This is a recently described form of muscular dystrophy, one of many that are inherited.
The earliest sign consists of droopy eyelids, usually by the age of 22 years. Difficulty in moving the eyes in all directions is also common early. After a period of about 5 years, weakness in the facial muscles and in the limbs becomes noticeable. Swallowing and breathing become increasingly difficult. Weakness in the arms and legs eventually result in loss of mobility 20-40 years after the onset of symptoms. Atrophy (loss of muscle mass) is common and can be marked.
This is a rare form of muscular dystrophy and the causative mutation has not been identified. Most family patterns are consistent with autosomal dominant inheritance in which the disease appears in a vertical pattern as affected parents pass the disease directly to about 50% of their offspring.
Insufficient numbers of individuals have been reported to describe an accurate prognosis. Ophthalmologists and neurologists may collaborate on the diagnosis but clearly the major handicaps arise from muscle weakness. No effective treatment has been reported but physical therapy should be considered to preserve muscle function and mobility as long as possible. Respiratory therapy can be beneficial in selected cases.