Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004134 (ataxia)
 15,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The authors describe three siblings born to consanguineous parents with early onset ataxia, dysarthria, myoclonic, generalized tonic clonic seizures, upward gaze palsy, extensor plantar reflexes, sensory neuropathy, and normal cognition. Direct screening excluded mutations in FRDA, TDP1,and SACS genes and at 8344, 3243, and 8993 positions of mitochondrial DNA. Linkage analysis excluded AOA-1, EPM1, EPM2A, EPM2B, CAMOS, and recessive ataxias linked to chromosome 9q34-9qter. This clinical constellation may represent a distinct form of early onset cerebellar ataxia.
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PMID:An autosomal recessive cerebellar ataxia syndrome with upward gaze palsy, neuropathy, and seizures. 1564 21

Abstract 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.
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PMID:Advances in lafora progressive myoclonus epilepsy. 1776 34

A 22-year-old girl presented with convulsive status epilepticus and a previous history of recurrent seizures, myoclonus, ataxia and impaired cognitive functions. Neurological examination revealed rest and action-induced myoclonus, pyramidal signs and opposition hypertonia. Testing revealed severe metabolic acidosis, elevated transaminases and creatine kinase, and respiratory insufficiency. After intubation and ventilation, thiopental was introduced but the patient's condition worsened dramatically with death in a few hours. Autopsy showed profuse periodic acid-Schiff (PAS) positive intracellular inclusions in the CNS (Lafora bodies), most abundant in thalamus, cerebellum, and brainstem, as well as in other organs. Genetic testing revealed a homozygous missense mutation (c.205C > G, P69A) in the EPM2B (NHLRC1) gene, confirming the diagnosis of progressive myoclonic epilepsy Lafora-type.
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PMID:22-year-old girl with status epilepticus and progressive neurological symptoms. 1974 44

We report a patient with congenital generalized lipodystrophy who had suffered from seizures, myoclonus, ataxia and cognitive decline since late childhood. Lafora disease was diagnosed based on skin biopsy results, which revealed pathognomonic Lafora bodies. The results of genetic analysis for mutations in EPM2A and EPM2B genes were negative. This is the first case report describing an association between congenital generalized lipodystrophy and Lafora disease. Further studies focusing on the relationship between these two diseases and the identification of a third locus for Lafora disease are needed.
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PMID:Lafora disease and congenital generalized lipodystrophy: a case report. 1995 52

The most common progressive myoclonus epilepsies are the late infantile and late infantile-variant neuronal ceroid lipofuscinoses (onset before the age of 6 years), Unverricht-Lundborg disease (onset after the age of 6 years) and Lafora disease. Lafora disease is a distinct disorder with uniform course: onset in teenage years, followed by progressively worsening myoclonus, seizures, visual hallucinations and cognitive decline, leading to a vegetative state in status myoclonicus and death within 10 years. Biopsy reveals Lafora bodies, which are pathognomonic and not seen with any other progressive myoclonus epilepsies. Lafora bodies are aggregates of polyglucosans, poorly constructed glycogen molecules with inordinately long strands that render them insoluble. Lafora disease is caused by mutations in the EPM2A or EPM2B genes, encoding the laforin phosphatase and the malin ubiquitin ligase, respectively, two cytoplasmically active enzymes that regulate glycogen construction, ensuring symmetric expansion into a spherical shape, essential to its solubility. In this work, we report a new progressive myoclonus epilepsy associated with Lafora bodies, early-onset Lafora body disease, map its locus to chromosome 4q21.21, identify its gene and mutation and characterize the relationship of its gene product with laforin and malin. Early-onset Lafora body disease presents early, at 5 years, with dysarthria, myoclonus and ataxia. The combination of early-onset and early dysarthria strongly suggests late infantile-variant neuronal ceroid lipofuscinosis, not Lafora disease. Pathology reveals no ceroid lipofuscinosis, but Lafora bodies. The subsequent course is a typical progressive myoclonus epilepsy, though much more protracted than any infantile neuronal ceroid lipofuscinosis, or Lafora disease, patients living into the fourth decade. The mutation, c.781T>C (Phe261Leu), is in a gene of unknown function, PRDM8. We show that the PRDM8 protein interacts with laforin and malin and causes translocation of the two proteins to the nucleus. We find that Phe261Leu-PRDM8 results in excessive sequestration of laforin and malin in the nucleus and that it therefore likely represents a gain-of-function mutation that leads to an effective deficiency of cytoplasmic laforin and malin. We have identified a new progressive myoclonus epilepsy with Lafora bodies, early-onset Lafora body disease, 101 years after Lafora disease was first described. The results to date suggest that PRDM8, the early-onset Lafora body disease protein, regulates the cytoplasmic quantities of the Lafora disease enzymes.
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PMID:Early-onset Lafora body disease. 2296 47

