What is KSS disease?

Kearns-Sayre syndrome (KSS) is a rare neuromuscular disorder with onset usually before the age of 20 years. It is the result of 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.

What causes KSS?

KSS is caused by deletions of large portions of mitochondrial DNA (mtDNA), resulting in the loss of genes involved in the oxidative phosphorylation pathway. Deletions are heteroplasmic (i.e. a single cell can harbor both deleted and normal DNA molecules). Symptoms only appear if the proportion of abnormal DNA is high.

Is KSS a mitochondrial disease?

KSS is a mitochondrial disorder that affects males and females in equal numbers. Onset is typically before the age of 20; however, symptoms may appear during infancy or adulthood. Eye abnormalities and developmental delays are often observed before the age of five.

Is Kearns-Sayre syndrome life expectancy?

What are the mortality and morbidity figures? Kearns-Sayre syndrome is a slowly progressive disorder that reduces life expectancy, but specific figures are not available. Prognosis depends on the severity and number of organs involved.

Is KSS inherited?

Inheritance. KSS is a genetic disease, which means it is caused by a genetic mutation present from birth.

What are the symptoms of Kearns Sayre syndrome?

In addition, people with Kearns-Sayre syndrome have at least one of the following signs or symptoms: abnormalities of the electrical signals that control the heartbeat (cardiac conduction defects), problems with coordination and balance that cause unsteadiness while walking (ataxia), or abnormally high levels of …

How common is Kearns-Sayre syndrome?

The prevalence of Kearns-Sayre syndrome is approximately 1 to 3 per 100,000 individuals.

How is Kearns Sayre syndrome inherited?

How is Kearns-Sayre syndrome inherited? Most cases of Kearns-Sayre syndrome are not inherited ; they arise from mutations in the body’s cells that occur after conception. This alteration, called a somatic mutation , is present only in certain cells. Rarely, this condition is inherited in a mitochondrial pattern.

How is the mitochondria implicated in Leigh syndrome?

In Leigh’s disease, genetic mutations in mitochondrial DNA interfere with the energy sources that run cells in an area of the brain that plays a role in motor movements. The primary function of mitochondria is to convert the energy in glucose and fatty acids into a substance called adenosine triphosphate ( ATP).

Why do children never inherit Kearns-Sayre syndrome from their fathers?

What are the symptoms of Kearns-Sayre syndrome?

How is a person’s life is affected by mitochondrial disease?

The parts of the body that tend to be most affected are those that need the most energy, such as the heart, brain, muscles and gastrointestinal tract. Symptoms can range from fatigue and exercise intolerance to hearing loss, seizures, strokes, heart failure, diabetes and kidney failure.