The syndrome results from an abnormality in the DNA of mitochondria, which are small structures found in each cell of a person's body and produce energy that drives their cellular functions. Mutations in the person's mitochondria cause problems with a number of the tissues and organs in their body.
KSS appears to occur sporadically, affecting people from all ethnic backgrounds. In some cases, the syndrome may be associated with additional conditions or disorders. Kearns-Sayre syndrome belongs to a group of disorders referred to as, 'mitochondrial encephalomyopathies.'
Mitochondrial encephalomyopathies are disorders that cause a defect in a person's genetic material arising from a portion of their cell structure that releases energy, causing the person's brain and muscles to function improperly. Approximately eighty-percent of people with KSS present test results revealing missing genetic material involving the unique DNA in mitochondria. Kearns-Sayre syndrome is also known by the following names:
Symptoms of Kearns-Sayre Syndrome
KSS is characterized by a progressive limitation of the person's eye movements until they experience complete immobility of their eye, accompanied by eyelid droop. The syndrome is associated with an abnormal accumulation of pigmentation in the membrane of the lining of the person's eyes. Persons affected by the syndrome can experience paralysis of specific eye muscles that worsens over time, as well as degeneration of their retina, the portion of the eye that is responsible for sight.
Mitochondria are found in cells throughout a person's body. Due to this fact, Kearns-Sayre syndrome can affect a number of various organs and bodily systems. People with KSS might experience endocrine disorders, although seizure activity is infrequent. The potential symptoms involved with KSS are wide-ranging and may include:
There are two tests that may be performed should a diagnosis of Kearns-Sayre syndrome be suspected. The first involves checking the lactate and protein levels in the person's cerebrospinal fluid. If the person has KSS, levels of lactate and protein in their cerebrospinal fluid will be elevated. The other test involves examining a biopsy of the person's muscle in order to see if the DNA in their mitochondria is abnormal.
Medical science has not discovered either a form of treatment or a cure for Kearns-Sayre syndrome at this time. Unfortunately, the effects of the syndrome worsen over time. Many complications can develop in association with the syndrome such as heart failure, diabetes, and blindness. Complications of the syndrome are treated appropriately as they arise.
Exercise can assist in maintaining or increasing the person's muscle strength. Ubidecarenone, also known as, 'Coenzyme Q10,' might help to relieve the symptoms of KSS. People with Kearns-Sayre syndrome should also be regularly monitored by a cardiologist and an ophthalmologist. Future treatment of KSS may involve attempts to inhibit mutant mtDNA replication, or encourage replication of wild-type mtDNA.