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Boileau S, Vuillaume I, Sablonnière B, Marignier S, Des Portes V, Vallée L, Auvin S. 'Absence of T378N mutation of ATP1A2 gene in five patients with alternating hemiplegia of childhood'. Dev Med Child Neurol 2008; 50:879-80. [PMID: 18811707 DOI: 10.1111/j.1469-8749.2008.03111.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Terayama R, Bando Y, Murakami K, Kato K, Kishibe M, Yoshida S. Neuropsin promotes oligodendrocyte death, demyelination and axonal degeneration after spinal cord injury. Neuroscience 2007; 148:175-87. [PMID: 17629414 DOI: 10.1016/j.neuroscience.2007.05.037] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Revised: 04/23/2007] [Accepted: 05/16/2007] [Indexed: 01/08/2023]
Abstract
Previous studies indicated that the expression of neuropsin, a serine protease, is induced in mature oligodendrocytes after injury to the CNS. The pathophysiology of spinal cord injury (SCI) involves primary and secondary mechanisms, the latter contributing further to permanent losses of function. To explore the role of neuropsin after SCI, histochemical and behavioral analyses were performed in wild-type (WT) and neuropsin-deficient (neuropsin(-/-)) mice using a crush injury model, a well-characterized and consistently reproducible model of SCI. In situ hybridization revealed that neuropsin mRNA expression was induced in the spinal cord white matter from WT mice after crush SCI, peaking at day 4. Neuropsin(-/-) mice showed attenuated demyelination, oligodendrocyte death, and axonal damage after SCI. Although axonal degeneration in the corticospinal tract was obvious caudal to the lesion site in both strains of mice after SCI, the number of surviving nerve fibers caudal to the lesion was significantly larger in neuropsin(-/-) mice than WT mice. Behavioral analysis revealed that the recovery at days 10-42 was significantly improved in neuropsin(-/-) mice compared with WT mice in spite of the severe initial hindlimb impairments due to SCI in both strains. These observations suggest that neuropsin is involved in the secondary phase of the pathogenesis of SCI mediated by demyelination, oligodendrocyte death, and axonal degeneration.
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Vahedi K, Kubis N, Boukobza M, Arnoult M, Massin P, Tournier-Lasserve E, Bousser MG. COL4A1 mutation in a patient with sporadic, recurrent intracerebral hemorrhage. Stroke 2007; 38:1461-4. [PMID: 17379824 DOI: 10.1161/strokeaha.106.475194] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Recently COL4A1, a gene encoding the type IV collagen alpha1 chain, has been found to be involved in families with autosomal-dominant porencephaly and infantile hemiparesis. In addition to neonatal stroke, some family members had experienced, during adulthood, spontaneous intracerebral hemorrhages (ICHs) and leukoencephalopathy, suggestive of underlying small-vessel disease of the brain. We now report a patient with sporadic, recurrent ICHs and a novel COL4A1 mutation. METHODS We performed a clinical and genetic study of a 25-year-old-patient with an 8-year history of recurrent ICHs. RESULTS This young, normotensive patient with a history of infantile hemiparesis had experienced, since the age of 17, recurrent, spontaneous, deep ICHs occurring during sports activities. He became severely disabled. Brain magnetic resonance imaging showed ventricular enlargement, diffuse white-matter abnormalities, and newly appearing, deep, silent microbleeds. Extensive investigations found no cause. There was no family history of stroke or infantile hemiparesis. A novel COL4A1 mutation (G805R) was identified. CONCLUSIONS The clinical spectrum of COL4A1 mutations includes recurrent ICHs in association with diffuse leukoencephalopathy in young adults, even in the absence of a family history of infantile hemiparesis or ICH. In addition to birth trauma, anticoagulant use, and head trauma previously reported, sports activities may be a precipitating factor of ICHs in persons with COL4A1 mutations.
