Kearns Sayre Syndrome

Contact our caring team on 0800 652 3181 for help and support. Our phone lines open 10am-4pm, Monday to Friday.

Calls are free from UK landlines and mobiles. Calls from business lines may be charged – please check with your provider.

Prefer to email? Our email address is contact@metabolicsupport.org.

This disorder affects your mitochondria, which release energy into your cells. Your body is made up of different cells that each have their own specific roles. These cells need energy so that they can carry out their functions in the body. 

With Kearns Sayre syndrome, a significant amount of the genetic material in the mitochondria DNA (mtDNA) has been deleted. Therefore, your cells cannot get the energy needed to function as normal. Affected muscles and organs cannot carry out their roles properly and you may develop complications that are likely to get progressively worse over time. 

KSS has been reported in anywhere between 1 and 9 in every 100,000 people, although the exact numbers are not known. Males and females are equally likely to be affected, and race and ethnicity do not seem to have any effect on the likelihood of being diagnosed with KSS. 

Symptoms usually appear before 20 years old. They are progressive, so they will become more prominent as time goes on. It is important to get any potential symptoms checked as soon as possible by your medical team. 

There are three main symptoms that are typical of KSS. These are: 

• Progressive paralysis of your eye muscles, which may look like drooping eyelids (ptosis) or inability to move your eyes. People with this symptom are more likely to move their head and neck to see, instead of their eyes. 
• An accumulation of pigment on your eyes, which normally looks like spots in your vision. 
• Heart disease, blockages, or abnormalities. 

You may also be affected by a number of other symptoms that are common in people with KSS: 

• Problems with coordination and balance (ataxia) 
• Developmental delays 
• Short in height (dwarfism) 
• Hearing loss or deafness 
• Loss of vision 
• Memory loss 

Life expectancy depends on the organs that are affected. However, with proper support and treatment, many people live a long life.

To diagnose KSS, medical professionals will look for the three main symptoms of the disorder and whether they have begun before you reach 20 years old. A molecular genetic test will confirm the diagnosis. 

Specialised tests such as an electrocardiogram (sensors attached to your skin to monitor your heart), muscle biopsy (a sample of tissue taken from your muscle), and a lumbar puncture (a needle in your back to take fluid from your spinal cord, also known as a spinal tap) are used to check the seriousness of the symptoms. 

KSS may be diagnosed as another disease that involves large mtDNA deletions. It may also be mistaken for Pearson syndrome, or maternally-inherited progressive external ophthalmoplegia. 

This disorder is not currently detected as part of the newborn screening process in the UK or in other countries. 

Treatment is available to help you to manage the syndrome, however there is no cure for KSS.  

Your medical team may recommend inserting things such as a pacemaker or other instrument to help with any heart issues. You may also need hearing aids or eye surgery. This will be dependent on how KSS affects you. For more information, speak to your medical team. 

Although KSS is not curable, it is manageable with guidance and medical intervention. Most people with the disorder can expect a typical life expectancy, but this is dependent on the severity of your symptoms and the organs that are affected. 

KSS is very rarely inherited from parents. There is only a 4% chance of a mother passing KSS to her child.   

The disorder is typically caused by a mutation of your mitochondrial DNA, which means it is sporadic (happens for no apparent reason). It is unlikely that anybody else in your family will also have KSS.

References are available on request. Please contact us on 0800 652 3181 or by emailing contact@metabolicsupport.org.

Please note calls to 0800 numbers are free from UK landlines and mobiles. Calls from business lines may be charged – please check with your provider.

This information about metabolic diseases is provided by Metabolic Support UK and is intended for educational purposes only. It should not be used for diagnostic or treatment purposes.

Should you require more detailed information please contact Metabolic Support UK by email (contact@metabolicsupport.org) or by telephone ( 0800 652 3181). For specific medical information regarding a disorder or individual please contact your GP or Paediatrician. Metabolic Support UK accepts no responsibility for any errors or omissions nor does Metabolic Support UK assume any liability of any kind for the content of any information contained within this summary or any use that you may make of it.