551
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Watrin F, Manent JB, Cardoso C, Represa A. Causes and consequences of gray matter heterotopia. CNS Neurosci Ther 2014; 21:112-22. [PMID: 25180909 DOI: 10.1111/cns.12322] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 07/30/2014] [Accepted: 08/06/2014] [Indexed: 12/17/2022] Open
Abstract
The objective of this article is to review the pathophysiological bases of gray matter heterotopia and to appreciate their involvement in brain cortical development and functional consequences, namely epilepsy. The development of the cerebral cortex results from complex sequential processes including cell proliferation, cell migration, cortical organization, and formation of neuronal networks. Disruption of these steps yields different types of cortical malformations including gray matter heterotopia, characterized by the ectopic position of neurons along the ventricular walls or in the deep white matter. Cortical malformations are major causes of epilepsy, being responsible for up to 40% of drug-resistant epilepsy, and the cognitive level of affected patients varies from normal to severely impaired. This review reports data from human patients and animal models highlighting the genetic causes for these disorders affecting not only neuronal migration but also the proliferation of cortical progenitors. Therefore, gray matter heterotopias should not be considered as solely due to an abnormal neuronal migration and classifying them as such may be too restrictive. The review will also summarize literature data indicating that besides ectopic neurons, neighbor cortical areas also play a consistent role in epileptogenesis, supporting the notion that plastic changes secondary to the initial malformation are instrumental in the pathophysiology of epilepsy in affected patients.
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Affiliation(s)
- Françoise Watrin
- INSERM, INMED, Marseille, France; Aix-Marseille University, UMR 901, Marseille, France
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552
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Bardón-Cancho EJ, Muñoz-Jiménez L, Vázquez-López M, Ruíz-Martín Y, García-Morín M, Barredo-Valderrama E. Periventricular nodular heterotopia and dystonia due to an ARFGEF2 mutation. Pediatr Neurol 2014; 51:461-4. [PMID: 25160555 DOI: 10.1016/j.pediatrneurol.2014.05.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 05/11/2014] [Accepted: 05/12/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND Heterotopias are a neuronal migration disorder caused by extrinsic factors or by genetic mutations. When the location is periventricular, the most frequent genetic cause is the mutation in the "filamin A2 gene", which is X-linked. New genes for periventricular nodular heterotopia with an autosomal inheritance pattern have been recently discovered. PATIENTS We describe two siblings. The girl, who was prenatally diagnosed ventriculomegaly, had delayed development. At 6 months, she had no head control and variable muscle tone, alternating low axial tone with jerking movements. She became microcephalic. Magnetic resonance imaging at 12 months of age revealed enlarged lateral ventricles, periventricular nodular heterotopia, thin corpus callosum, a T2-hyperintensity of the putamen and the thalamus, and a loss of volume of lenticular nucleus. At 18 months, she developed sporadic myoclonic seizures that were well controlled with valproic acid. Her younger brother also developed progressive microcephaly and psychomotor delay by 6 months. He exhibited axial hypotonia with a prominent dystonic-athetoid component. Magnetic resonance imaging at 15 months of age revealed asymmetric ventriculomegaly plus diffuse nodules lining the temporal horns, a thin corpus callosum, and hyperintensity signal in putamens. He had no seizures. RESULTS Because of the association of microcephaly, developmental delay with dystonic movements, the imaging results, and the probable autosomal recessive inheritance pattern, genetic analysis was requested. This detected a homozygous nonsense mutation in ARFGEF2 gene, at the DNA level c.388C>T in exon 4. CONCLUSIONS The presence of dyskinetic movements in individuals with acquired microcephaly could be a manifestation of periventricular nodular heterotopia due to ARFGEF2 mutation.
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Affiliation(s)
| | - Lucía Muñoz-Jiménez
- Department of Pediatrics, Hospital General Universitario Gregorio Marañón, Madrid, Spain
| | - María Vázquez-López
- Department of Pediatrics, Hospital General Universitario Gregorio Marañón, Madrid, Spain; Section of Neuropediatrics, Department of Pediatrics, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
| | - Yolanda Ruíz-Martín
- Section of Pediatric Radiology, Department of Radiology, Hospital General Universitario Gregorio Marañón, Madrid, Spain
| | - Marina García-Morín
- Department of Pediatrics, Hospital General Universitario Gregorio Marañón, Madrid, Spain
| | - Estíbaliz Barredo-Valderrama
- Department of Pediatrics, Hospital General Universitario Gregorio Marañón, Madrid, Spain; Section of Neuropediatrics, Department of Pediatrics, Hospital General Universitario Gregorio Marañón, Madrid, Spain
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553
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Barak B, Feldman N, Okun E. Toll-like receptors as developmental tools that regulate neurogenesis during development: an update. Front Neurosci 2014; 8:272. [PMID: 25221470 PMCID: PMC4148028 DOI: 10.3389/fnins.2014.00272] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 08/11/2014] [Indexed: 12/18/2022] Open
Abstract
Neurogenesis, the process of generating new neurons in the brain, fascinates researchers for its promise to affect multiple cognitive and functional processes in both health and disease. Many cellular pathways are involved in the regulation of neurogenesis, a complexity exemplified by the extensive regulation of this process during brain development. Toll-like receptors (TLRs), hallmarks of innate immunity, are increasingly implemented in various central nervous system plasticity-related processes including neurogenesis. As TLRs are involved in neurodegenerative disorders, understanding the involvement of TLRs in neurogenesis may hold keys for future therapeutic interventions. Herein, we describe the current knowledge on the involvement of TLRs in neurogenesis and neuronal plasticity and point to current knowledge gaps in the field.