Lafora disease (LD) is an autosomal recessive progressive myoclonus epilepsy with classic adolescent onset of stimuli sensitive seizures. Patients typically deteriorate rapidly with dementia, ataxia, vegetative failure and death by 25 years of age. LD is caused by homozygous mutations in EPM2A or EPM2B genes. We found four novel mutations in EPM2A - three in exon 4 (Q247X, H265R G279C) and one in exon 1 (Y86D) - and a previously described mutation in exon 4 (R241X). These five EPM2A mutations were found in four index cases and affected relatives. Patient 1 with classic LD was doubly heterozygous for H265R and R241X in exon 4; while Patient 2, who also had classic LD, was homozygous for Q247X in exon 4. Patient 3 with classic LD was homozygous for Y86D in exon 1, but the same mutation in his affected brother manifested an atypical earlier childhood onset. For the first time, we describe a later onset and slower progression of EPM2A-deficient LD seen in Patient 4 and her three sisters who were doubly heterozygous for R241X and G279C in exon 4. In these sisters, seizures started later at 21 to 28 years of age and progressed slowly with patients living beyond 30 years of age. Our observations suggest that variations in phenotypes of EPM2A-deficient LD, like an earlier childhood or adolescent or later adult onset with a rapid or slower course, depend on a second modifying factor separate from pathogenicity or exon location of EPM2A mutations. A modifying gene amongst the patient's genetic background or environmental factors may condition age of onset and rapid or slow progression of LD.
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PMID:Late onset Lafora disease and novel EPM2A mutations: breaking paradigms. 2524 53

Introduccion. La enfermedad de Lafora es una forma de epilepsia mioclonica progresiva de herencia autosomica recesiva, de inicio en la infancia tardia o en la adolescencia, y producida por mutaciones de perdida de funcion en los genes EPM2A o EPM2B, los cuales codifican para las proteinas laforina y malina, respectivamente. Desarrollo. Los principales sintomas de la enfermedad, que empeoran progresivamente, son mioclonias, crisis occipitales, crisis tonicoclonicas generalizadas, deterioro cognitivo, sintomas neuropsiquiatricos y ataxia. El curso es progresivo y fatal. Patologicamente, se caracteriza por la presencia de depositos de poliglucosanos (denominados cuerpos de Lafora) en el cerebro, el higado, el musculo y las glandulas sudoriparas. El diagnostico de enfermedad de Lafora se realiza mediante hallazgos clinicos, electrofisiologicos, histologicos y geneticos. En la actualidad no existe un tratamiento que erradique o prevenga su desarrollo. Tradicionalmente, se utilizan farmacos antiepilepticos para el tratamiento de las mioclonias y las convulsiones, aunque aparecen resistencias a estas. Conclusiones. La enfermedad de Lafora es una patologia rara que, pese a su baja prevalencia, supone graves consecuencias para los pacientes y sus cuidadores. Asi pues, resulta necesario continuar la investigacion para clarificar los mecanismos subyacentes y desarrollar nuevos tratamientos paliativos y curativos de la enfermedad.
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PMID:[Lafora disease: a review of the literature]. 3063 56