Lafora disease

Last updated
Lafora disease
Other namesLafora progressive myoclonic epilepsy, or MELF [1]
Specialty Neurology   OOjs UI icon edit-ltr-progressive.svg
Usual onsetLate childhood and adolescence, usually ages 8–19 years [2]
CausesMutation in either the EPM2A or EPM2B [NHLRC1] genes [3]
Differential diagnosis Other progressive myoclonic epilepsies (sialidosis, myoclonic epilepsy with ragged red fibers, Unverricht-Lundborg disease), Juvenile Myoclonic Epilepsy, Subacute sclerosing panencephalitis, schizophrenia [2]
Prognosis Universally fatal; most of the time, death occurs within 10 years after onset of initial symptoms.

Lafora disease is a rare, adult-onset and autosomal recessive [4] genetic disorder which results in myoclonus epilepsy and usually results in death several years after the onset of symptoms. The disease is characterized by the accumulation of inclusion bodies, known as Lafora bodies, within the cytoplasm of the cells in the heart, liver, muscle, and skin. [5] :545 Lafora disease is also a neurodegenerative disease that causes impairment in the development of brain (cerebral) cortical neurons and is a glycogen metabolism disorder. [6]

Contents

Lafora disease (LD) was described by the Spanish neuropathologist Gonzalo Rodríguez Lafora (1886–1971) in 1911, while directing the Neuropathology Section at the Government Hospital for Mental Insane (current NIH, US). [7]

Lafora disease is rare, meaning it is very rare in children, adolescents and adults worldwide. However, it has a higher incidence among children and adolescents with ancestry from regions where consanguineous relationships are common, namely the Mediterranean (North Africa, Southern Europe), the Middle East, India, and Pakistan. [2] Dogs can also have the condition. In dogs, Lafora disease can spontaneously occur in any breed, but the miniature wire-haired dachshund, bassett hound, and beagle are predisposed. [8]

Most patients with this disease do not live past the age of twenty-five, and it often leads to death within ten years of symptoms appearing. Late onset symptoms of this disease can begin at any age depending on the genes affected. [9] At present, there is no cure for this disease, but there are ways to deal with symptoms through treatments and medications. There are five patient organizations worldwide that share resources and support the Lafora patient community. [10]

Signs and symptoms

Symptoms of Lafora disease begin to develop during the early adolescent years, and symptoms progress as time passes. Prior to this, there is generally no indication of the presence of the disease, though in a few cases, the disease presents as a learning disorder around five years of age. [11] In extremely rare cases, symptoms may not show at all until as late as the third decade of life, though these cases have slower progression than typical LD. [12] The most common feature of Lafora disease is seizures that have been reported mainly as occipital seizures and myoclonic seizures with some cases of generalized tonic-clonic seizures, atypical absence seizures, and atonic and complex partial seizures. [2] [13] Other symptoms common with the seizures are drop attacks, ataxia, temporary blindness, visual hallucinations, and a quickly-developing and dramatic dementia. [4] [13]

Other common signs and symptoms associated with Lafora disease are behavioral changes due to the frequency of seizures. [14] Over time those affected with Lafora disease have brain changes that cause confusion, speech difficulties, depression, decline in intellectual function, impaired judgement and impaired memory. [14] If areas of the cerebellum are affected by seizures, it is common to see problems with speech, coordination, and balance in Lafora patients. [14]

For dogs that are affected with Lafora disease, common symptoms are rapid shuddering, shaking, or jerking of the canine's head backwards, high pitched vocalizations that could indicate the dog is panicking, seizures, and – as the disease progresses – dementia, blindness, and loss of balance.[ citation needed ]

Within ten years of developing symptoms, life expectancy declines. People who advance to adulthood tend to lose their ability to do daily tasks by themselves, which can require comprehensive care. If their symptoms progress extremely quickly or at an early age, patients receive comprehensive care, which – besides medication – means support during daily activities both physically and mentally. [15] [16]