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Affiliation(s)
- Boaz Barak
- McGovern Institute for Brain Research and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology Cambridge, MA, USA
| | - Noa Feldman
- The Mina and Everard Goodman Faculty of Life Sciences, The Gonda Multidisciplinary Brain Research Center, Bar Ilan University Ramat-Gan, Israel
| | - Eitan Okun
- The Mina and Everard Goodman Faculty of Life Sciences, The Gonda Multidisciplinary Brain Research Center, Bar Ilan University Ramat-Gan, Israel
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554
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Sahai I, Mochida GH, Grabowski EF, Caruso PA. Case records of the Massachusetts General Hospital. Case 27-2014. A 10-month-old boy with microcephaly and episodic cyanosis. N Engl J Med 2014; 371:847-58. [PMID: 25162892 DOI: 10.1056/nejmcpc1400833] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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555
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Bahi-Buisson N, Poirier K, Fourniol F, Saillour Y, Valence S, Lebrun N, Hully M, Bianco CF, Boddaert N, Elie C, Lascelles K, Souville I, Beldjord C, Chelly J. The wide spectrum of tubulinopathies: what are the key features for the diagnosis? ACTA ACUST UNITED AC 2014; 137:1676-700. [PMID: 24860126 DOI: 10.1093/brain/awu082] [Citation(s) in RCA: 206] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Complex cortical malformations associated with mutations in tubulin genes: TUBA1A, TUBA8, TUBB2B, TUBB3, TUBB5 and TUBG1 commonly referred to as tubulinopathies, are a heterogeneous group of conditions with a wide spectrum of clinical severity. Among the 106 patients selected as having complex cortical malformations, 45 were found to carry mutations in TUBA1A (42.5%), 18 in TUBB2B (16.9%), 11 in TUBB3 (10.4%), three in TUBB5 (2.8%), and three in TUBG1 (2.8%). No mutations were identified in TUBA8. Systematic review of patients' neuroimaging and neuropathological data allowed us to distinguish at least five cortical malformation syndromes: (i) microlissencephaly (n = 12); (ii) lissencephaly (n = 19); (iii) central pachygyria and polymicrogyria-like cortical dysplasia (n = 24); (iv) generalized polymicrogyria-like cortical dysplasia (n = 6); and (v) a 'simplified' gyral pattern with area of focal polymicrogyria (n = 19). Dysmorphic basal ganglia are the hallmark of tubulinopathies (found in 75% of cases) and are present in 100% of central pachygyria and polymicrogyria-like cortical dysplasia and simplified gyral malformation syndromes. Tubulinopathies are also characterized by a high prevalence of corpus callosum agenesis (32/80; 40%), and mild to severe cerebellar hypoplasia and dysplasia (63/80; 78.7%). Foetal cases (n = 25) represent the severe end of the spectrum and show specific abnormalities that provide insights into the underlying pathophysiology. The overall complexity of tubulinopathies reflects the pleiotropic effects of tubulins and their specific spatio-temporal profiles of expression. In line with previous reports, this large cohort further clarifies overlapping phenotypes between tubulinopathies and although current structural data do not allow prediction of mutation-related phenotypes, within each mutated gene there is an associated predominant pattern of cortical dysgenesis allowing some phenotype-genotype correlation. The core phenotype of TUBA1A and TUBG1 tubulinopathies are lissencephalies and microlissencephalies, whereas TUBB2B tubulinopathies show in the majority, centrally predominant polymicrogyria-like cortical dysplasia. By contrast, TUBB3 and TUBB5 mutations cause milder malformations with focal or multifocal polymicrogyria-like cortical dysplasia with abnormal and simplified gyral pattern.
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Affiliation(s)
- Nadia Bahi-Buisson
- 1 Institut Cochin, Université Paris-Descartes, CNRS (UMR 8104), Paris, France2 Inserm, U1016, Paris, France3 Université Paris Descartes, Sorbonne Paris Cité, Institut Imagine, Paris, France4 INSERM UMR-1163, Embryology and genetics of congenital malformations, Paris, France5 Service de Neurologie pédiatrique, Assistance Publique-Hôpitaux de Paris (AP-HP), hôpital Necker, Paris, France
| | - Karine Poirier
- 1 Institut Cochin, Université Paris-Descartes, CNRS (UMR 8104), Paris, France2 Inserm, U1016, Paris, France
| | | | - Yoann Saillour
- 1 Institut Cochin, Université Paris-Descartes, CNRS (UMR 8104), Paris, France2 Inserm, U1016, Paris, France
| | - Stéphanie Valence
- 1 Institut Cochin, Université Paris-Descartes, CNRS (UMR 8104), Paris, France2 Inserm, U1016, Paris, France
| | - Nicolas Lebrun
- 1 Institut Cochin, Université Paris-Descartes, CNRS (UMR 8104), Paris, France2 Inserm, U1016, Paris, France
| | - Marie Hully
- 5 Service de Neurologie pédiatrique, Assistance Publique-Hôpitaux de Paris (AP-HP), hôpital Necker, Paris, France
| | | | - Nathalie Boddaert
- 8 Service de Radiologie Pédiatrique, AP-HP, hôpital Necker, Paris, France9 Inserm, U797-INSERM-CEA, Service Hospitalier Frédéric Joliot, CEA, 4, place du General Leclerc, 91406, Orsay, France
| | - Caroline Elie
- 10 BioInformatic Department-AP-HP, hôpital Necker-Enfants Malades, Paris, France
| | | | - Isabelle Souville
- 12 Service de Biologie Moleculaire et Genetique, Pavillon Cassini AP-HP, Hôpital Cochin, Paris, France
| | | | - Cherif Beldjord
- 12 Service de Biologie Moleculaire et Genetique, Pavillon Cassini AP-HP, Hôpital Cochin, Paris, France
| | - Jamel Chelly
- 1 Institut Cochin, Université Paris-Descartes, CNRS (UMR 8104), Paris, France2 Inserm, U1016, Paris, France
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556
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Schmid MT, Weinandy F, Wilsch-Bräuninger M, Huttner WB, Cappello S, Götz M. The role of α-E-catenin in cerebral cortex development: radial glia specific effect on neuronal migration. Front Cell Neurosci 2014; 8:215. [PMID: 25147501 PMCID: PMC4124588 DOI: 10.3389/fncel.2014.00215] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 07/16/2014] [Indexed: 12/02/2022] Open
Abstract
During brain development, radial glial cells possess an apico-basal polarity and are coupled by adherens junctions (AJs) to an F-actin belt. To elucidate the role of the actin, we conditionally deleted the key component α-E-catenin in the developing cerebral cortex. Deletion at early stages resulted in severe disruption of tissue polarity due to uncoupling of AJs with the intracellular actin fibers leading to the formation of subcortical band heterotopia. Interestingly, this phenotype closely resembled the phenotype obtained by conditional RhoA deletion, both in regard to the macroscopic subcortical band heterotopia and the subcellular increase in G-actin/F-actin ratio. These data therefore together corroborate the role of the actin cytoskeleton and its anchoring to the AJs for neuronal migration disorders.
