Lafora disease, also called Lafora progressive myoclonic epilepsy, is a fatal autosomal recessive genetic disorder characterized by the presence of inclusion bodies, known as Lafora bodies, within neurons and the cells of the heart, liver, muscle, and skin.:545
Most patients with this disease do not live past the age of twenty-five, and death within ten years of symptoms is usually inevitable  At this time there is no cure or treatment for this disease.
Epilepsy occurs in one percent of all humans. Progressive Myoclonic Epilepsies (PME) account for about one percent of all epilepsies. Lafora disease is one of the common PMEs. Symptoms of Lafora disease begin to manifest themselves in children from 10 to 17 years old. Males and females are equally affected.
Lafora disease is an autosomal recessive disorder, caused by mutations in one of two known genes, EPM2A and EPM2B. EPM2A codes for the protein laforin, a dual specificity phosphatase (DSP) with a carbohydrate binding domain (CBM-20). Surprisingly, vertebrates have only one such protein with DSP domain as well as CBM-20 domain. EPM2B encodes the protein malin, an E3 ubiquitin ligase. At least one other gene is thought to contribute to the disease. Both discovered genes are present on chromosome 6 in humans.
Lafora disease is distinguished by the presence of inclusions called "Lafora bodies" within the cytoplasm, the viscous fluidic matrix inside of cells. Lafora bodies are composed of abnormal glycogen called polyglucosans. These starch-like polyglucosans are insoluble and hence precipitate inside cells.
Polyglucosan bodies appear with age; in Lafora disease, their numbers have increased enormously. Lafora bodies have been observed in virtually all organs of patients with the disease. In the brain, their presence appears to be restricted to neurons; they do not seem to present in astrocytes. Their morphology varies from tissue to tissue, but they generally contain a central core and have a peripheral fluffy appearance.
Patients develop the first symptoms mainly during adolescence. Major problems include seizures, drop attacks, myoclonus, ataxia, and, most significantly, a quickly developing, progressive and severe dementia.
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