| A mitochondrial encephalomyopathy with characteristics of myoclonic seizures. Patients usually present during adolescence or early adulthood with myoclonic epilepsy, sometimes with neurosensory deafness, optic atrophy, short stature or peripheral neuropathy. The disease is progressive with worsening of the epilepsy and onset of additional symptoms including ataxia, deafness, muscle weakness, and dementia. Caused by mutations in the mitochondrial DNA. |