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Affiliation(s)
- Marie-Theres Schmid
- Helmholtz Zentrum München, National Research Center for Environmental Health, Institute of Stem Cell Research Neuherberg/Munich, Germany
| | - Franziska Weinandy
- Helmholtz Zentrum München, National Research Center for Environmental Health, Institute of Stem Cell Research Neuherberg/Munich, Germany
| | | | - Wieland B Huttner
- Max Planck Institute of Molecular Cell Biology and Genetics Dresden, Germany
| | - Silvia Cappello
- Helmholtz Zentrum München, National Research Center for Environmental Health, Institute of Stem Cell Research Neuherberg/Munich, Germany ; Department of Physiological Genomics, Institute of Physiology, University of Munich Munich, Germany
| | - Magdalena Götz
- Helmholtz Zentrum München, National Research Center for Environmental Health, Institute of Stem Cell Research Neuherberg/Munich, Germany ; Department of Physiological Genomics, Institute of Physiology, University of Munich Munich, Germany
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557
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Simplified gyral pattern in severe developmental microcephalies? New insights from allometric modeling for spatial and spectral analysis of gyrification. Neuroimage 2014; 102 Pt 2:317-31. [PMID: 25107856 DOI: 10.1016/j.neuroimage.2014.07.057] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 07/28/2014] [Accepted: 07/28/2014] [Indexed: 01/13/2023] Open
Abstract
The strong positive-allometric relationship between brain size, cortical extension and gyrification complexity, recently highlighted in the general population, could be modified by brain developmental disorders. Indeed, in case of brain growth insufficiency, the pathophysiological relevance of the "simplified gyral pattern" phenotype is strongly disputed since almost no genotype-phenotype correlations have been found in primary microcephalies. Using surface scaling analysis and newly-developed spectral analysis of gyrification (Spangy), we tested whether the gyral simplification in groups of severe microcephalies related to ASPM, PQBP1 or fetal-alcohol-syndrome could be fully explained by brain size reduction according to the allometric scaling law established in typically-developing control groups, or whether an additional disease effect was to be suspected. We found the surface area reductions to be fully explained by scaling effect, leading to predictable folding intensities measured by gyrification indices. As for folding pattern assessed by spectral analysis, scaling effect also accounted for the majority of the variations, but an additional negative or positive disease effect was found in the case of ASPM and PQBP1-linked microcephalies, respectively. Our results point out the necessity of taking allometric scaling into account when studying the gyrification variability in pathological conditions. They also show that the quantitative analysis of gyrification complexity through spectral analysis can enable distinguishing between even (predictable, non-specific) and uneven (unpredictable, maybe disease-specific) gyral simplifications.
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558
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Jain P, Dhingra D, Kumar A, Sharma S, Chandra J, Aneja S. Lissencephaly with subcortical band heterotopia in an Indian family. Indian J Pediatr 2014; 81:844-5. [PMID: 24493317 DOI: 10.1007/s12098-013-1333-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 12/27/2013] [Indexed: 11/29/2022]
Affiliation(s)
- Puneet Jain
- Pediatric Neurology, Department of Pediatrics, Lady Hardinge Medical College and Associated Kalawati Saran Children's Hospital, New Delhi, 110001, India,
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559
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Fallet-Bianco C, Laquerrière A, Poirier K, Razavi F, Guimiot F, Dias P, Loeuillet L, Lascelles K, Beldjord C, Carion N, Toussaint A, Revencu N, Addor MC, Lhermitte B, Gonzales M, Martinovich J, Bessieres B, Marcy-Bonnière M, Jossic F, Marcorelles P, Loget P, Chelly J, Bahi-Buisson N. Mutations in tubulin genes are frequent causes of various foetal malformations of cortical development including microlissencephaly. Acta Neuropathol Commun 2014; 2:69. [PMID: 25059107 PMCID: PMC4222268 DOI: 10.1186/2051-5960-2-69] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 06/04/2014] [Indexed: 01/18/2023] Open
Abstract
Complex cortical malformations associated with mutations in tubulin genes are commonly referred to as “Tubulinopathies”. To further characterize the mutation frequency and phenotypes associated with tubulin mutations, we studied a cohort of 60 foetal cases. Twenty-six tubulin mutations were identified, of which TUBA1A mutations were the most prevalent (19 cases), followed by TUBB2B (6 cases) and TUBB3 (one case). Three subtypes clearly emerged. The most frequent (n = 13) was microlissencephaly with corpus callosum agenesis, severely hypoplastic brainstem and cerebellum. The cortical plate was either absent (6/13), with a 2–3 layered pattern (5/13) or less frequently thickened (2/13), often associated with neuroglial overmigration (4/13). All cases had voluminous germinal zones and ganglionic eminences. The second subtype was lissencephaly (n = 7), either classical (4/7) or associated with cerebellar hypoplasia (3/7) with corpus callosum agenesis (6/7). All foetuses with lissencephaly and cerebellar hypoplasia carried distinct TUBA1A mutations, while those with classical lissencephaly harbored recurrent mutations in TUBA1A (3 cases) or TUBB2B (1 case). The third group was polymicrogyria-like cortical dysplasia (n = 6), consisting of asymmetric multifocal or generalized polymicrogyria with inconstant corpus callosum agenesis (4/6) and hypoplastic brainstem and cerebellum (3/6). Polymicrogyria was either unlayered or 4-layered with neuronal heterotopias (5/6) and occasional focal neuroglial overmigration (2/6). Three had TUBA1A mutations and 3 TUBB2B mutations. Foetal TUBA1A tubulinopathies most often consist in microlissencephaly or classical lissencephaly with corpus callosum agenesis, but polymicrogyria may also occur. Conversely, TUBB2B mutations are responsible for either polymicrogyria (4/6) or microlissencephaly (2/6).
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560
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Shimojima K, Narita A, Maegaki Y, Saito A, Furukawa T, Yamamoto T. Whole-exome sequencing identifies a de novo TUBA1A mutation in a patient with sporadic malformations of cortical development: a case report. BMC Res Notes 2014; 7:465. [PMID: 25053001 PMCID: PMC4118784 DOI: 10.1186/1756-0500-7-465] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 07/14/2014] [Indexed: 12/20/2022] Open
Abstract
Background Owing to the number of genetic mutations that contribute to malformations of cortical development, identification of causative mutations in candidate genes is challenging. To overcome these challenges, we performed whole-exome sequencing in this study. Case presentation A Japanese patient presented with microcephaly and severe developmental delay. Brain magnetic resonance imaging showed the presence of colpocephaly associated with lateral ventricle dilatation and the presence of a simplified gyral pattern. Hypoplasia of the corpus callosum and cerebellar vermis were also noted. Because Sanger sequencing is expensive, laborious, and time-consuming, whole-exome sequencing was performed and a de novo missense mutation in TUBA1A (E27Q) was identified. Conclusion The novel mutation identified in this study was located in the genetic region that encodes the N-terminal domain of TUBA1A, a region of TUBA1A with few reported mutations. Retrospective assessment of the clinical and radiological features of this patient―i.e., microcephaly, lissencephaly (pachygyria) with cerebellar hypoplasia, and corpus callosum hypoplasia―indicated that the TUBA1A mutation did not lead to any contradictions. Because rapid and comprehensive mutation analysis by whole-exome sequencing is time- and cost-effective, it might be useful for genetic counseling of patients with sporadic malformations of cortical development.
