Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0013421 (dystonia)
 8,418 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Paroxysmal exercise-induced dyskinesia (PED) can occur in isolation or in association with epilepsy, but the genetic causes and pathophysiological mechanisms are still poorly understood. We performed a clinical evaluation and genetic analysis in a five-generation family with co-occurrence of PED and epilepsy (n = 39), suggesting that this combination represents a clinical entity. Based on a whole genome linkage analysis we screened SLC2A1, encoding the glucose transporter of the blood-brain-barrier, GLUT1 and identified heterozygous missense and frameshift mutations segregating in this and three other nuclear families with a similar phenotype. PED was characterized by choreoathetosis, dystonia or both, affecting mainly the legs. Predominant epileptic seizure types were primary generalized. A median CSF/blood glucose ratio of 0.52 (normal >0.60) in the patients and a reduced glucose uptake by mutated transporters compared with the wild-type as determined in Xenopus oocytes confirmed a pathogenic role of these mutations. Functional imaging studies implicated alterations in glucose metabolism in the corticostriate pathways in the pathophysiology of PED and in the frontal lobe cortex in the pathophysiology of epileptic seizures. Three patients were successfully treated with a ketogenic diet. In conclusion, co-occurring PED and epilepsy can be due to autosomal dominant heterozygous SLC2A1 mutations, expanding the phenotypic spectrum associated with GLUT1 deficiency and providing a potential new treatment option for this clinical syndrome.
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PMID:Paroxysmal exercise-induced dyskinesia and epilepsy is due to mutations in SLC2A1, encoding the glucose transporter GLUT1. 1857 46

Transport of glucose from the bloodstream across the blood-brain barrier to the central nervous system is facilitated by glucose transport protein type 1 (GLUT1), the first member of the solute carrier family 2 (SLC2). Heterozygous mutations in the GLUT1/SLC2A1 gene, occurring de novo or inherited as an autosomal dominant trait, result in cerebral energy failure and a clinical condition termed GLUT1-deficiency syndrome (GLUT1-DS). Clinical features usually comprise motor and mental developmental delay, seizures with infantile onset, deceleration of head growth often resulting in acquired microcephaly, and a movement disorder with ataxia, dystonia, and spasticity. Subsequent to the delineation of this classic phenotype the variability of signs and symptoms in GLUT1-DS is being recognized. Patients with (i) carbohydrate-responsive symptoms, with (ii) predominant ataxia or dystonia, but without seizures, and with (iii) paroxysmal exertion-induced dyskinesia and seizures have been reported. Common laboratory hallmark in all phenotypes is the reduced glucose level in cerebrospinal fluid with lowered CSF-to-blood glucose ratio. Treatment with a ketogenic diet results in marked improvement of seizures and movement disorders.
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PMID:The expanding phenotype of GLUT1-deficiency syndrome. 1930 21

Paroxysmal dyskinesias (PDs) are a heterogeneous group of disorders characterized by sudden attacks of involuntary movements that are mostly a combination of dystonia, chorea, athetosis, and ballism. They can sometimes be symptomatic, but usually an underlying cerebral lesion is not present. Most PDs have a genetic background and are divided into kinesigenic, nonkinesigenic, and exercise-induced forms. Recently, the first genes have been identified for paroxysmal nonkinesigenic dyskinesia (MR1) and paroxysmal exercise-induced dyskinesia (PED) (SLC2A1). Whereas the function of the MR-1 protein and the pathophysiology are still poorly understood, mutations in SLC2A1 and their functional characterization predict a reduced transport of glucose across the blood-brain barrier as the underlying mechanism of PED. A locus on chromosome 16 has been described for the kinesigenic forms, but the underlying genetic alterations are unknown. This review summarizes clinical symptoms of the PDs, imaging findings, therapeutic options, and the pathophysiologic background.
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PMID:Genetics of paroxysmal dyskinesias. 1934 9

