Kearns-Sayre syndrome (KSS) is a rare neuromuscular disorder with onset usually before the age of 20. It is characterized by progressive external ophthalmoplegia (paralysis of the eye muscles) and mild skeletal muscle weakness. It may also be associated with other problems such as retinal pigmentation (abnormal accumulation of pigmented material on the membrane lining the eyes), cardiac conduction defects, short stature, hearing loss, increased cerebrospinal fluid protein, inability to coordinate voluntary movements (ataxia), impaired cognitive dysfunction, diabetes, and other endocrine disorders.
Treatment for KSS is generally symptomatic and supportive. Cardiac abnormalities may be treated with various cardiac drugs or a pacemaker.
The prognosis (likely outcome) for individuals with KSS varies depending on the severity of symptoms (problems).