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Affiliation(s)
| | | | | | | | | | - Toshiyuki Yamamoto
- Tokyo Women's Medical University Institute for Integrated Medical Sciences, Tokyo 162-8666, Japan.
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561
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Najm IM, Tassi L, Sarnat HB, Holthausen H, Russo GL. Epilepsies associated with focal cortical dysplasias (FCDs). Acta Neuropathol 2014; 128:5-19. [PMID: 24916270 DOI: 10.1007/s00401-014-1304-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Revised: 05/26/2014] [Accepted: 05/26/2014] [Indexed: 11/24/2022]
Abstract
Focal cortical dysplasias (FCDs) are increasingly recognized as one of the most common causes of pharmaco-resistant epilepsies. FCDs were recently divided into various clinico-pathological subtypes due to distinct imaging, electrophysiological, and outcome characteristics. In this review, we will overview the international consensus classification of FCDs in light of more recently reported clinical, electrical, imaging and functional observations, and will also address areas of ongoing debate. In addition, we will summarize our current knowledge on pathobiology and epileptogenicity of FCDs as well as its underlying molecular and cellular mechanisms. The clinical (electroencephalographic, imaging, and functional) characteristics of major FCD subtypes and their implications on the presurgical evaluation and surgical management will be discussed in light of studies describing these characteristics and postoperative seizure outcomes in patients with medically intractable focal epilepsy due to histopathologically confirmed FCDs.
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Affiliation(s)
- Imad M Najm
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA,
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562
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Marin-Valencia I, Guerrini R, Gleeson JG. Pathogenetic mechanisms of focal cortical dysplasia. Epilepsia 2014; 55:970-8. [PMID: 24861491 PMCID: PMC4107035 DOI: 10.1111/epi.12650] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/04/2014] [Indexed: 02/01/2023]
Abstract
Focal cortical dysplasias (FCDs) constitute a prevalent cause of intractable epilepsy in children, and is one of the leading conditions requiring epilepsy surgery. Despite recent advances in the cellular and molecular biology of these conditions, the pathogenetic mechanisms of FCDs remain largely unknown. The purpose if this work is to review the molecular underpinnings of FCDs and to highlight potential therapeutic targets. A systematic review of the literature regarding the histologic, molecular, and electrophysiologic aspects of FCDs was conducted. Disruption of the mammalian target of rapamycin (mTOR) signaling comprises a common pathway underlying the structural and electrical disturbances of some FCDs. Other mechanisms such as viral infections, prematurity, head trauma, and brain tumors are also posited. mTOR inhibitors (i.e., rapamycin) have shown positive results on seizure management in animal models and in a small cohort of patients with FCD. Encouraging progress has been achieved on the molecular and electrophysiologic basis of constitutive cells in the dysplastic tissue. Despite the promising results of mTOR inhibitors, large-scale randomized trials are in need to evaluate their efficacy and side effects, along with additional mechanistic studies for the development of novel, molecular-based diagnostic and therapeutic approaches.
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Affiliation(s)
- Isaac Marin-Valencia
- Department of Neurology and Neurotherapeutics, and Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, U.S.A
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563
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Abstract
The term hemispherectomy refers to the complete removal or functional disconnection of a cerebral hemisphere. The technique was initially developed over 85 years ago to treat infiltrating brain tumors but is now used exclusively for medically refractory epilepsy. Hemispherectomy surgery has progressed from an extremely morbid procedure fraught with complications to a fairly routine one performed at most pediatric epilepsy centers with relatively low risk and great efficacy. The author reviews the history and evolution of hemispherectomy surgery, the relevant pathological conditions, as well as outcomes and complications.
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Affiliation(s)
- Sean M Lew
- Medical College of Wisconsin, Children's Hospital of Wisconsin, Milwaukee, WI 53226, USA
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564
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Wilke M, Rose DF, Holland SK, Leach JL. Multidimensional morphometric 3D MRI analyses for detecting brain abnormalities in children: impact of control population. Hum Brain Mapp 2014; 35:3199-215. [PMID: 25050423 PMCID: PMC6869842 DOI: 10.1002/hbm.22395] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 07/24/2013] [Accepted: 08/02/2013] [Indexed: 11/07/2022] Open
Abstract
Automated morphometric approaches are used to detect epileptogenic structural abnormalities in 3D MR images in adults, using the variance of a control population to obtain z-score maps in an individual patient. Due to the substantial changes the developing human brain undergoes, performing such analyses in children is challenging. This study investigated six features derived from high-resolution T1 datasets in four groups: normal children (1.5T or 3T data), normal clinical scans (3T data), and patients with structural brain lesions (3T data), with each n = 10. Normative control data were obtained from the NIH study on normal brain development (n = 401). We show that control group size substantially influences the captured variance, directly impacting the patient's z-scores. Interestingly, matching on gender does not seem to be beneficial, which was unexpected. Using data obtained at higher field scanners produces slightly different base rates of suprathreshold voxels, as does using clinically derived normal studies, suggesting a subtle but systematic effect of both factors. Two approaches for controlling suprathreshold voxels in a multidimensional approach (combining features and requiring a minimum cluster size) were shown to be substantial and effective in reducing this number. Finally, specific strengths and limitations of such an approach could be demonstrated in individual cases.