Genetics

Lafora disease is an autosomal recessive disorder, caused by loss of function mutations in either the laforin glycogen phosphatase gene ( EPM2A ) or malin E3 ubiquitin ligase gene ( NHLRC1 ). [17] [18] These mutations in either of these two genes lead to polyglucosan formation or lafora body formation in the cytoplasm of heart, liver, muscle, and skin. [17]

'Graph 1' shows the data for 250 families that have been affected by Lafora disease and the distribution of cases around the world. The graph shows that there is a very large number of cases in Italy because of a higher occurrence of EPM2A gene mutation compared to any other country in the world. [19]

'Graph 1' Represents data that shows how Lafora disease has been distributed throughout not just the United States but the world as a whole. This particular graph shows 250 families that have been affected by Lafora Disease. Number of Cases of Lafora Disease per country.jpg
'Graph 1' Represents data that shows how Lafora disease has been distributed throughout not just the United States but the world as a whole. This particular graph shows 250 families that have been affected by Lafora Disease.
'Graph 2' Represents data that shows how the gene mutation for both EPM2A and EPM2B has been distributed around the world. The data goes to show that there are more cases caused by EPM2B than there are for EPM2B (NHLRC1). Percentage of Lafora Disease in each country.jpg
'Graph 2' Represents data that shows how the gene mutation for both EPM2A and EPM2B has been distributed around the world. The data goes to show that there are more cases caused by EPM2B than there are for EPM2B (NHLRC1).

'Graph 2' shows the percentage distribution of the cases from either an EPM2A gene mutation or an EPM2B (NHLRC1) gene mutation. 42% of the cases are caused by EPM2A and 58% are caused by EPM2B (NHLRC1). The most common mutation on the EPM2A gene is the R241X mutation. This genetic mutation is the cause for 17% of the EPM2A-caused Lafora disease cases. [19]

EPM2A codes for the protein laforin, a dual-specificity phosphatase that acts on carbohydrates by taking phosphates off. [17]

NHLRC1 encodes the protein malin, an E3 ubiquitin ligase, that regulates the amount of laforin. [17]

Laforin is essential for making the normal structure of a glycogen molecule. When the mutation occurs on the EPM2A gene, laforin protein is down-regulated and less of this protein is present or none is made at all. If there is also a mutation in the NHLRC1 gene that makes the protein malin, then laforin cannot be regulated and thus less of it is made.

Less laforin means more phosphorylation of glycogen, causing conformational changes, rendering it insoluble, leading to an accumulation of misformed glycogen, which has neurotoxic effects.

Lafora disease has an autosomal recessive pattern of inheritance. EPM2A gene found on chromosome 6q24 and NHLRC1 gene found on chromosome 6p22.3. Autorecessive.svg
Lafora disease has an autosomal recessive pattern of inheritance. EPM2A gene found on chromosome 6q24 and NHLRC1 gene found on chromosome 6p22.3.

In a laforin mutation, glycogen would be hyperphosphorylated; this has been confirmed in laforin knock-out mice. [21]

Research literature also suggests that over-activity of glycogen synthase, the key enzyme in synthesizing glycogen, can lead to the formation of polyglucosans and it can be inactivated by phosphorylation at various amino acid residues by many molecules, including GSK-3beta, Protein phosphatase 1, and malin. [22] [23] [24]

As defective enzyme molecules participate in the production of these molecules (GSK-3beta, PP1, and malin), excessive glycogen synthase activity occurs in combination with mutations in laforin that phosphorylates the excess glycogen being made, rendering it insoluble. The key player missing is ubiquitin. It is not able to degrade the excess amount of the insoluble lafora bodies. Since mutations arise in malin, an e3 ubiquitin ligase, this directly interferes with the degradation of laforin, causing the laforin not to be degraded. In this case laforin is then hyperphosphorylated. [25]