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Low N, Singleton A. Establishing the genetic heterogeneity of familial hemiplegic migraine. Brain 2007; 130:312-3. [PMID: 17235123 DOI: 10.1093/brain/awl381] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Thomsen LL, Kirchmann M, Bjornsson A, Stefansson H, Jensen RM, Fasquel AC, Petursson H, Stefansson M, Frigge ML, Kong A, Gulcher J, Stefansson K, Olesen J. The genetic spectrum of a population-based sample of familial hemiplegic migraine. Brain 2006; 130:346-56. [PMID: 17142831 DOI: 10.1093/brain/awl334] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Familial hemiplegic migraine (FHM) is a rare subtype of migraine with aura and transient hemiplegia. FHM mutations are known in three genes, the CACNA1A (FHM1) gene, the ATP1A2 (FHM2) and the SCN1A (FHM3) gene and seem to have an autosomal-dominant mode of inheritance. The aim of this study was to search for FHM mutations in FHM families identified through a screen of the Danish population of 5.2 million people. FHM patients were diagnosed according to the International Classification of Headache Disorders and all FHM patients had a physical and neurological examination by a physician. A total of 147 FHM patients from 44 different families were identified; 43 FHM families participated in this study. Linkage analysis of these families shows clear linkage to the FHM locus (FHM1) on chromosome 19, supportive linkage to the FHM2 locus whereas no linkage was found to the FHM3 locus. Furthermore, we sequenced all exons and promoter regions of the CACNA1A and ATP1A2 genes and screened for the Q1489K mutation in the SCN1A gene. CACNA1A gene mutations were identified in three of the FHM families, two known FHM mutations, R583Q and T666M and one novel C1369Y mutation. Three FHM families were identified with novel mutations in the ATP1A2 gene; a family with a V138A mutation, a family with a R202Q mutation and a family with a R763C mutation. None of the Danish FHM families have the Q1489K mutation in the SCN1A gene. Our study shows that only 14% (6/42) of FHM families in the general Danish population have exonic FHM mutations in the CACNA1A or ATP1A2 gene. The families we identified with FHM mutations in the CACNA1A and ATP1A2 genes were extended, multiple affected families whereas the remaining FHM families were smaller. The existence of many small families in the Danish FHM cohort may reflect less bias in FHM family ascertainment and/or more locus heterogeneity than described previously.
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de Vries B, Haan J, Stam AH, Vanmolkot KRJ, Stroink H, Laan LAEM, Gill DS, Pascual J, Frants RR, van den Maagdenberg AMJM, Ferrari MD. Alternating hemiplegia of childhood: no mutations in the glutamate transporter EAAT1. Neuropediatrics 2006; 37:302-4. [PMID: 17236110 DOI: 10.1055/s-2006-924609] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Alternating hemiplegia of childhood (AHC) is a severe brain disorder, mainly characterised by episodes of hemiplegia, progressive mental retardation, and other severe paroxysmal and permanent neurological symptoms. Clinically and genetically, there is some overlap with sporadic (SHM) and familial (FHM) hemiplegic migraine, a severe monogenic subtype of migraine. Although no mutations were detected in the FHM1 CACNA1A and FHM2 ATP1A2 genes in sporadic AHC patients, a mutation was found in the FHM2 ATP1A2 gene in a family with AHC. Recently, a missense mutation was found in the SLC1A3 gene that encodes the glutamate transporter EAAT1, in a patient with alternating hemiplegia, episodic ataxia, seizures, and headache. Because of the remarkable clinical similarities and the potential role of glutamate in AHC, we analysed six sporadic patients with AHC for mutations in the SLC1A3 gene. No mutations were found. The SLC1A3 EAAT1 glutamate transporter gene does not seem to be involved in the pathogenesis of AHC.
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Blostein R, Segall L, Gargus JJ. [ATP1A2: a key player in familial hemiplegic migraine]. Med Sci (Paris) 2006; 22:341-3. [PMID: 16597394 DOI: 10.1051/medsci/2006224341] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Vanmolkot KRJ, Kors EE, Turk U, Turkdogan D, Keyser A, Broos LAM, Kia SK, van den Heuvel JJMW, Black DF, Haan J, Frants RR, Barone V, Ferrari MD, Casari G, Koenderink JB, van den Maagdenberg AMJM. Two de novo mutations in the Na,K-ATPase gene ATP1A2 associated with pure familial hemiplegic migraine. Eur J Hum Genet 2006; 14:555-60. [PMID: 16538223 DOI: 10.1038/sj.ejhg.5201607] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Familial hemiplegic migraine (FHM) is a rare autosomal dominantly inherited subtype of migraine, in which hemiparesis occurs during the aura. The majority of the families carry mutations in the CACNA1A gene on chromosome 19p13 (FHM1). About 20% of FHM families is linked to chromosome 1q23 (FHM2), and has mutations in the ATP1A2 gene, encoding the alpha2-subunit of the Na,K-ATPase. Mutation analysis in a Dutch and a Turkish family with pure FHM revealed two novel de novo missense mutations, R593W and V628M, respectively. Cellular survival assays support the hypothesis that both mutations are disease-causative. The identification of the first de novo mutations underscores beyond any doubt the involvement of the ATP1A2 gene in FHM2.