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Affiliation(s)
- Marko Wilke
- Department of Pediatric Neurology and Developmental MedicineChildren's Hospital, University of TübingenGermany
- Experimental Pediatric Neuroimaging, Children's Hospital and Department of NeuroradiologyUniversity of TübingenGermany
- Department of NeurologyCincinnati Children's Hospital Medical CenterCincinnatiOhio
- Department of RadiologyCincinnati Children's Hospital Medical CenterCincinnatiOhio
| | - Douglas F. Rose
- Department of NeurologyCincinnati Children's Hospital Medical CenterCincinnatiOhio
| | - Scott K. Holland
- Pediatric Neuroimaging Research ConsortiumCincinnati Children's Hospital Medical CenterCincinnatiOhio
| | - James L. Leach
- Department of RadiologyCincinnati Children's Hospital Medical CenterCincinnatiOhio
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565
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Kamiya K, Sato N, Saito Y, Nakata Y, Ito K, Shigemoto Y, Ota M, Sasaki M, Ohtomo K. Accelerated myelination along fiber tracts in patients with hemimegalencephaly. J Neuroradiol 2014; 41:202-10. [DOI: 10.1016/j.neurad.2013.08.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 08/26/2013] [Accepted: 08/29/2013] [Indexed: 10/26/2022]
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566
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Ma L, Li XW, Zhang SJ, Yang F, Zhu GM, Yuan XB, Jiang W. Interleukin-1 beta guides the migration of cortical neurons. J Neuroinflammation 2014; 11:114. [PMID: 24950657 PMCID: PMC4084576 DOI: 10.1186/1742-2094-11-114] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 06/05/2014] [Indexed: 11/20/2022] Open
Abstract
Background Proinflammatory cytokine interleukin-1beta (IL-1β) is expressed at high levels in the developing brain and declines to low constitutive levels in the adult. However, the pathophysiological function of IL-1β during brain development remains elusive. In this study, we investigated the role of IL-1β in neuronal migration. Methods The Boyden transwell assay was used to examine the effects of IL-1β on the migration of dissociated primary cortical neurons. To determine the role of IL-1β in neuron leading process pathfinding, we employed a growth cone turning assay. In utero electroporation combined with RNAi technology was used to examine the neuronal migration in vivo during brain development in Sprague–Dawley rats. Results IL-1β at concentrations ranging from 0.1 to 10 ng/mL in the lower chamber of a transwell induced a significant increase in the number of migrating neurons in a dose-dependent manner. When IL-1β was simultaneously put in both the upper and lower chambers to eliminate the gradient, no significant differences in cell migration were observed. IL-1 receptor antagonist IL-1RA dose-dependently blocked the attractive effect of IL-1β on neuronal migration. Microscopic gradients of IL-1β were created near the growth cones of isolated neurons by repetitive pulsatile application of picoliters of a IL-1β-containing solution with a micropipette. We found that growth cones exhibited a clear bias toward the source of IL-1β at the end of a one hour period in the IL-1β gradient. No significant difference was observed in the rate of neurite extension between IL-1β and controls. We electroporated specific siRNA constructs against IL-1R1 mRNA into cortical progenitors at embryonic day 16 and examined the position and distribution of transfected cells in the somatosensory cortex at postnatal day 5. We found that neurons transfected with IL-1R1-siRNA displayed a severe retardation in radial migration, with about 83% of total cells unable to arrive at the upper cortical layers. Conclusions Our study suggests an essential contribution of IL-1β to neuronal migration during brain development, which provides a basis to understand the physiological roles of IL-1β in the developing brain and could have significant implications for the prevention of some neurodevelopment disorders due to abnormal neuronal migration.
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Affiliation(s)
| | | | | | | | | | | | - Wen Jiang
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China.
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567
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Barba C, Parrini E, Coras R, Galuppi A, Craiu D, Kluger G, Parmeggiani A, Pieper T, Schmitt-Mechelke T, Striano P, Giordano F, Blumcke I, Guerrini R. Co-occurring malformations of cortical development and SCN1A gene mutations. Epilepsia 2014; 55:1009-19. [PMID: 24902755 DOI: 10.1111/epi.12658] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/14/2014] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To report on six patients with SCN1A mutations and malformations of cortical development (MCDs) and describe their clinical course, genetic findings, and electrographic, imaging, and neuropathologic features. METHODS Through our database of epileptic encephalopathies, we identified 120 patients with SCN1A mutations, of which 4 had magnetic resonance imaging (MRI) evidence of MCDs. We collected two further similar observations through the European Task-force for Epilepsy Surgery in Children. RESULTS The study group consisted of five males and one female (mean age 7.4 ± 5.3 years). All patients exhibited electroclinical features consistent with the Dravet syndrome spectrum, cognitive impairment, and autistic features. Sequencing analysis of the SCN1A gene detected two missense, two truncating, and two splice-site mutations. Brain MRI revealed bilateral periventricular nodular heterotopia (PNH) in two patients and focal cortical dysplasia (FCD) in three, and disclosed no macroscopic abnormality in one. In the MRI-negative patient, neuropathologic study of the whole brain performed after sudden unexpected death in epilepsy (SUDEP), revealed multifocal micronodular dysplasia in the left temporal lobe. Two patients with FCD underwent epilepsy surgery. Neuropathology revealed FCD type IA and type IIA. Their seizure outcome was unfavorable. All four patients with FCD exhibited multiple seizure types, which always included complex partial seizures, the area of onset of which co-localized with the region of structural abnormality. SIGNIFICANCE MCDs and SCN1A gene mutations can co-occur. Although epidemiology does not support a causative role for SCN1A mutations, loss or impaired protein function combined with the effect of susceptibility factors and genetic modifiers of the phenotypic expression of SCN1A mutations might play a role. MCDs, particularly FCD, can influence the electroclinical phenotype in patients with SCN1A-related epilepsy. In patients with MCDs and a history of polymorphic seizures precipitated by fever, SCN1A gene testing should be performed before discussing any epilepsy surgery option, due to the possible implications for outcome.
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Affiliation(s)
- Carmen Barba
- Pediatric Neurology Unit and Laboratories, Children's Hospital Meyer-University of Florence, Florence, Italy
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568
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Hong SJ, Kim H, Schrader D, Bernasconi N, Bernhardt BC, Bernasconi A. Automated detection of cortical dysplasia type II in MRI-negative epilepsy. Neurology 2014; 83:48-55. [PMID: 24898923 DOI: 10.1212/wnl.0000000000000543] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
OBJECTIVE To detect automatically focal cortical dysplasia (FCD) type II in patients with extratemporal epilepsy initially diagnosed as MRI-negative on routine inspection of 1.5 and 3.0T scans. METHODS We implemented an automated classifier relying on surface-based features of FCD morphology and intensity, taking advantage of their covariance. The method was tested on 19 patients (15 with histologically confirmed FCD) scanned at 3.0T, and cross-validated using a leave-one-out strategy. We assessed specificity in 24 healthy controls and 11 disease controls with temporal lobe epilepsy. Cross-dataset classification performance was evaluated in 20 healthy controls and 14 patients with histologically verified FCD examined at 1.5T. RESULTS Sensitivity was 74%, with 100% specificity (i.e., no lesions detected in healthy or disease controls). In 50% of cases, a single cluster colocalized with the FCD lesion, while in the remaining cases a median of 1 extralesional cluster was found. Applying the classifier (trained on 3.0T data) to the 1.5T dataset yielded comparable performance (sensitivity 71%, specificity 95%). CONCLUSION In patients initially diagnosed as MRI-negative, our fully automated multivariate approach offered a substantial gain in sensitivity over standard radiologic assessment. The proposed method showed generalizability across cohorts, scanners, and field strengths. Machine learning may assist presurgical decision-making by facilitating hypothesis formulation about the epileptogenic zone. CLASSIFICATION OF EVIDENCE This study provides Class II evidence that automated machine learning of MRI patterns accurately identifies FCD among patients with extratemporal epilepsy initially diagnosed as MRI-negative.