Lafora bodies

Lafora disease is distinguished by the presence of inclusions called Lafora bodies within the cytoplasm of cells. Lafora bodies are aggregates of polyglucosans or abnormally shaped glycogen molecules. [26] Glycogen in Lafora disease patients has abnormal chain lengths, which causes them to be insoluble, accumulate, and have a neurotoxic effect. [27]

For glycogen to be soluble, there must be short chains and a high frequency of branching points, but this is not found in the glycogen in Lafora patients. LD patients have longer chains that have clustered arrangement of branch points that form crystalline areas of double helices making it harder for them to clear the blood-brain barrier. [27] The glycogen in LD patients also has higher phosphate levels and is present in greater quantities. [27]

Diagnosis

Lafora disease is diagnosed by conducting a series of tests by a neurologist, epileptologist (person who specializes in epilepsy), or geneticist. To confirm the diagnosis, an EEG, MRI, and genetic testing are needed. [14] A biopsy may be necessary as well to detect and confirm the presence of Lafora bodies in the skin. [14]

Epidemiology

All the reports that have been published on Lafora disease have shown that the overall prevalence of the disease is about 4 cases per million individuals around the world. Lafora disease is much more prevalent in countries that have higher cases of inbreeding. Usually, these locations are geographically or culturally more isolated from the world at large. [28]

Treatment

There is no cure for Lafora disease with treatment being limited to controlling seizures through anti-epileptic and anti-convulsant medications. [29] The treatment is usually based on the individual's specific symptoms and the severity of those symptoms. Some examples of medications include valproate, levetiracetam, topiramate, benzodiazepines, or perampanel. [30] Although the symptoms and seizures can be controlled for a long period by using anti-epileptic drugs, the symptoms will progress and patients lose their ability to perform daily activities leading to the survival rate of approximately 10 years after symptoms begin. [30] Quality of life worsens as the years go on, with some patients requiring a feeding tube so that they can get the nutrition and medication they need in order to keep living, but not necessarily functioning. [30] Recently Metformin is approved for the treatment.

Research

Gonzalo Rodriguez Lafora, discoverer of the disease Gonzalo Rodriguez Lafora (1910).jpg
Gonzalo Rodríguez Lafora, discoverer of the disease

The disease is named after Gonzalo Rodríguez Lafora (1886–1971), a Spanish neuropathologist who first recognized small inclusion bodies in Lafora patients in the early to mid 1900s. [31]

Recent research has investigated whether inhibition of glycogen synthesis through restriction of glucose intake could potentially stop the formation of the Lafora Bodies in neurons in laforin-deficient mice models while also reducing the chances of seizures. [32] [ non-primary source needed ]

Researchers in the U.S., Canada, and Europe formed the Lafora Epilepsy Cure Initiative with funding from the National Institutes of Health. The group aims to interrupt the process of how the mutations in laforin and malin interfere with normal carbohydrate metabolism in mice models. [33]

Patient organizations

There are patient organizations in the United States (Chelsea's Hope), Italy (Tempo Zero and A.I.L.A.), France (France Lafora), and Spain (AEVEL).

Chelsea’s Hope began as a website in the fall of 2007 as a means to share Chelsea Gerber’s story with her family and friends. As the Gerber family connected with others affected by Lafora, they formed a patient advocacy organization in September 2009. Chelsea’s Hope Lafora Children Research Fund is an IRS 501(c)3 non-profit organization, EIN: 27-1008382. The mission of Chelsea’s Hope is to improve the lives of those affected by Lafora Disease and help accelerate the development of treatments. [34]

In 2016, shortly before Chelsea's death, her mother Linda recorded a video sharing a day in their life. [35] From myoclonus to a feeding tube replacement, viewers can learn what it means to live with Lafora Disease.

