Definition A severe, autosomal recessive form (OMIM:254780) of adolescent-onset progressive epilepsy. Typically, as seizures increase in frequency, cognitive function declines towards dementia; affected individuals die within 10 years of onset. While Lafora disease occurs worldwide, it is more common in the Mediterranean rim (southern Europe, northern Africa, Middle East) and in southern India.
Micro Accumulation of starch-like polyglucosans (Lafora bodies) that are most abundant in organs with the highest glucose metabolism, located in neuronal dendrites but not axons; the polyglucosan fibrils are associated with endoplasmic reticulum.
Molecular pathology Defects of NHLRC1, which encodes an E3 ubiquitin ligase that, with EPM2A/laforin and HSP70, suppresses misfolded protein toxicity by driving misfolded protein degradation via the ubiquitin-proteasome system, cause Lafora disease/epilepsy—progressive myoclonic 2.
Synonyms Epilepsy—progressive myoclonic 2, epilepsy—progressive myoclonic 2A, EPM2, EPM2A, Lafora body disease, LBD, myoclonic epilepsy of Lafora, MELF