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Affiliation(s)
- Seok-Jun Hong
- From the NeuroImaging of Epilepsy Laboratory, Department of Neurology and McConnell Brain Imaging Center, McGill University, Montreal Neurological Institute and Hospital, Canada
| | - Hosung Kim
- From the NeuroImaging of Epilepsy Laboratory, Department of Neurology and McConnell Brain Imaging Center, McGill University, Montreal Neurological Institute and Hospital, Canada
| | - Dewi Schrader
- From the NeuroImaging of Epilepsy Laboratory, Department of Neurology and McConnell Brain Imaging Center, McGill University, Montreal Neurological Institute and Hospital, Canada
| | - Neda Bernasconi
- From the NeuroImaging of Epilepsy Laboratory, Department of Neurology and McConnell Brain Imaging Center, McGill University, Montreal Neurological Institute and Hospital, Canada
| | - Boris C Bernhardt
- From the NeuroImaging of Epilepsy Laboratory, Department of Neurology and McConnell Brain Imaging Center, McGill University, Montreal Neurological Institute and Hospital, Canada
| | - Andrea Bernasconi
- From the NeuroImaging of Epilepsy Laboratory, Department of Neurology and McConnell Brain Imaging Center, McGill University, Montreal Neurological Institute and Hospital, Canada.
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Kumar VS, Sangeeta VB, Shubrata KS, Nagaraja AV. A novel case of 'muscle eye brain disease' in an immigrant family in India. J Pediatr Neurosci 2014; 9:88-9. [PMID: 24891919 PMCID: PMC4040049 DOI: 10.4103/1817-1745.131501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- Vikram S Kumar
- Department of Pediatrics, Division of Child Psychiatry, Subbaiah Institute of Medical Sciences and Research Centre, Purlae, Shimoga, India
| | - V B Sangeeta
- Department of Pediatrics, Raja Rajeshwari Medical College, Bangalore, Karnataka, India
| | - K S Shubrata
- Department of Psychiatry, Division of Child Psychiatry, Subbaiah Institute of Medical Sciences and Research Centre, Purlae, Shimoga, India
| | - A V Nagaraja
- Consultant Neurologist, Nagaraja Neuroclinic, Shimoga, India
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Abstract
Malformations of cortical development are common causes of developmental delay and epilepsy. Some patients have early, severe neurological impairment, but others have epilepsy or unexpected deficits that are detectable only by screening. The rapid evolution of molecular biology, genetics, and imaging has resulted in a substantial increase in knowledge about the development of the cerebral cortex and the number and types of malformations reported. Genetic studies have identified several genes that might disrupt each of the main stages of cell proliferation and specification, neuronal migration, and late cortical organisation. Many of these malformations are caused by de-novo dominant or X-linked mutations occurring in sporadic cases. Genetic testing needs accurate assessment of imaging features, and familial distribution, if any, and can be straightforward in some disorders but requires a complex diagnostic algorithm in others. Because of substantial genotypic and phenotypic heterogeneity for most of these genes, a comprehensive analysis of clinical, imaging, and genetic data is needed to properly define these disorders. Exome sequencing and high-field MRI are rapidly modifying the classification of these disorders.
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Affiliation(s)
- Renzo Guerrini
- Department of Neuroscience, Pharmacology and Child Health, Children's Hospital A Meyer and University of Florence, Florence, Italy; Stella Maris Foundation Research Institute, Pisa, Italy.
| | - William B Dobyns
- Departments of Pediatrics and Neurology, University of Washington, Seattle, WA, USA; Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, USA
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Stutterd CA, Leventer RJ. Polymicrogyria: a common and heterogeneous malformation of cortical development. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2014; 166C:227-39. [PMID: 24888723 DOI: 10.1002/ajmg.c.31399] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Polymicrogyria (PMG) is one of the most common malformations of cortical development. It is characterized by overfolding of the cerebral cortex and abnormal cortical layering. It is a highly heterogeneous malformation with variable clinical and imaging features, pathological findings, and etiologies. It may occur as an isolated cortical malformation, or in association with other malformations within the brain or body as part of a multiple congenital anomaly syndrome. Polymicrogyria shows variable topographic patterns with the bilateral perisylvian pattern being most common. Schizencephaly is a subtype of PMG in which the overfolded cortex lines full-thickness clefts connecting the subarachnoid space with the cerebral ventricles. Both genetic and non-genetic causes of PMG have been identified. Non-genetic causes include congenital cytomegalovirus infection and in utero ischemia. Genetic causes include metabolic conditions such as peroxisomal disorders and the 22q11.2 and 1p36 continguous gene deletion syndromes. Mutations in over 30 genes have been found in association with PMG, especially mutations in the tubulin family of genes. Mutations in the (PI3K)-AKT pathway have been found in association PMG and megalencephaly. Despite recent genetic advances, the mechanisms by which polymicrogyric cortex forms and causes of the majority of cases remain unknown, making diagnostic and prenatal testing and genetic counseling challenging. This review summarizes the clinical, imaging, pathologic, and etiologic features of PMG, highlighting recent genetic advances.
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572
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Mutations in Eml1 lead to ectopic progenitors and neuronal heterotopia in mouse and human. Nat Neurosci 2014; 17:923-33. [DOI: 10.1038/nn.3729] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 04/29/2014] [Indexed: 12/17/2022]
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573
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Fry AE, Cushion TD, Pilz DT. The genetics of lissencephaly. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2014; 166C:198-210. [DOI: 10.1002/ajmg.c.31402] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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574
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Mirzaa GM, Paciorkowski AR. Introduction: Brain malformations. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2014; 166C:117-23. [PMID: 24853778 DOI: 10.1002/ajmg.c.31404] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This issue of the American Journal of Medical Genetics Seminar Series Part C is dedicated to congenital brain malformations with a special focus on the molecular mechanisms underlying this fascinating, and often complex, group of developmental brain disorders. As with most genetic disorders, the past few years have witnessed a dramatic leap in our understanding of the molecular basis of these malformations that include both constitutional and post-zygotic (or mosaic) genetic aberrations. This is best exemplified by the recent identification of mutations within components of the PI3K-AKT-mTOR pathway in hemimegalencephaly and megalencephaly syndromes, and the rapidly increased identification of mutations within the tubulin family in a broad range of cortical and non-cortical brain malformations. These discoveries, particularly of the emerging "tubulinopathies" spectrum, have not only expanded our knowledge of these disorders but challenge our existing, and perhaps overly simplistic, classification of these malformations based on the primary neuronal stage at which the abnormality occurs. It is our hope that this series will facilitate a deeper understanding of these malformations beyond their clinical and neuroimaging features and syndromic associations to their molecular and pathway underpinnings. We believe this knowledge will most certainly be instrumental as we move into the era of delineating genotype-phenotype correlations and, ultimately, pathway-based therapies.