Related Research Articles

<span class="mw-page-title-main">Tuberous sclerosis</span> Genetic condition causing non-cancerous tumours

Tuberous sclerosis complex (TSC) is a rare multisystem autosomal dominant genetic disease that causes non-cancerous tumours to grow in the brain and on other vital organs such as the kidneys, heart, liver, eyes, lungs and skin. A combination of symptoms may include seizures, intellectual disability, developmental delay, behavioral problems, skin abnormalities, lung disease, and kidney disease.

<span class="mw-page-title-main">Myoclonus</span> Involuntary, irregular muscle twitch

Myoclonus is a brief, involuntary, irregular twitching of a muscle, a joint, or a group of muscles, different from clonus, which is rhythmic or regular. Myoclonus describes a medical sign and, generally, is not a diagnosis of a disease. It belongs to the hyperkinetic movement disorders, among tremor and chorea for example. These myoclonic twitches, jerks, or seizures are usually caused by sudden muscle contractions or brief lapses of contraction. The most common circumstance under which they occur is while falling asleep. Myoclonic jerks occur in healthy people and are experienced occasionally by everyone. However, when they appear with more persistence and become more widespread they can be a sign of various neurological disorders. Hiccups are a kind of myoclonic jerk specifically affecting the diaphragm. When a spasm is caused by another person it is known as a provoked spasm. Shuddering attacks in babies fall in this category.

<span class="mw-page-title-main">MELAS syndrome</span> Medical condition

Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is one of the family of mitochondrial diseases, which also include MIDD, MERRF syndrome, and Leber's hereditary optic neuropathy. It was first characterized under this name in 1984. A feature of these diseases is that they are caused by defects in the mitochondrial genome which is inherited purely from the female parent. The most common MELAS mutation is mitochondrial mutation, mtDNA, referred to as m.3243A>G.

Myoclonic epilepsy refers to a family of epilepsies that present with myoclonus. When myoclonic jerks are occasionally associated with abnormal brain wave activity, it can be categorized as myoclonic seizure. If the abnormal brain wave activity is persistent and results from ongoing seizures, then a diagnosis of myoclonic epilepsy may be considered.

<span class="mw-page-title-main">MERRF syndrome</span> Medical condition

MERRF syndrome is a mitochondrial disease. It is extremely rare, and has varying degrees of expressivity owing to heteroplasmy. MERRF syndrome affects different parts of the body, particularly the muscles and nervous system. The signs and symptoms of this disorder appear at an early age, generally childhood or adolescence. The causes of MERRF syndrome are difficult to determine, but because it is a mitochondrial disorder, it can be caused by the mutation of nuclear DNA or mitochondrial DNA. The classification of this disease varies from patient to patient, since many individuals do not fall into one specific disease category. The primary features displayed on a person with MERRF include myoclonus, seizures, cerebellar ataxia, myopathy, and ragged red fibers (RRF) on muscle biopsy, leading to the disease's name. Secondary features include dementia, optic atrophy, bilateral deafness, peripheral neuropathy, spasticity, or multiple lipomata. Mitochondrial disorders, including MERRFS, may present at any age.

Juvenile myoclonic epilepsy (JME), also known as Janz syndrome or impulsive petit mal, is a form of hereditary, idiopathic generalized epilepsy, representing 5–10% of all epilepsy cases. Typically it first presents between the ages of 12 and 18 with myoclonic seizures. These events typically occur after awakening from sleep, during the evening or when sleep-deprived. JME is also characterized by generalized tonic–clonic seizures, and a minority of patients have absence seizures. It was first described by Théodore Herpin in 1857. Understanding of the genetics of JME has been rapidly evolving since the 1990s, and over 20 chromosomal loci and multiple genes have been identified. Given the genetic and clinical heterogeneity of JME some authors have suggested that it should be thought of as a spectrum disorder.

Unverricht–Lundborg disease is the most common form of an uncommon group of genetic epilepsy disorders called the progressive myoclonus epilepsies. It is caused due to a mutation in the cystatin B gene (CSTB). The disease is named after Heinrich Unverricht, who first described it in 1891, and Herman Bernhard Lundborg, who researched it in greater detail in 1901 and 1903. ULD onsets in children between the ages of 6 and 16; there are no known cases in which the person was older than 18. Most cases originate from the Baltic region of Europe, though many have been reported from countries in the Mediterranean.