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Abstract
Hemiplegic migraine is a rare subtype of migraine with aura associated with transient hemiplegia. The weakness is caused by motor aura. Hemiplegic migraine is the only headache syndrome associated with known genetic mutations and serves as a model for understanding more common varieties of migraine. Because the phenotype includes striking yet transient neurological signs and symptoms, it is imperative that clinicians know the differential diagnosis to rule out possible secondary etiologies when treating patients with hemiplegic spells. Hemiplegic migraine occurs with equal prevalence in either a sporadic or familial form differentiated only by family history. Thus far, treatment trials are anecdotal, although verapamil and acetazolamide have shown promise.
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Blumkin L, Watemberg N, Lev D, Malinger G, Luckman Y, Ben-Zeev B, Lerman-Sagie T. Nonprogressive familial leukoencephalopathy with porencephalic cyst and focal seizures. J Child Neurol 2006; 21:145-8. [PMID: 16566879 DOI: 10.1177/08830738060210021701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Two siblings with a similar white-matter disease but different clinical symptoms are described. The first sibling suffers from nonprogressive spastic hemiparesis secondary to a congenital periventricular porencephalic cyst. Her brother has focal epilepsy. On magnetic resonance imaging, both patients show diffuse white-matter involvement predominantly of the posterior periventricular area. We suggest that this is a familial white-matter disorder with minimal symptoms and no progression in early childhood.
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Dreier JP, Jurkat-Rott K, Petzold GC, Tomkins O, Klingebiel R, Kopp UA, Lehmann-Horn F, Friedman A, Dichgans M. Opening of the blood-brain barrier preceding cortical edema in a severe attack of FHM type II. Neurology 2006; 64:2145-7. [PMID: 15985592 DOI: 10.1212/01.wnl.0000176298.63840.99] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The authors report a patient with familial hemiplegic migraine type II who developed a long-lasting attack including fever, right-sided hemiplegia, aphasia, and coma. Quantitative analysis of early gadolinium-enhanced MRI revealed a mild but significant left-hemispheric blood-brain barrier (BBB) opening limited to the cortex and preceding cortical edema. The findings suggest that the delayed cortical edema was vasogenic in the severe migraine aura variant of this ATP1A2 mutation carrier.
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Dichgans M, Herzog J, Freilinger T, Wilke M, Auer DP. 1H-MRS alterations in the cerebellum of patients with familial hemiplegic migraine type 1. Neurology 2005; 64:608-13. [PMID: 15728280 DOI: 10.1212/01.wnl.0000151855.98318.50] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND About 20% of patients with familial hemiplegic migraine (FHM) develop progressive cerebellar signs. Genetic studies have established an association with mutations in the CACNA1A gene. However, the mechanisms underlying cerebellar involvement are largely unknown. OBJECTIVE To use proton MR spectroscopy (1H-MRS) to investigate metabolic alterations in the cerebellum as well as cortical regions known to be involved in the propagation of migraine aura. METHODS Fifteen CACNA1A mutation carriers from three FHM families and 17 healthy control subjects were studied. Eleven patients had clinical signs of cerebellar involvement. LCModel fits were used to estimate absolute concentrations of N-acetyl aspartate (NAA), myo-inositol (mI), glutamate (Glu), choline-containing compounds, total creatine, and lactate in the superior cerebellar vermis (SCV), parietal cortex, and occipital cortex. To control for atrophy effects, automated image segmentation was performed using SPM99. The brain parenchyma fraction (BPF) was determined for all three regions. RESULTS Compared with controls, the brain parenchyma fraction (BPF), NAA, and Glu were significantly reduced and mI was significantly elevated in the SCV of patients with FHM. In contrast, no metabolite alterations were found in supratentorial regions. BPF and NAA in the SCV significantly correlated with cerebellar scores, in particular, gait ataxia. CONCLUSIONS The findings suggest that there is a regionally distinct neuronal impairment in the superior cerebellar vermis that exceeds macroscopic tissue loss. Correlations with clinical scores emphasize the functional relevance of localized atrophy (brain parenchyma fraction) and N-acetyl aspartate levels. These measures may be useful to monitor disease progression. The observed reduction in glutamate may in part reflect impaired glutamatergic neurotransmission.