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575
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Poulton CJ, Schot R, Seufert K, Lequin MH, Accogli A, Annunzio GD, Villard L, Philip N, de Coo R, Catsman-Berrevoets C, Grasshoff U, Kattentidt-Mouravieva A, Calf H, de Vreugt-Gronloh E, van Unen L, Verheijen FW, Galjart N, Morris-Rosendahl DJ, Mancini GMS. Severe presentation ofWDR62mutation: Is there a role for modifying genetic factors? Am J Med Genet A 2014; 164A:2161-71. [DOI: 10.1002/ajmg.a.36611] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 04/06/2014] [Indexed: 11/09/2022]
Affiliation(s)
- Cathryn J. Poulton
- Department of Clinical Genetics; Erasmus Medical Center; Rotterdam Germany
| | - Rachel Schot
- Department of Clinical Genetics; Erasmus Medical Center; Rotterdam Germany
| | - Katja Seufert
- Institute of Human Genetics; Albert-Ludwigs University Medical Centre Freiburg; Freiburg Germany
| | | | - Andrea Accogli
- Department of Pediatrics; Gaslini Institute; Genova Italy
| | | | | | - Nicole Philip
- Inserm U910; Aix Marseille University; Marseille France
| | - René de Coo
- Department of Child Neurology; Erasmus Medical Center; Rotterdam Germany
| | | | - Ute Grasshoff
- Institute of Medical Genetics and Applied Genomics; University Hospital Tuebingen; Tuebingen Germany
| | | | - Hans Calf
- ASVZ Zuid West; Rotterdam the Netherlands
| | | | - Leontine van Unen
- Department of Clinical Genetics; Erasmus Medical Center; Rotterdam Germany
| | - Frans W. Verheijen
- Department of Clinical Genetics; Erasmus Medical Center; Rotterdam Germany
| | - Niels Galjart
- Department of Cell Biology; Erasmus Medical Center; Rotterdam the Netherlands
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576
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Costagli M, Kelley DAC, Symms MR, Biagi L, Stara R, Maggioni E, Tiberi G, Barba C, Guerrini R, Cosottini M, Tosetti M. Tissue Border Enhancement by inversion recovery MRI at 7.0 Tesla. Neuroradiology 2014; 56:517-23. [DOI: 10.1007/s00234-014-1365-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 04/08/2014] [Indexed: 10/25/2022]
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577
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578
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Rossini L, Medici V, Tassi L, Cardinale F, Tringali G, Bramerio M, Villani F, Spreafico R, Garbelli R. Layer-specific gene expression in epileptogenic type II focal cortical dysplasia: normal-looking neurons reveal the presence of a hidden laminar organization. Acta Neuropathol Commun 2014; 2:45. [PMID: 24735483 PMCID: PMC4023625 DOI: 10.1186/2051-5960-2-45] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 04/04/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Type II focal cortical dysplasias (FCDs) are malformations of cortical development characterised by the disorganisation of the normal neocortical structure and the presence of dysmorphic neurons (DNs) and balloon cells (BCs). The pathogenesis of FCDs has not yet been clearly established, although a number of histopathological patterns and molecular findings suggest that they may be due to abnormal neuronal and glial proliferation and migration processes.In order to gain further insights into cortical layering disruption and investigate the origin of DNs and BCs, we used in situ RNA hybridisation of human surgical specimens with a neuropathologically definite diagnosis of Type IIa/b FCD and a panel of layer-specific genes (LSGs) whose expression covers all cortical layers. We also used anti-phospho-S6 ribosomal protein antibody to investigate mTOR pathway hyperactivation. RESULTS LSGs were expressed in both normal and abnormal cells (BCs and DNs) but their distribution was different. Normal-looking neurons, which were visibly reduced in the core of the lesion, were apparently located in the appropriate cortical laminae thus indicating a partial laminar organisation. On the contrary, DNs and BCs, labelled with anti-phospho-S6 ribosomal protein antibody, were spread throughout the cortex without any apparent rule and showed a highly variable LSG expression pattern. Moreover, LSGs did not reveal any differences between Type IIa and IIb FCD. CONCLUSION These findings suggest the existence of hidden cortical lamination involving normal-looking neurons, which retain their ability to migrate correctly in the cortex, unlike DNs which, in addition to their morphological abnormalities and mTOR hyperactivation, show an altered migratory pattern.Taken together these data suggest that an external or environmental hit affecting selected precursor cells during the very early stages of cortical development may disrupt normal cortical development.
