Kearns-Sayre Syndrome is usually diagnosed in childhood, and is caused by a large mutation or deletion of genetic material within the mitochondrial DNA.
It manifests in the form of a progressive degeneration of the eye muscles leading to blindness, and a disorder of the heart muscle leading to heart block. Other symptoms can include seizures and dementia.
Kearns-Sayre Syndrome is a qualifying condition for medical marijuana and individuals can benefit from the therapeutic effects.