mitochondrial disease characterized by progressive external ophthalmoplegia (PEO), pigmentary retinitis and an onset before the age of 20 years. Common additional features include deafness, cerebellar ataxia and heart block.
Definition from the Mondo Disease Ontology (MONDO:0010787), read 2026-09-29. CC BY 4.0.
Features
31 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- Pigmentary retinopathyHPOHP:0000580
- Very frequent (80% to 99% of cases)
- Progressive external ophthalmoplegiaHPOHP:0000590
- Very frequent (80% to 99% of cases)
- Third degree atrioventricular blockHPOHP:0001709
- Very frequent (80% to 99% of cases)
- Anterior hypopituitarismHPOHP:0000830
- Frequent (30% to 79% of cases)
- AtaxiaHPOHP:0001251
- Frequent (30% to 79% of cases)
- Diminished deep tendon reflexHPOHP:0001315
- Frequent (30% to 79% of cases)
- EMG abnormalityHPOHP:0003457
- Frequent (30% to 79% of cases)
- Hearing impairmentHPOHP:0000365
- Frequent (30% to 79% of cases)
- HypotoniaHPOHP:0001252
- Frequent (30% to 79% of cases)
- Increased CSF protein concentrationHPOHP:0002922
- Frequent (30% to 79% of cases)
- Progressive intervertebral space narrowingHPOHP:0004622
- Frequent (30% to 79% of cases)
- PtosisHPOHP:0000508
- Frequent (30% to 79% of cases)
Show the remaining 19
- Ragged-red muscle fibersHPOHP:0003200
- Frequent (30% to 79% of cases)
- Skeletal muscle atrophyHPOHP:0003202
- Frequent (30% to 79% of cases)
- CardiomyopathyHPOHP:0001638
- Occasional (5% to 29% of cases)
- Chronic kidney diseaseHPOHP:0012622
- Occasional (5% to 29% of cases)
- Cognitive impairmentHPOHP:0100543
- Occasional (5% to 29% of cases)
- Delayed pubertyHPOHP:0000823
- Occasional (5% to 29% of cases)
Genes
1 gene
Germline variants in the gene encoding each protein, as classified by GenCC submitters, each in their own words. Limited, disputed and refuted submissions are listed too.
- RRM2BHGNC:17296
- Supportive · Orphanet · Autosomal recessive · 2021