Laforin, encoded by the EPM2A gene, is a phosphatase, with a carbohydrate-binding domain, which is mutated in patients with Lafora disease. It contains a dual specificity phosphatase domain (DSP) and a carbohydrate binding module subtype 20 (CBM20). Its physiological substrate has yet to be identified and the molecular mechanisms in which mutated laforin causes Lafora disease is unknown, though there has been progress made in the study by Ortolano et al. Laforin regulates autophagy via Mammalian target of rapamycin, which is impaired in Lafora disease.

Progressive Myoclonic Epilepsies (PME) are a rare group of inherited neurodegenerative diseases characterized by myoclonus, resistance to treatment, and neurological deterioration. The cause of PME depends largely on the type of PME. Most PMEs are caused by autosomal dominant or recessive and mitochondrial mutations. The location of the mutation also affects the inheritance and treatment of PME. Diagnosing PME is difficult due to their genetic heterogeneity and the lack of a genetic mutation identified in some patients. The prognosis depends largely on the worsening symptoms and failure to respond to treatment. There is no current cure for PME and treatment focuses on managing myoclonus and seizures through antiepileptic medication (AED).

<span class="mw-page-title-main">Cystatin B</span> Protein-coding gene in the species Homo sapiens

Cystatin-B is a protein that in humans is encoded by the CSTB gene.

<span class="mw-page-title-main">NHLRC1</span> Protein-coding gene in the species Homo sapiens

NHL repeat-containing protein 1 is a protein that in humans is encoded by the NHLRC1 gene.

Mitochondrially encoded tRNA phenylalanine also known as MT-TF is a transfer RNA which in humans is encoded by the mitochondrial MT-TF gene.

Mitochondrially encoded tRNA lysine also known as MT-TK is a transfer RNA which in humans is encoded by the mitochondrial MT-TK gene.

Myoclonic dystonia or Myoclonus dystonia syndrome is a rare movement disorder that induces spontaneous muscle contraction causing abnormal posture. The prevalence of myoclonus dystonia has not been reported, however, this disorder falls under the umbrella of movement disorders which affect thousands worldwide. Myoclonus dystonia results from mutations in the SGCE gene coding for an integral membrane protein found in both neurons and muscle fibers. Those suffering from this disease exhibit symptoms of rapid, jerky movements of the upper limbs (myoclonus), as well as distortion of the body's orientation due to simultaneous activation of agonist and antagonist muscles (dystonia).

<span class="mw-page-title-main">Northern epilepsy syndrome</span> Medical condition

Northern epilepsy syndrome (NE), or progressive epilepsy with mental retardation (EPMR), is a subtype of neuronal ceroid lipofuscinosis and a rare disease that is regarded as a Finnish heritage disease. Unlike most Finnish heritage diseases, this syndrome has been reported only in Finland. The disease is characterized by seizures in early childhood that progressively get worse until after puberty. Once the onset of seizures occurs, mental degradation is seen. This continues into adulthood, even after seizure frequency has decreased. The cause of the disease is a missense mutation on chromosome 8. The creation of a new protein occurs, and the lipid content of the brain is altered because of it. The ratio of the mutation carriers is 1:135. There is nothing that has been found to stop the progression of the disease, but symptomatic approaches, such as the use of benzodiazepines, have helped control seizures.

<span class="mw-page-title-main">Spinal muscular atrophy with progressive myoclonic epilepsy</span> Rare neurodegenerative disease whose symptoms include slowly progressive muscle wasting

Spinal muscular atrophy with progressive myoclonic epilepsy (SMA-PME), sometimes called Jankovic–Rivera syndrome, is a very rare neurodegenerative disease whose symptoms include slowly progressive muscle (atrophy), predominantly affecting proximal muscles, combined with denervation and myoclonic seizures. Only 12 known human families are described in scientific literature to have SMA-PME.

