Kearns-Sayre Syndrome

Kearns-Sayre syndrome (KSS) is a rare neuromuscular condition that impacts your eyes and other parts of your body, including your heart. It happens due to a defect in the DNA of mitochondria, which help produce most of your body’s energy. Most people with KSS develop symptoms before age 20. There isn’t a cure, but treatment options can help.


What is Kearns-Sayre syndrome?

Kearns-Sayre syndrome (KSS) is a rare neuromuscular condition. It impacts your eyes and other parts of your body, including your heart. Most people with KSS develop symptoms before age 20.


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Is Kearns-Sayre syndrome a mitochondrial disorder?

Kearns-Sayre Syndrome is a rare mitochondrial disease that doesn’t have a cure. It’s named for Thomas P. Kearns and George Pomeroy Sayre, who first described the disease in 1958. It worsens over time (progressive), leading to a range of health issues that often involve your eyes, heart, muscles and cognition (ability to think and reason). Early diagnosis and ongoing treatment can help you or your child manage symptoms for an improved quality of life.

What are mitochondrial disorders?

Mitochondria are tiny rod-like structures that exist in every cell of your body, except red blood cells. Mitochondria are the “energy factories” of your body. They produce 90% of the energy needed to support body function and growth. Mitochondria use oxygen to convert fuel from the food you eat into energy your cells can use.

When mitochondria are abnormal or damaged, they begin to fail. Your body doesn’t get enough energy to work properly.

Mitochondrial diseases are difficult to diagnose and treat because they affect multiple body systems (cells, tissues and organs). While symptoms of mitochondrial disease can vary in severity, they typically worsen over time. They often damage muscles and nerve cells, which depend on a lot of energy to work as they should.


Who gets Kearns-Sayre syndrome?

Kearns-Sayre syndrome can affect both men and women. Usually, the genetic changes that cause KSS happen as a baby develops during pregnancy. These genetic changes (mutations) occur in their mitochondria.

This genetic disorder can be passed down from mothers (maternal inheritance), but may also occur without a family history. Genetic testing may help to determine if the mutation was inherited (passed down) or not.

Are there other conditions like Kearns-Sayre syndrome?

Many conditions have symptoms that resemble Kearns-Sayre syndrome, affecting your eyes, muscles and other parts of your body. They include, but aren’t limited to:

  • Ataxia neuropathy spectrum, which causes coordination and balance problems (ataxia) and nerve issues (neuropathy).
  • Ophthalmoplegia-plus, which causes weakness or paralysis of your eye muscles.

Getting an accurate diagnosis is important, so you or your child can receive appropriate care for KSS.


Are there other names for Kearns-Sayre syndrome?

Other names for Kearns-Sayre syndrome are:

  • Kearns-Sayre mitochondrial cytopathy.
  • Oculocraniosomatic syndrome.

How common is Kearns-Sayre syndrome?

Kearns-Sayre syndrome is rare. An estimated 1 to 3 people out of every 100,000 have the disease.

Symptoms and Causes

What causes Kearns-Sayre syndrome?

KSS happens due to a genetic mutation in mitochondrial DNA (mtDNA). This type of DNA affects genes needed for healthy mitochondrial function. Researchers don’t know why the genetic change happens.

What are the symptoms of Kearns-Sayre syndrome?

Signs of Kearns-Sayre syndrome usually occur before age 20 and first affect your eyes. Over time, the disease may cause blindness. Early symptoms include:

  • Difficulty seeing, especially in dark environments, due to damage to your retina, the light-sensitive tissue of your eye (pigmentary retinopathy).
  • Drooping eyelids (ptosis).
  • Weak or paralyzed eye muscles (chronic progressive external ophthalmoplegia, or CPEO).

KSS also causes a range of other symptoms, including

Diagnosis and Tests

How is Kearns-Sayre syndrome diagnosed?

It can be challenging to diagnose Kearns-Sayre syndrome. It can involve many body systems. You may notice unusual symptoms in yourself or your child. Or a healthcare provider may notice symptoms during a checkup. If you observe any signs or symptoms, see your healthcare provider.

To diagnose KSS, healthcare providers:

  • Review your medical history and symptoms.
  • Perform a physical exam.
  • May other tests, including urine test, eye exam, hearing test, blood tests and spinal tap (lumbar puncture).
  • Might refer you for genetic counseling and testing (a blood test).

Your healthcare provider may also take a biopsy of your muscle tissue to look for ragged-red fibers. These indicate abnormal muscle cells due to mitochondrial disease. Imaging studies to rule out other conditions may include:

Early detection is essential for effective treatment. Getting the proper diagnosis ensures that you, or your child, receive appropriate care.

Management and Treatment

Is there a cure for Kearns-Sayre syndrome?

There isn’t a cure for Kearns-Sayre syndrome. Early detection and supportive care can help reduce the risk of complications. Your healthcare provider can recommend therapies to help you or your child manage symptoms so you can live a better quality of life.

Who might be on your child's treatment team for Kearns-Sayre syndrome?

Kearns-Sayre syndrome requires a range of expertise, as it can affect many parts of your body. Your care team may include:

  • Eye care specialist (ophthalmologist).
  • Hearing specialist (audiologist).
  • Heart specialist (cardiologist).
  • Hormone-related disease expert (endocrinologist).
  • Genetics specialist (geneticist).
  • Nervous system expert (neurologist).
  • Occupational or physical therapists.
  • Psychology specialist (neuropsychiatrist).

How is Kearns-Sayre syndrome treated?

Treatment focuses on managing symptoms and reducing complications as the condition progresses.

Physical and occupational therapy can help with coordination, strength and balance problems. Your healthcare provider may also prescribe medication to treat heart or hormone conditions or psychological symptoms such as depression.

Your healthcare provider may recommend:

Ongoing monitoring is necessary if you or your child has KSS. New symptoms often arise as organ systems fail over time. Talk to your healthcare provider about options to help you live longer and better.


How can I reduce my child’s risk of developing Kearns-Sayre syndrome?

There isn’t a way to prevent Kearns-Sayre syndrome, and nothing you do causes it. It happens due to genetic mutations as a baby develops in the womb.

Outlook / Prognosis

What’s the outlook for Kearns-Sayre syndrome?

The outlook for Kearns-Sayre syndrome depends on symptoms and their severity. Most people with the condition live for several decades. Supportive treatment options can provide you or your child a longer, healthier life.

Living With

When should I seek care for my child?

Early detection of Kearns-Sayre syndrome is important to manage symptoms and reduce the risk of complications. Genetic testing can confirm a diagnosis so you receive the appropriate care. Your healthcare provider works with you to customize a care plan that meets your needs and goals.

A note from Cleveland Clinic

Kearns-Sayre syndrome is a challenging disease to diagnose and treat, as it can affect so many parts of your body. Pay attention to how you feel as new symptoms arise. And check in with your healthcare provider regularly. Working together, you can find ways to address problems promptly so you stay as healthy as possible, for as long as possible.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 05/19/2022.

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