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Capendeguy O, Horisberger JD. Functional effects of Na+,K+-ATPase gene mutations linked to familial hemiplegic migraine. Neuromolecular Med 2005; 6:105-16. [PMID: 15970628 DOI: 10.1385/nmm:6:2-3:105] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2004] [Revised: 09/17/2004] [Accepted: 09/20/2004] [Indexed: 11/11/2022]
Abstract
Familial hemiplegic migraine type 2, an autosomal dominant form of migraine with aura, has been associated with four distinct mutations in the alpha2-subunit of the Na+,K+-ATPase. We have introduced these mutations in the alpha2-subunit of the human Na+,K+-ATPase and the corresponding mutations in the Bufo marinus alpha1-subunit and studied these mutants by expression in Xenopus oocyte. Metabolic labeling studies showed that the mutants were synthesized and associated with the beta-subunit, except for the alpha2HW887R mutant, which was poorly synthesized, and the alpha1BW890R, which was partially retained in the endoplasmic reticulum. [3H]ouabain binding showed the presence of the alpha2HR689Q and alpha2HM731T at the membrane, whereas the alpha2HL764P and alpha2HW887R could not be detected. Functional studies with the mutants of the B. marinus Na+,K+-ATPase showed a reduced or abolished electrogenic activity and a low K+ affinity for the alpha1BW890R mutant. Through different mechanisms, all these mutations result in a strong decrease of the functional expression of the Na+,K+-pump. The decreased activity in alpha2 isoform of the Na+,K+-pump expressed in astrocytes seems an essential component of hemiplegic migraine pathogenesis and may be responsible for the cortical spreading depression, which is one of the first events in migraine attacks.
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Verdu A, Cazorla MR, Moreno JC, Casado LF. Prenatal stroke in a neonate heterozygous for factor V Leiden mutation. Brain Dev 2005; 27:451-4. [PMID: 16122636 DOI: 10.1016/j.braindev.2004.10.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2004] [Revised: 10/27/2004] [Accepted: 10/27/2004] [Indexed: 10/26/2022]
Abstract
The authors report an infant with congenital hemiplegia associated to heterozygosity for factor V Leiden. Prenatal stroke in the left cerebral hemisphere was diagnosed by ultrasonography at the 28th week of pregnancy, and followed up until birth. Although neonatal neurologic examination was normal, a moderate right hemiparesis developed along the 1st months of life. Coagulation studies performed in the neonatal period and at the age of 18 months revealed activated protein C resistance due to factor V Leiden mutation (R506Q). There are some previous reports of stroke associated to this mutation in near or at term neonates, but to our knowledge this is the stroke detected at the most early stage of fetal development.
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Dichgans M, Freilinger T, Eckstein G, Babini E, Lorenz-Depiereux B, Biskup S, Ferrari MD, Herzog J, van den Maagdenberg AMJM, Pusch M, Strom TM. Mutation in the neuronal voltage-gated sodium channel SCN1A in familial hemiplegic migraine. Lancet 2005; 366:371-7. [PMID: 16054936 DOI: 10.1016/s0140-6736(05)66786-4] [Citation(s) in RCA: 556] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Familial hemiplegic migraine is an autosomal dominant severe subtype of migraine with aura characterised by some degree of hemiparesis during the attacks. So far, mutations in two genes regulating ion translocation-CACNA1A and ATP1A2-have been identified in pedigrees with this disease. METHODS To identify additional genes for familial hemiplegic migraine, we did a genome-wide linkage analysis of two disease pedigrees without mutations in CACNA1A and ATP1A2. Ion channel genes in the candidate interval were analysed for mutations, and the functional consequences of the recorded sequence alteration were determined. FINDINGS We identified a novel locus for familial hemiplegic migraine on chromosome 2q24. Sequencing of candidate genes in this region revealed a heterozygous missense mutation (Gln1489Lys) in the neuronal voltage-gated sodium channel gene SCN1A, mutations of which have been associated with epilepsy. This same mutation was present in three families with familial hemiplegic migraine. It results in a charge-altering aminoacid exchange in the so-called hinged-lid domain of the protein, which is critical for fast inactivation of the channel. Whole-cell recordings in transiently transfected tsA201 cells expressing the highly homologous SCN5A sodium channel showed that the mutation induces a two-fold to four-fold accelerated recovery from fast inactivation without altering any of the other channel parameters investigated. INTERPRETATION Dysfunction of the neuronal sodium channel SCN1A can cause familial hemiplegic migraine. Our findings have implications for the understanding of migraine aura. Moreover, our study reinforces the molecular links between migraine and epilepsy, two common paroxysmal disorders.