Presently, 17 distinct monogenic primary dystonias referred to as dystonias 1- 4, 5a,b, 6-8, 10-13 and 15-18 (loci DYT 1-4, 5a,b, 6-8, 10-13, 15-18) have been recognized. Twelve forms are inherited as autosomal dominant, four as autosomal recessive and one as an X-linked recessive trait. Three additional autosomal dominant forms (DYT9, DYT19 and DYT20) might exist based on linkage mapping to regions apparently different from, yet in close proximity to or overlapping with the known loci DYT18, DYT10 and DYT8. Clinically, this group of movement disorders includes pure dystonias and dystonia plus syndromes. In addition, dyskinesias (paroxysmal dystonias), although phenotypically distinct from classical dystonias, are discussed within this group. In pure dystonias, dystonia is occasionally accompanied by tremor. In dystonia plus syndromes, dystonia as the prominent sign concurs with other movement abnormalities such as myoclonus and parkinsonism. In the dyskinesias, dystonia occurs as a paroxysmal sign in association with other movement anomalies and sometimes seizures. While gross neuropathological changes are absent in most primary dystonias, including the paroxysmal forms, striking morphological alterations are found in some, such as in the X-linked dystonia-parkinsonism syndrome (DYT3). Neuropathological findings at the microscopic level have also been reported in several cases of dystonia 1 and 5, both of which were previously thought to be morphologically normal. One locus, DYT14 had been erroneously assigned, by linkage mapping, in a family with dystonia 5. There are two forms of dystonia 5, one autosomal dominant and one autosomal recessive. These forms are designated here as dystonia 5a and dystonia 5b (DYT5a, DYT5b), respectively. The disease gene has been identified in 10 primary dystonias, seven autosomal dominant (TOR1A/DYT1, GCH1/DYT5a, THAP1/DYT6, PNKD1/MR-1/DYT8, SGCE/DYT11, ATP1A3/DYT12 and SLC2A1/DYT18), two autosomal recessive (TH/DYT5b and PRKRA/DYT16) and one X-chromosomal recessive (TAF1/DYT3). This article summarizes all known aspects on each of the monogenic primary dystonias, including phenotype, neuropathology, imaging, inheritance, mapping, molecular genetics, molecular pathology, animal models and treatment. Suggestions for the diagnostic procedure in primary dystonias are given. Although much is now known about the molecular basis of primary dystonias, treatment of patients is still mainly symptomatic. The only exceptions are dystonias 5a and 5b with their excellent long-term response to L-dopa substitution.
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PMID:The monogenic primary dystonias. 1957 24

The dystonias comprise a heterogeneous group of movement disorders. In contrast to the frequent sporadic forms, a variety of rare familial forms are caused by genetic mutations with mendelian inheritance. In recent years, significant progress has been made with regard to the identification of genes causing dystonia, and to the molecular pathophysiology underlying dystonic symptoms. Currently, 18 gene loci have been described causing primary dystonia, dystonia-plus syndromes or paroxysmal dystonia. The most frequent form of inherited dystonia, according to current knowledge, is early-onset generalized DYT1 dystonia, caused by a deletion of three basepairs, GAG, in the DYT1 (TOR1A) gene. It is thought that the protein encoded by this gene, torsinA, participates in association of the endoplasmatic reticulum and the nuclear envelope with the cytoskeleton and hereby might influence the reaction of cells to various stresses and/or the development of specific neuronal populations involved in movement control in the brain. Other genes which have only recently been identified include: THAP1, causing adolescent-onset primary dystonia of mixed type (DYT6); ATP1A3, responsible for Rapid-Onset Dystonia-Parkinsonism (RDP, DYT12); PRKRA, causing young-onset dystonia-parkinsonism (DYT16); and SLC2A1, causing paroxysmal exertion-induced dystonia with haemolytic anemia (DYT18). Further, five other loci for primary dystonia (DYT2, DYT4, DYT7, DYT13 and DYT17) have been identified, for which the causative genes remain to be discovered.
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PMID:[Genetics of dystonia]. 1968 89

Glucose transporter 1 deficiency syndrome (GLUT1-DS) is due to heterozygous mutation of the glucose transporter type 1 gene (GLUT1/SLC2A1). GLUT1-DS is characterized by movement disorders, including paroxysmal exercise-induced dystonia (PED), as well as seizures, mental retardation and hypoglycorrhachia. Tremor was recently shown to be part of the phenotype, but its clinical and electrophysiological features have not yet been described in detail, and GLUT1 tremor reports are rare. We describe two patients, a young woman and her mother, who were referred to us for tremor. We also systematically review published cases of GLUT1-DS with tremor (14 cases, including ours), focusing on clinical features. In most cases (10/14), the tremor, which involved the limbs and voice, fulfilled clinical criteria for dystonic tremor (DT), occurring in body areas affected by dystonia. Tremor was the only permanent symptom in 2 cases. Recordings, reported here for the first time, showed an irregular 6- to 8.5-Hz tremor compatible with DT in our two patients. These findings show that tremor, and particularly DT, may be a presenting symptom of GLUT1-DS. Patients who present with dystonic tremor, with or without mental retardation, seizures, movement disorders and/or a family history, should therefore be screened for GLUT1-DS.
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PMID:Dystonic tremor caused by mutation of the glucose transporter gene GLUT1. 2122 16

