| Disease ID | Source | Name | Description |
| 254800 | OMIM | Epilepsy, progressive myoclonic 1 (EPM1) | A form of progressive myoclonic epilepsy, a clinically and genetically heterogeneous group of disorders defined by the combination of action and reflex myoclonus, other types of epileptic seizures, and progressive neurodegeneration and neurocognitive impairment. EPM1 is an autosomal recessive form characterized by severe, stimulus-sensitive myoclonus and tonic-clonic seizures. The onset, occurring between 6 and 13 years of age, is characterized by convulsions. Myoclonus begins 1 to 5 years later. The twitchings occur predominantly in the proximal muscles of the extremities and are bilaterally symmetrical, although asynchronous. At first small, they become late in the clinical course so violent that the victim is thrown to the floor. Mental deterioration and eventually dementia develop. The disease is caused by variants affecting the gene represented in this entry. |