A rare genetic neuro-ophthalmological disease with characteristics of progressive weakness of the external eye muscles, resulting in bilateral ptosis and diffuse symmetric ophthalmoparesis. Additional signs may include skeletal muscle weakness, cataracts, hearing loss, sensory axonal neuropathy, ataxia, parkinsonism, cardiomyopathy, hypogonadism and depression. It is usually less severe than autosomal recessive form. [from
SNOMEDCT_US]