Progressive myoclonus epilepsy of Unverricht-Lundborg type (EPM1; MIM 254800) is an autosomal recessive disorder that occurs with a low frequency in many populations but is more common in Finland and the Mediterranean region.
The new mutation further supports the argument that defects in the cystatin B gene cause the Unverricht-Lundborg form of progressive myoclonus epilepsy.
Several mutations have been described in the proteinase inhibitor cystatin B gene from individuals affected with progressive myoclonus epilepsy of the Unverricht-Lundborg type (EPM1).
Progressive myoclonus epilepsy of the Unverricht-Lundborg type (EPM1; MIM 254800) is an autosomal recessive disorder characterized by seizures, myoclonus and progression to cerebellar ataxia.
Progressive myoclonus epilepsy of Unverricht-Lundborg type (EPM1) is characterized by onset at age 6-15 years, stimulus-sensitive myoclonus, tonic-clonic seizures, and typical EEG findings, with marked sensitivity to photic stimulation.
To describe a patient who has 2 distinct, rare genetic disorders: myotonic dystrophy (DM, OMIM 160900) and progressive myoclonus epilepsy of the Unverricht-Lundborg type (EPM1, OMIM 254800).
EPM1 dodecamer repeat associated with the pathogenesis of progressive myoclonus epilepsy was also simulated and showed flexible nature suggesting a similar expansion mechanism.
Recently, expansion of a dodecamer repeat, (CCCCGCCCCGCG)n upstream of cystatin B gene has been shown to be the most common mutation associated with Progressive Myoclonus Epilepsy (EPM1) of Unverricht-Lundborg type.