Early-onset progressive myoclonic epilepsy with dystonia mapping to 16pter-p13.3.

The authors present three patients from a consanguineous family afflicted with novel recessive myoclonic epilepsy characterized by very early onset and a steadily progressive course. The onset is in early infancy, and death occurs in the first decade. In addition to various types of myoclonic seizures, episodic phenomena such as dystonias, postictal enduring hemipareses, autonomic involvements, and periods of obtundation and lethargy were also observed. Developmental and neurological retardation, coupled with systemic infections, leads to a full deterioration. The authors designated the disease progressive myoclonic epilepsy with dystonia (PMED). A genome scan for the family and subsequent fine mapping localized the gene responsible for the disease to the most telomeric 6.73 mega base pairs at the p-terminus of chromosome 16, with a maximum multipoint logarithm-of-odds score of 7.83 and a maximum two-point score of 4.25. A candidate gene was analyzed for mutations in patients, but no mutation was found.