Most people with Kearns-Sayre syndrome have a single, large deletion of mitochondrial DNA.The deletions range from 1,000 to 10,000 nucleotides, and the most common deletion is 4,997 nucleotides.Oxidative phosphorylation is a process that uses oxygen and simple sugars to create adenosine triphosphate (ATP), the cell's main energy source.
This condition results from a combination of genetic, environmental, and lifestyle factors, many of which have not been identified.
As people age, mitochondrial DNA accumulates damaging mutations, including deletions and other changes.
oxidase deficiency (also known as complex IV deficiency), which is a condition that can affect several parts of the body, including the muscles used for movement (skeletal muscles), the heart, the brain, or the liver.
The mitochondrial genes associated with cytochrome oxidase is responsible for the last step in oxidative phosphorylation before the generation of ATP.
As a result, reactive oxygen species easily damage mitochondrial DNA, causing cells to malfunction and ultimately to die.
Cells that have high energy demands, such as those in the inner ear that are critical for hearing, are particularly sensitive to the effects of mitochondrial DNA damage.
Mitochondrial DNA contains 37 genes, all of which are essential for normal mitochondrial function.
Thirteen of these genes provide instructions for making enzymes involved in oxidative phosphorylation.
The mitochondrial DNA mutations that cause this condition alter the subunit proteins that make up cytochrome oxidase disrupts the last step of oxidative phosphorylation, causing a decrease in ATP production.
Researchers believe that impaired oxidative phosphorylation can lead to cell death in tissues that require large amounts of energy, such as the brain, muscles, and heart.
Mitochondria are structures within cells that convert the energy from food into a form that cells can use.