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Segall L, Mezzetti A, Scanzano R, Gargus JJ, Purisima E, Blostein R. Alterations in the alpha2 isoform of Na,K-ATPase associated with familial hemiplegic migraine type 2. Proc Natl Acad Sci U S A 2005; 102:11106-11. [PMID: 16037212 PMCID: PMC1178013 DOI: 10.1073/pnas.0504323102] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A number of missense mutations in the Na,K-ATPase alpha2 catalytic subunit have been identified in familial hemiplegic migraine with aura. Two alleles (L764P and W887R) showed loss-of-function, whereas a third (T345A) is fully functional but with altered Na,K-ATPase kinetics. This study describes two additional mutants, R689Q and M731T, originally identified by Vanmolkot et al. [Vanmolkot, K. R., et al. (2003) Ann. Neurol. 54, 360-366], which we show here to also be functional and kinetically altered. Both mutants have reduced catalytic turnover and increased apparent affinity for extracellular K(+). For both R689Q and M731T, sensitivity to vanadate inhibition is decreased, suggesting that the steady-state E(1) <==> E(2) poise of the enzyme is shifted toward E(1). Whereas the K'(ATP) is not affected by the R689Q replacement, the M731T mutant has an increase in apparent affinity for ATP. Analysis of the structural changes effected by T345A, R689Q, and M731T mutations, based on homologous replacements in the known crystal structure of the sarcoplasmic reticulum Ca-ATPase, provides insights into the molecular bases for the kinetic alterations. It is suggested that the disease phenotype is the consequence of lowered molecular activity of the alpha2 pump isoform due to either decreased K(+) affinity (T345A) or catalytic turnover (R689Q and M731T), thus causing a delay in extracellular K(+) clearance and/or altered localized Ca(2+) handling/signaling secondary to reduced activity in colocalized Na(+)/Ca(2+) exchange.
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Jen JC, Wan J, Palos TP, Howard BD, Baloh RW. Mutation in the glutamate transporter EAAT1 causes episodic ataxia, hemiplegia, and seizures. Neurology 2005; 65:529-34. [PMID: 16116111 DOI: 10.1212/01.wnl.0000172638.58172.5a] [Citation(s) in RCA: 241] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Transporters, ion pumps, and ion channels are membrane proteins that regulate selective permeability and maintain ionic gradients across cell membranes. Mutations in CACNA1A encoding a neuronal calcium channel and ATP1A2 encoding an ion pump cause episodic ataxia, hemiplegic migraine, and seizures. Mutant gene products of both CACNA1A and ATP1A2 may affect neurotransmission of glutamate, the most abundant excitatory amino acid neurotransmitter. METHODS We examined our patient population with episodic ataxia and hemiplegic migraine but with no mutation in either CACNA1A or ATP1A2. We looked for mutations in SLC1A3, which encodes the glutamate transporter excitatory amino acid transporter (EAAT) 1 that is important in removing glutamate from the synaptic cleft. RESULTS A patient with episodic ataxia, seizures, migraine, and alternating hemiplegia has a heterozygous mutation in SLC1A3 that is not present in his asymptomatic parents and controls. Expression studies of the mutant EAAT1 showed decreased expression of the protein with a markedly reduced capacity for glutamate uptake. When coexpressed, the mutant EAAT1 decreased the activity of wild-type EAAT1 but not of two other transporters EAAT2 or EAAT3, suggesting that mutant EAAT1 specifically multimerizes with wild-type EAAT1 to exert its dominant negative effect. CONCLUSION Our data show that a heterozygous mutation in EAAT1 can lead to decreased glutamate uptake, which can contribute to neuronal hyperexcitability to cause seizures, hemiplegia, and episodic ataxia.