<span class="mw-page-title-main">Kohlschütter–Tönz syndrome</span> Medical condition

Kohlschütter–Tönz syndrome (KTS), also called amelo-cerebro-hypohidrotic syndrome, is a rare inherited syndrome characterized by epilepsy, psychomotor delay or regression, intellectual disability, and yellow teeth caused by amelogenesis imperfecta. It is a type A ectodermal dysplasia.

PRICKLE1-related progressive myoclonus epilepsy with ataxia is a very rare genetic disorder which is characterized by myoclonic epilepsy and ataxia.

GOSR2-related progressive myoclonus ataxia, also known as Progressive myoclonic epilepsy type 6 is a rare genetic type of progressive myoclonus ataxia which is characterized by progressive myoclonic epilepsy with an early onset which is associated with generalized tonic-clonic seizures, petit mal seizures, and drop attacks, variable degrees of scoliosis, areflexia, high levels of creatine kinase serum, and late-onset cognitive decline.

SLC13A5 citrate transporter disorder, or SLC13A5 Epilepsy, is a rare genetic spectrum disorder that presents with neurological symptoms. Symptoms include severe seizures, ataxia, dystonia, teeth hypoplasia, poor communication skills, difficulty standing or walking, as well as developmental delay. Other names associated with SLC13A5 Epilepsy include SLC13A5 Citrate Transporter Disorder, Citrate Transporter Disorder, SLC13A5 Deficiency, Early Infantile Epilepsy Encephalopathy 25 (EIEE25), Developmental Epilepsy Encephalopathy 25 (DEE25), and Kohlschutter-Tonz Syndrome (non-ROGDI).

