Unverricht disease

Unverricht-Lundborg disease a slowly progressive autosomal recessive disorder, a form of progressive myoclonic epilepsy first seen in Finland. Onset is usually around the age of 10 and there are degenerative changes in the brain without presence of Lafora bodies. Myoclonic seizures are severe and continuous and tend to be triggered by movement, stress, and sensory stimuli, but mental deterioration is milder and survival is usually longer than in Lafora disease. It is associated with mutation in the gene encoding cystatin B, a cysteine protease inhibitor that blocks the actions of cathepsins; the mutation causes expansion of a minisatellite repeat sequence in the putative promoter region of the gene. Called also Baltic myoclonic epilepsy and progressive myoclonic epilepsy type 1 (EPM1).