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Blakely EL, Poulton J, Pike M, Wojnarowska F, Turnbull DM, McFarland R, Taylor RW. Childhood neurological presentation of a novel mitochondrial tRNA(Val) gene mutation. J Neurol Sci 2005; 225:99-103. [PMID: 15465092 DOI: 10.1016/j.jns.2004.07.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2004] [Revised: 06/29/2004] [Accepted: 07/02/2004] [Indexed: 11/26/2022]
Abstract
We describe a young girl with a novel 1659T>C mutation in the tRNA(Val) gene of mitochondrial DNA (mtDNA) who presented with learning difficulties, hemiplegia, and a movement disorder, together with a raised cerebrospinal fluid (CSF) lactate. The mutation, which was present at high levels of heteroplasmy in patient tissues, interrupts a conserved Watson-Crick basepair in the TPsiC stem and has not previously been described in controls. This report further confirms the frequent association of mitochondrial tRNA mutation with neurological presentations, even in paediatric cases.
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Bassi MT, Bresolin N, Tonelli A, Nazos K, Crippa F, Baschirotto C, Zucca C, Bersano A, Dolcetta D, Boneschi FM, Barone V, Casari G. A novel mutation in the ATP1A2 gene causes alternating hemiplegia of childhood. J Med Genet 2004; 41:621-8. [PMID: 15286158 PMCID: PMC1735877 DOI: 10.1136/jmg.2003.017863] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Müllner C, Broos LAM, van den Maagdenberg AMJM, Striessnig J. Familial Hemiplegic Migraine Type 1 Mutations K1336E, W1684R, and V1696I Alter Cav2.1 Ca2+ Channel Gating. J Biol Chem 2004; 279:51844-50. [PMID: 15448138 DOI: 10.1074/jbc.m408756200] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mutations in the Cav2.1 alpha1-subunit of P/Q-type Ca2+ channels cause human diseases, including familial hemiplegic migraine type-1 (FHM1). FHM1 mutations alter channel gating and enhanced channel activity at negative potentials appears to be a common pathogenetic mechanism. Different beta-subunit isoforms (primarily beta4 and beta3) participate in the formation of Cav2.1 channel complexes in mammalian brain. Here we investigated not only whether FHM1 mutations K1336E (KE), W1684R (WR), and V1696I (VI) can affect Cav2.1 channel function but focused on the important question whether mutation-induced changes on channel gating depend on the beta-subunit isoform. Mutants were co-expressed in Xenopus oocytes together with beta1, beta3, or beta4 and alpha2delta1 subunits, and channel function was analyzed using the two-electrode voltage-clamp technique. WR shifted the voltage dependence for steady-state inactivation of Ba2+ inward currents (IBa) to more negative voltages with all beta-subunits tested. In contrast, a similar shift was observed for KE only when expressed with beta3. All mutations promoted IBa decay during pulse trains only when expressed with beta1 or beta3 but not with beta4. Enhanced decay could be explained by delayed recovery from inactivation. KE accelerated IBa inactivation only when co-expressed with beta3, and VI slowed inactivation only with beta1 or beta3. KE and WR shifted channel activation of IBa to more negative voltages. As the beta-subunit composition of Cav2.1 channels varies in different brain regions, our data predict that the functional FHM1 phenotype also varies between different neurons or even within different neuronal compartments.
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Jurkat-Rott K, Freilinger T, Dreier JP, Herzog J, Göbel H, Petzold GC, Montagna P, Gasser T, Lehmann-Horn F, Dichgans M. Variability of familial hemiplegic migraine with novel A1A2 Na+/K+-ATPase variants. Neurology 2004; 62:1857-61. [PMID: 15159495 DOI: 10.1212/01.wnl.0000127310.11526.fd] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
A1A2 Na+/K+-ATPase mutations cause familial hemiplegic migraine type 2 (FHM2). The authors identified three putative A1A2 mutations (D718N, R763H, P979L) and three that await validation (P796R, E902K, X1021R). Ten to 20% of FHM cases may be FHM2. A1A2 mutations have a penetrance of about 87%. D718N causes frequent, long-lasting HM, and P979L may cause recurrent coma. D718N and P979L may predispose to seizures and mental retardation. A1A2 does not play a major role in sporadic HM; only one variant, R383H, occurred in 1 of 24 cases.