References

  1. "Healthgrades Health Library".
  2. 1 2 3 4 Jansen, A.C.; Andermann, E. (21 February 2019) [Originally published 28 December 2007]. "Progressive Myoclonus Epilepsy, Lafora Type". In Adam, M.P.; Feldman, J.; Mirzaa, G.M.; Pagon, R.A.; Wallace, S.E.; Bean, L.J.H.; Gripp, K.W.; Amemiya, A. (eds.). GeneReviews. Seattle: University of Washington, Seattle. ISSN   2372-0697. PMID   20301563.
  3. "Association for Glycogen Storage Disease - Lafora Disease". 17 October 2018.
  4. 1 2 Ianzano L, Zhang J, Chan EM, Zhao XC, Lohi H, Scherer SW, Minassian BA (2005). "Lafora progressive Myoclonus Epilepsy mutation database - EPM2A and NHLRC1 (EPM2B) genes". Human Mutation. 26 (4): 397. doi: 10.1002/humu.9376 . PMID   16134145.
  5. James, William D.; Berger, Timothy G. (2006). Andrews' Diseases of the Skin: clinical Dermatology. Saunders Elsevier. ISBN   978-0-7216-2921-6.
  6. Ortolano, S.; Vieitez, I.; Agis-Balboa, R. C.; Spuch, C. (2014). "Loss of GABAergic cortical neurons underlies the neuropathology of Lafora disease". Molecular Brain. 7: 7. doi: 10.1186/1756-6606-7-7 . PMC   3917365 . PMID   24472629.
  7. Lafora, Gonzalo R.; Glueck, Bernard (December 1911). "Beitrag zur Histopathologie der myoklonischen Epilepsie: Bearbeitung des klinischen Teiles". Zeitschrift für die gesamte Neurologie und Psychiatrie (in German). 6 (1): 1–14. doi:10.1007/BF02863929. ISSN   0303-4194. S2CID   80976415.
  8. Kamm, Kurt. "Lafora disease research". www.canineepilepsy.co.uk. Retrieved 2017-11-07.
  9. Minassan, Berge A. (2000). "Lafora's Disease: Towards a Clinical, Pathologic, and Molecular Synthesis". Pediatric Neurology. 25 (1): 21–29. doi:10.1016/S0887-8994(00)00276-9. PMID   11483392.
  10. "Home". Chelsea's Hope Lafora Children Research Fund. April 4, 2024.
  11. "Lafora Overview".
  12. Lynch, David S.; Wood, Nicholas W.; Houlden, Henry (2016). "Late-onset Lafora disease with prominent parkinsonism due to a rare mutation in EPM2A". Neurology Genetics. 2 (5): e101. doi:10.1212/NXG.0000000000000101. PMC   4988466 . PMID   27574708.
  13. 1 2 "Lafora disease | Genetic and Rare Diseases Information Center (GARD) – an NCATS Program". rarediseases.info.nih.gov. Retrieved 2017-12-09.
  14. 1 2 3 4 5 "Lafora Progressive Myoclonus Epilepsy". Epilepsy Foundation. Retrieved 2017-12-12.
  15. "Lafora Disease". AGSD-UK. 2018-10-17. Retrieved 2021-11-28.
  16. "Lafora disease | Genetic and Rare Diseases Information Center (GARD) – an NCATS Program". rarediseases.info.nih.gov. Retrieved 2021-11-28.
  17. 1 2 3 4 Kecmanović, Miljana; Keckarević-Marković, Milica; Keckarević, Dušan; Stevanović, Galina; Jović, Nebojša; Romac, Stanka (2016-05-02). "Genetics of Lafora progressive myoclonic epilepsy: current perspectives". The Application of Clinical Genetics. 9: 49–53. doi: 10.2147/TACG.S57890 . ISSN   1178-704X. PMC   4859416 . PMID   27194917.
  18. 1 2 Reference, Genetics Home. "Lafora progressive myoclonus epilepsy". Genetics Home Reference. Retrieved 2017-12-12.
  19. 1 2 3 4 Turnbull, Julie; Striano, Pasquale; Genton, Pierre; Carpenter, Stirling; Ackerley, Cameron A.; Minassian, Berge A. (2016-09-01). "Lafora disease". Epileptic Disorders. 18 (Suppl 2): 38–62. doi:10.1684/epd.2016.0842. ISSN   1294-9361. PMC   5777303 . PMID   27702709.
  20. Ianzano, Leonarda; Zhang, Junjun; Chan, Elayne M.; Zhao, Xiao-Chu; Lohi, Hannes; Scherer, Stephen W.; Minassian, Berge A. (October 2005). "Lafora progressive Myoclonus Epilepsy mutation database-EPM2A and NHLRC1 (EPM2B) genes". Human Mutation. 26 (4): 397. doi: 10.1002/humu.9376 . ISSN   1098-1004. PMID   16134145.