Paroxysmal exercise-induced dyskinesia (PED) is a rare form of dystonia induced by prolonged exercise, usually involving lower limbs. PED has been recently described as a possible clinical manifestation of mutations of SLC2A1 gene, encoding for the glucose transport GLUT-1. We report a case of a young woman with a mild form of PED associated with self-limiting partial epilepsy. She carries a novel sporadic heterozygous mutation of the SLC2A1 gene. Diagnostic difficulties and possible treatment with carbamazepine are discussed.
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PMID:Paroxysmal exercise-induced dyskinesia with self-limiting partial epilepsy: a novel GLUT-1 mutation with benign phenotype. 2153 Mar 57

Glucose transporter type 1 deficiency syndrome (GLUT1DS) is a treatable condition resulting from impaired glucose transport into the brain. The classical presentation is with infantile-onset epilepsy and severe developmental delay. Non-classical phenotypes with movement disorders and early-onset absence epilepsy are increasingly recognized and the clinical spectrum is expanding. The hallmark is hypoglycorrhachia (cerebrospinal fluid [CSF] glucose<2.2 mmol/l) in the presence of normoglycaemia with a CSF/blood glucose ratio of less than 0.4. GLUT1DS is due to a mutation in the solute carrier family 2, member 1 gene (SLC2A1). We present five individuals (four males, one female), all of whom had a mild phenotype, highlighting the importance of considering this diagnosis in unexplained neurological disorders associated with mild learning difficulties, subtle motor delay, early-onset absence epilepsy, fluctuating gait disorders, and/or dystonia. The mean age at diagnosis was 8 years 8 months. This paper also shows phenotypical parallels between GLUT1DS and paroxysmal exertion-induced dyskinesia.
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PMID:Milder phenotypes of glucose transporter type 1 deficiency syndrome. 2164 51

Primary monogenic forms of dystonia manifest solely or mainly with dystonia; they have been linked to a number of genes and loci and assigned "DYT" numbers. The pure dystonia syndrome early-onset primary dystonia (DYT1) manifests with dominantly-inherited generalized dystonia, often with focal onset in a limb. DYT1 is caused by a GAG deletion in the TOR1A gene. Mutations in the THAP1 gene cause DYT6, a form of pure dystonia that primarily involves cranio-cervical and upper limb muscles. Patients with the dystonia plus syndrome DYT5 display levodopa-responsive dystonia sometimes associated with tremor or parkinsonism (DYT5a, mutations in GCH1); a more severe phenotype with psychomotor involvement can be seen in recessive forms (DYT5b with TH mutations, SPR-deficiency syndrome). Other forms of dystonia plus syndromes include myoclonic dystonia (DYT11) and rapid-onset dystonia-parkinsonism (DYT12). Finally, paroxysmal exertion-induced dystonia (DYT18, GLUT1 deficiency) is caused by mutations in the SLC2A1 gene (DYT9 and DYT18). It is part of the paroxysmal dystonia group and manifests with paroxystic movements sometimes associated with seizures and psychomotor developmental delay.
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PMID:Overview of primary monogenic dystonia. 2216 20

Glucose transporter type 1 deficiency syndrome is characterized by infantile onset seizures, development delay, movement disorders, and acquired microcephaly. The phenotype includes allelic variants such as intermittent ataxia, choreoathetosis, dystonia, and alternating hemiplegia of childhood with or without epilepsy. Dystonias involve allelic variants of glucose transporter type 1 deficiency syndrome. Three Chinese patients presented with paroxysmal behavioral disturbance, weakness, ataxia (especially after fasting), and exercise intolerance. Electroencephalogram findings did not correlate with clinical manifestations. Cranial magnetic resonance imaging produced normal results or mild hypomyelination. Hypoglycorrhachia was evident in all cases. Cerebrospinal fluid glucose ranged from 1.63-2.45 mmol/L. Erythrocyte 3-O-methyl-d-glucose uptake was decreased to 58% in patient 1. Three SLC2A1 disease-causing mutations (761delA, P383H, and R400C) were observed. No patient tolerated ketogenic diets. Two patients responded to frequent meals with snacks. Cerebrospinal fluid evaluation constitutes the diagnostic testing permitting early treatment of glucose transporter type 1 deficiency syndrome. Early diagnosis and treatment improve prognoses.
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PMID:Allelic variations of glut-1 deficiency syndrome: the chinese experience. 2270 13


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