Lafora progressive myoclonus epilepsy is an autosomal recessive, fatal, generalized polyglucosan storage disorder that occurs
in childhood or adolescence with stimulus sensitive epilepsy (resting and action myoclonias, grand mal, and absence), dementia,
ataxia and rapid neurologic deterioration. Mutations in EPM2A/laforin cause 58% of cases and mutations in EPM2B/malin cause
35% of cases. Accumulating evidence points to Lafora disease as primarily a disorder of cell death with impaired clearance
of misfolded proteins, as shown by ubiquitin-positive aggresomes in HeLa cells transfected with mutated laforin, ubiquitin-positive
polyglucosan inclusion bodies, and malin/E3 ubiquitin ligase polyubiquitination of laforin. How polyglucosan inclusion bodies
accumulate is still a mystery. Polyglucosan accumulates hypothetically because of an overactive polyglucosan biosynthetic
pathway or a breakdown in polyglucosan degradation. Five separate laboratories are looking for the biochemical pathways that
connect laforin and malin to polyglucosan synthesis or degradation. A curative therapy for human Lafora disease with laforin
replacement therapy using neutral pegylated immunoliposomes is being investigated.