  21. Mathieu, Cécile; de la Sierra-Gallay, Ines Li; Duval, Romain; Xu, Ximing; Cocaign, Angélique; Léger, Thibaut; Woffendin, Gary; Camadro, Jean-Michel; Etchebest, Catherine; Haouz, Ahmed; Dupret, Jean-Marie; Rodrigues-Lima, Fernando (26 August 2016). "Insights into Brain Glycogen Metabolism". Journal of Biological Chemistry. 291 (35): 18072–18083. doi: 10.1074/jbc.M116.738898 . PMC   5000057 . PMID   27402852.
  22. Wang, Wei; Lohi, Hannes; Skurat, Alexander V.; DePaoli-Roach, Anna A.; Minassian, Berge A.; Roach, Peter J. (2007-01-15). "Glycogen metabolism in tissues from a mouse model of Lafora disease". Archives of Biochemistry and Biophysics. 457 (2): 264–269. doi:10.1016/j.abb.2006.10.017. ISSN   0003-9861. PMC   2577384 . PMID   17118331.
  23. Sullivan, Mitchell A.; Nitschke, Silvia; Steup, Martin; Minassian, Berge A.; Nitschke, Felix (2017-08-11). "Pathogenesis of Lafora Disease: Transition of Soluble Glycogen to Insoluble Polyglucosan". International Journal of Molecular Sciences. 18 (8): 1743. doi: 10.3390/ijms18081743 . ISSN   1422-0067. PMC   5578133 . PMID   28800070.
  24. Ianzano, L; Zhao, XC; Minassian, BA; Scherer, SW (June 2003). "Identification of a novel protein interacting with laforin, the EPM2a progressive myoclonus epilepsy gene product". Genomics. 81 (6): 579–87. doi:10.1016/S0888-7543(03)00094-6. ISSN   0888-7543. PMID   12782127.
  25. Gentry, Matthew S.; Worby, Carolyn A.; Dixon, Jack E. (2005-06-14). "Insights into Lafora disease: Malin is an E3 ubiquitin ligase that ubiquitinates and promotes the degradation of laforin". Proceedings of the National Academy of Sciences of the United States of America. 102 (24): 8501–8506. doi: 10.1073/pnas.0503285102 . ISSN   0027-8424. PMC   1150849 . PMID   15930137.
  26. Turnbull, Julie; Girard, Jean-Marie; Lohi, Hannes; Chan, Elayne M.; Wang, Peixiang; Tiberia, Erica; Omer, Salah; Ahmed, Mushtaq; Bennett, Christopher (September 2012). "Early-onset Lafora body disease". Brain. 135 (9): 2684–2698. doi:10.1093/brain/aws205. ISSN   0006-8950. PMC   3437029 . PMID   22961547.
  27. 1 2 3 Nitschke, Felix; Sullivan, Mitchell A; Wang, Peixiang; Zhao, Xiaochu; Chown, Erin E; Perri, Ami M; Israelian, Lori; Juana-López, Lucia; Bovolenta, Paola (July 2017). "Abnormal glycogen chain length pattern, not hyperphosphorylation, is critical in Lafora disease". EMBO Molecular Medicine. 9 (7): 906–917. doi:10.15252/emmm.201707608. ISSN   1757-4676. PMC   5494504 . PMID   28536304.
  28. RESERVED, INSERM US14-- ALL RIGHTS. "Orphanet: Lafora disease". www.orpha.net. Retrieved 2021-11-28.{{cite web}}: CS1 maint: numeric names: authors list (link)
  29. Striano, Pasquale; Zara, Federico; Turnbull, Julie; Girard, Jean-Marie; Ackerley, Cameron A.; Cervasio, Mariarosaria; De Rosa, Gaetano; Del Basso-De Caro, Maria Laura; Striano, Salvatore (February 2008). "Typical progression of myoclonic epilepsy of the Lafora type: a case report". Nature Clinical Practice Neurology. 4 (2): 106–111. doi:10.1038/ncpneuro0706. ISSN   1745-8358. PMID   18256682. S2CID   19653919.
  30. 1 2 3 "Lafora Progressive Myoclonus Epilepsy". Epilepsy Foundation. Retrieved 2017-12-13.
  31. Lafora's disease at Who Named It?
  32. Rai, Anupama; Mishra, Rohit; Ganesh, Subramaniam (2017-12-15). "Suppression of leptin signaling reduces polyglucosan inclusions and seizure susceptibility in a mouse model for Lafora disease". Human Molecular Genetics. 26 (24): 4778–4785. doi: 10.1093/hmg/ddx357 . ISSN   0964-6906. PMID   28973665.
  33. "Researchers Coordinate Efforts to Find Cure for Lafora Disease". Epilepsy Foundation. Retrieved 2017-12-13.
  34. "Chelsea's Hope Lafora Children Research Fund - Chelsea Hope". Chelsea's Hope Lafora Children Research Fund. Retrieved 2024-04-04.
  35. A Day in Chelsea's Life | Living with Lafora Disease | Lafora Heroes . Retrieved 2024-04-04 via www.youtube.com.