Rare Pulmonology News

Disease Profile

Kearns-Sayre syndrome

Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.
1-9 / 100 000

3,310 - 29,790

US Estimated

1-9 / 100 000

5,135 - 46,215

Europe Estimated

Age of onset

Infancy

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ICD-10

H49.8

Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease

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Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype

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X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.

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X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder

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Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

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Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.

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Not applicable

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Other names (AKA)

KSS; Ophthalmoplegia, pigmentary degeneration of retina, and cardiomyopathy; Oculocraniosomatic syndrome;

Categories

Congenital and Genetic Diseases; Ear, Nose, and Throat Diseases; Endocrine Diseases;

Summary

Kearns-Sayre syndrome (KSS) is a neuromuscular disorder defined by the triad of onset before age 20 years, pigmentary retinopathy (a "salt-and-pepper" pigmentation in the retina that can affect vision, but often leaves it intact), and progressive external ophthalmoplegia (PEO).[1][2][3] In addition, affected individuals have at least one of the following: cardiac conduction block, cerebrospinal fluid protein concentration greater than 100 mg/dL, or cerebellar ataxia. Kearns-Sayre syndrome is a mitochondrial DNA (mtDNA) deletion syndrome.[1] It results from abnormalities in the DNA of mitochondria small rod-like structures found in every cell of the body that produce the energy that drives cellular functions. This and other mitochondrial diseases correlate with specific DNA mutations that cause problems with many of the organs and tissues in the body, resulting in multisystem effects. Treatment for this slowly progressive disorder is generally symptomatic and supportive.[2]

Symptoms

Kearns-Sayre syndrome is characterized by progressive external ophthalmoplegia (PEO) and pigmentary retinopathy (a “salt-and-pepper” pigmentation in the retina that can affect vision, but often leaves it intact). These symptoms typically develop before 20 years of age.[1][3] At least one of the following must also be present: cardiac conduction block, cerebrospinal fluid protein concentration greater than 100 mg/dL, or cerebellar ataxia.[1]

Additional symptoms may include mild skeletal muscle weakness, short stature, hearing loss, impaired cognitive function, and diabetes mellitus. Seizures are infrequent. Several endocrine disorders can be associated with Kearns-Sayre syndrome, including delayed sexual maturation, hypothyroidism, and growth hormone deficiency.[1][2][3] 

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Abnormality of retinal pigmentation
0007703
Progressive external ophthalmoplegia
0000590
Third degree atrioventricular block
Complete heart block
0001709
30%-79% of people have these symptoms
Anterior hypopituitarism
0000830
Ataxia
0001251
EMG abnormality
0003457
Hearing impairment
Deafness
Hearing defect

[ more ]

0000365
Muscular hypotonia
Low or weak muscle tone
0001252
Progressive intervertebral space narrowing
0004622
Ragged-red muscle fibers
0003200
Reduced tendon reflexes
0001315
Skeletal muscle atrophy
Muscle degeneration
Muscle wasting

[ more ]

0003202
5%-29% of people have these symptoms
Delayed skeletal maturation
Delayed bone maturation
Delayed skeletal development

[ more ]

0002750
Hemiplegia/hemiparesis
Paralysis or weakness of one side of body
0004374
Percent of people who have these symptoms is not available through HPO
Arrhythmia
Abnormal heart rate
Heart rhythm disorders
Irregular heart beat
Irregular heartbeat

[ more ]

0011675
Basal ganglia calcification
0002135
Cardiomyopathy
Disease of the heart muscle
0001638
Dementia
Dementia, progressive
Progressive dementia

[ more ]

0000726
Diabetes mellitus
0000819
Hypoparathyroidism
Decreased parathyroid hormone secretion
0000829
Increased CSF protein
0002922
Lactic acidosis
Increased lactate in body
0003128
Microcephaly
Abnormally small skull
Decreased circumference of cranium
Decreased size of skull
Reduced head circumference
Small head circumference

[ more ]

0000252
Mitochondrial inheritance
0001427
Muscle weakness
Muscular weakness
0001324
Pigmentary retinopathy
0000580
Primary adrenal insufficiency
0008207
Ptosis
Drooping upper eyelid
0000508
Renal Fanconi syndrome
0001994
Renal tubular acidosis
Accumulation of acid in body due to kidney problem
0001947
Seizure
0001250
Sensorineural hearing impairment
0000407
Sensory neuropathy
Damage to nerves that sense feeling
0000763
Short stature
Decreased body height
Small stature

[ more ]

0004322
Sideroblastic anemia
0001924

Cause

Kearns-Sayre syndrome is caused by defects in mitochondria, which are structures within cells that us oxygen to convert the energy from food into a form that can be used by cells. This process is called oxidative phosphorylation. Although most DNA is packaged in chromosomes within the nucleus (nuclear DNA), mitochondria also have a small amount of their own DNA called mitochondrial DNA (mtDNA). This type of DNA contains many genes essential for normal mitochondrial function. People with Kearns-Sayre syndrome have a single, large deletion of mtDNA which results in the loss of genes important for mitochondrial formation and oxydative phosphorylation. While researchers have not determined how these deletions cause the features of Kearns-Sayre syndrome, they may be related to a lack of cellular energy The underlying cause of the deletion in affected individuals remains unknown.[4]

Treatment

Treatment for Kearns-Sayre syndrome is generally symptomatic and supportive.[2] Management options include placement of cardiac pacemakers in individuals with cardiac conduction blocks, eyelid slings for severe ptosis, cochlear implants and hearing aids for neurosensory hearing loss, hormone replacement for endocrinopathies, dilation of the upper esophageal sphincter to alleviate cricopharyngeal achalasia, folinic acid supplementation in individuals with Kearns-Sayre syndrome with low cerebral spinal fluid folic acid, administration of coenzyme Q10 and L-carnitine, physical and occupational therapy, and treatment of depression. Antioxidants may ameliorate damage from reactive oxygen species; percutaneous endoscopic gastrostomy may improve nutritional intake and prevent aspiration pneumonia in individuals with severe dysphagia. Surveillance includes EKG and echocardiogram every six to 12 months and yearly audiometry and endocrinologic evaluation.[1]

Organizations

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

    Organizations Providing General Support

      Learn more

      These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

      Where to Start

        In-Depth Information

        • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
        • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
        • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
        • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
        • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
        • PubMed is a searchable database of medical literature and lists journal articles that discuss Kearns-Sayre syndrome. Click on the link to view a sample search on this topic.

          References

          1. DiMauro S, Hirano M. Mitochondrial DNA Deletion Syndromes. GeneReviews. May 3, 2011; https://www.ncbi.nlm.nih.gov/books/NBK1203/.
          2. Kearns-Sayre Syndrome Information Page. National Institute of Neurological Disorders and Stroke (NINDS). June 4, 2012; https://www.ninds.nih.gov/Disorders/All-Disorders/Kearns-Sayre-Syndrome-Information-Page.
          3. Facts about Mitochondrial Myopathies. Muscular Dystrophy Association (MDA). 2011; https://static.mda.org/publications/PDFs/FA-MITO.pdf.
          4. Kearns-Sayre syndrome. Genetics Home Reference (GHR). December 2011; https://ghr.nlm.nih.gov/condition/kearns-sayre-syndrome.

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