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Segall L, Scanzano R, Kaunisto MA, Wessman M, Palotie A, Gargus JJ, Blostein R. Kinetic Alterations due to a Missense Mutation in the Na,K-ATPase α2 Subunit Cause Familial Hemiplegic Migraine Type 2. J Biol Chem 2004; 279:43692-6. [PMID: 15308625 DOI: 10.1074/jbc.m407471200] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A number of missense mutations in the ATP1A2 gene, which encodes the Na,K-ATPase alpha2 subunit, have been identified in familial hemiplegic migraine with aura. Loss of function and haploinsufficiency have been the suggested mechanisms in mutants for which functional analysis has been reported. This paper describes a kinetic analysis of mutant T345A, recently identified in a detailed genetic analysis of a large Finnish family (Kaunisto, M. A., Harno, H., Vanmolkot, K. R., Gargus, J. J., Sun, G., Hamalainen, E., Liukkonen, E., Kallela, M., van den Maagdenberg, A. M., Frants, R. R., Farkkila, M., Palotie, A., and Wessman, M. (2004) Neurogenetics 5, 141-146). Introducing T345A into the conserved rat alpha2 enzyme does not alter cell growth or catalytic turnover but causes a substantial decrease in apparent K+ affinity (2-fold increase in K0.5(K+)). In view of the location of Thr-345 in the cytoplasmic stalk domain adjacent to transmembrane segment 4, the 2-fold increase in K0.5(K+) is probably due to T345A replacement altering K+ occlusion/deocclusion. Faster K+ deocclusion of the mutant via the E2(K) + ATP --> E1.ATP + K+ partial reaction is evidenced in (i) a marked increase (300%) in K+ stimulation of Na-ATPase at micromolar ATP, (ii) a 4-fold decrease in KATP, and (iii) only a modest increase (approximately 3-fold) in I50 for vanadate, which was used as a probe of the steady state E1/E2 conformational equilibrium. We suggest that the decreased apparent K+ affinity is the basis for a reduced rate of extracellular K+ removal, which delays the recovery phase of nerve impulse transmission in the central nervous system and, thereby, the clinical picture of migraine with aura. This is the first demonstration of a mutation that leads to a disease associated with a kinetically altered but fully functional Na,K-ATPase, refining the molecular mechanism of pathogenesis in familial hemiplegic migraine.
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Kors EE, Vanmolkot KRJ, Haan J, Kheradmand Kia S, Stroink H, Laan LAEM, Gill DS, Pascual J, van den Maagdenberg AMJM, Frants RR, Ferrari MD. Alternating hemiplegia of childhood: no mutations in the second familial hemiplegic migraine gene ATP1A2. Neuropediatrics 2004; 35:293-6. [PMID: 15534763 DOI: 10.1055/s-2004-821082] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Alternating hemiplegia of childhood (AHC) is a rare disorder mainly characterised by attacks of hemiplegia and mental retardation. AHC has often been associated with migraine. Previously, we have excluded the involvement of the familial hemiplegic migraine (FHM) CACNA1A gene in four patients with AHC. A second gene for FHM was discovered recently: the ATP1A2 gene on chromosome 1q23, coding for the alpha 2 subunit of Na+,K+-ATPase. We performed a mutation analysis of the ATP1A2 gene in six patients, using direct sequencing, but found no mutations in any of the 23 exons. Other cerebral ion channel genes remain candidate genes for AHC.
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De Deyne PG, Hafer-Macko CE, Ivey FM, Ryan AS, Macko RF. Muscle molecular phenotype after stroke is associated with gait speed. Muscle Nerve 2004; 30:209-15. [PMID: 15266637 DOI: 10.1002/mus.20085] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The disability of patients after stroke is generally attributed to upper motor neuron defects, but secondary changes in paretic muscle may enhance the disability. We analyzed the molecular phenotype and metabolic profile of the paretic and nonparetic vastus lateralis (VL) and we measured the severity of gait deficit in 13 patients at least 6 months after ischemic stroke. The results showed a significant increase in the proportion of fast myosin heavy chain (MHC, 68 +/- 14%) in the paretic compared to the nonparetic VL (50 +/- 13%). The specific activity of citrate synthase and glyceraldehyde phosphodehydrogenase was not significantly different between the two sides. The proportion of fast MHC was inversely associated with severity of gait deficit indexed by self-selected walking speed in the paretic leg, but not the nonparetic leg. Our findings demonstrate significant and potentially modifiable secondary biologic changes in hemiparetic muscle phenotype that may contribute to the disability of stroke.
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