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Affiliation(s)
- Laura Rossini
- Clinical Epileptology and Experimental Neurophysiology Unit, Istituto Neurologico “C. Besta”, Via Amadeo 42, 20133 Milano, Italy
| | - Valentina Medici
- Clinical Epileptology and Experimental Neurophysiology Unit, Istituto Neurologico “C. Besta”, Via Amadeo 42, 20133 Milano, Italy
| | - Laura Tassi
- C. Munari Epilepsy Surgery Centre, Niguarda Hospital, Milan, Italy
| | | | - Giovanni Tringali
- Department of Neurosurgery, Fondazione IRCCS, Istituto Neurologico “C. Besta”, Milan, Italy
| | | | - Flavio Villani
- Clinical Epileptology and Experimental Neurophysiology Unit, Istituto Neurologico “C. Besta”, Via Amadeo 42, 20133 Milano, Italy
| | - Roberto Spreafico
- Clinical Epileptology and Experimental Neurophysiology Unit, Istituto Neurologico “C. Besta”, Via Amadeo 42, 20133 Milano, Italy
| | - Rita Garbelli
- Clinical Epileptology and Experimental Neurophysiology Unit, Istituto Neurologico “C. Besta”, Via Amadeo 42, 20133 Milano, Italy
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579
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Scheffer IE, Heron SE, Regan BM, Mandelstam S, Crompton DE, Hodgson BL, Licchetta L, Provini F, Bisulli F, Vadlamudi L, Gecz J, Connelly A, Tinuper P, Ricos MG, Berkovic SF, Dibbens LM. Mutations in mammalian target of rapamycin regulatorDEPDC5cause focal epilepsy with brain malformations. Ann Neurol 2014; 75:782-7. [DOI: 10.1002/ana.24126] [Citation(s) in RCA: 164] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 01/14/2014] [Accepted: 02/26/2014] [Indexed: 11/09/2022]
Affiliation(s)
- Ingrid E. Scheffer
- Epilepsy Research Centre; Department of Medicine; University of Melbourne; Austin Health Melbourne Australia
- Florey Institute of Neuroscience and Mental Health; Melbourne Australia
- Department of Paediatrics; University of Melbourne; Royal Children's Hospital Melbourne Australia
| | - Sarah E. Heron
- Epilepsy Research Program; School of Pharmacy and Medical Sciences; University of South Australia; Adelaide Australia
- Sansom Institute for Health Research, University of South Australia; Adelaide Australia
| | - Brigid M. Regan
- Epilepsy Research Centre; Department of Medicine; University of Melbourne; Austin Health Melbourne Australia
| | - Simone Mandelstam
- Florey Institute of Neuroscience and Mental Health; Melbourne Australia
- Department of Paediatrics; University of Melbourne; Royal Children's Hospital Melbourne Australia
- Department of Radiology; University of Melbourne; Royal Children's Hospital Melbourne Australia
| | | | - Bree L. Hodgson
- Epilepsy Research Program; School of Pharmacy and Medical Sciences; University of South Australia; Adelaide Australia
- Sansom Institute for Health Research, University of South Australia; Adelaide Australia
| | - Laura Licchetta
- IRCCS, Institute of Neurological Science, University of Bologna; Bologna Italy
| | - Federica Provini
- IRCCS, Institute of Neurological Science, University of Bologna; Bologna Italy
- Department of Biomedical and Neuromotor Sciences; University of Bologna; Bologna Italy
| | - Francesca Bisulli
- IRCCS, Institute of Neurological Science, University of Bologna; Bologna Italy
- Department of Biomedical and Neuromotor Sciences; University of Bologna; Bologna Italy
| | - Lata Vadlamudi
- Epilepsy Research Centre; Department of Medicine; University of Melbourne; Austin Health Melbourne Australia
- School of Medicine, University of Queensland and Department of Neurology; Royal Brisbane and Women's Hospital Brisbane Australia
| | - Jozef Gecz
- School of Paediatrics and Reproductive Health; University of Adelaide; Adelaide Australia
| | - Alan Connelly
- Florey Institute of Neuroscience and Mental Health; Melbourne Australia
- Department of Medicine; Austin Health, University of Melbourne; Melbourne Australia
| | - Paolo Tinuper
- IRCCS, Institute of Neurological Science, University of Bologna; Bologna Italy
- Department of Biomedical and Neuromotor Sciences; University of Bologna; Bologna Italy
| | - Michael G. Ricos
- Epilepsy Research Program; School of Pharmacy and Medical Sciences; University of South Australia; Adelaide Australia
- Sansom Institute for Health Research, University of South Australia; Adelaide Australia
| | - Samuel F. Berkovic
- Epilepsy Research Centre; Department of Medicine; University of Melbourne; Austin Health Melbourne Australia
| | - Leanne M. Dibbens
- Epilepsy Research Program; School of Pharmacy and Medical Sciences; University of South Australia; Adelaide Australia
- Sansom Institute for Health Research, University of South Australia; Adelaide Australia
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580
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Cid E, Gomez-Dominguez D, Martin-Lopez D, Gal B, Laurent F, Ibarz JM, Francis F, Menendez de la Prida L. Dampened hippocampal oscillations and enhanced spindle activity in an asymptomatic model of developmental cortical malformations. Front Syst Neurosci 2014; 8:50. [PMID: 24782720 PMCID: PMC3995045 DOI: 10.3389/fnsys.2014.00050] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 03/18/2014] [Indexed: 11/13/2022] Open
Abstract
Developmental cortical malformations comprise a large spectrum of histopathological brain abnormalities and syndromes. Their genetic, developmental and clinical complexity suggests they should be better understood in terms of the complementary action of independently timed perturbations (i.e., the multiple-hit hypothesis). However, understanding the underlying biological processes remains puzzling. Here we induced developmental cortical malformations in offspring, after intraventricular injection of methylazoxymethanol (MAM) in utero in mice. We combined extensive histological and electrophysiological studies to characterize the model. We found that MAM injections at E14 and E15 induced a range of cortical and hippocampal malformations resembling histological alterations of specific genetic mutations and transplacental mitotoxic agent injections. However, in contrast to most of these models, intraventricularly MAM-injected mice remained asymptomatic and showed no clear epilepsy-related phenotype as tested in long-term chronic recordings and with pharmacological manipulations. Instead, they exhibited a non-specific reduction of hippocampal-related brain oscillations (mostly in CA1); including theta, gamma and HFOs; and enhanced thalamocortical spindle activity during non-REM sleep. These data suggest that developmental cortical malformations do not necessarily correlate with epileptiform activity. We propose that the intraventricular in utero MAM approach exhibiting a range of rhythmopathies is a suitable model for multiple-hit studies of associated neurological disorders.
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Affiliation(s)
- Elena Cid
- Laboratorio de Circuitos Neuronales, Instituto Cajal, CSIC Madrid, Spain
| | | | - David Martin-Lopez
- Laboratorio de Circuitos Neuronales, Instituto Cajal, CSIC Madrid, Spain ; Servicio de Neurofisiologia Clínica, Hospital General Universitario Gregorio Marañón Madrid, Spain
| | - Beatriz Gal
- Laboratorio de Circuitos Neuronales, Instituto Cajal, CSIC Madrid, Spain ; Universidad Europea de Madrid, Ciencias Biomédicas Básicas Madrid, Spain
| | - François Laurent
- Laboratorio de Circuitos Neuronales, Instituto Cajal, CSIC Madrid, Spain
| | - Jose M Ibarz
- Servicio de Neurobiología, Instituto Ramón y Cajal de Investigación Sanitaria Madrid, Spain
| | - Fiona Francis
- Institut du Fer à Moulin Paris, France ; Sorbonne Universités, Université Pierre et Marie Curie Paris, France ; Institut National de la Santé et de la Recherche Médicale UMRS 839 Paris, France
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Wilmshurst JM, Berg AT, Lagae L, Newton CR, Cross JH. The challenges and innovations for therapy in children with epilepsy. Nat Rev Neurol 2014; 10:249-60. [PMID: 24709890 DOI: 10.1038/nrneurol.2014.58] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Major advances have been made in the diagnosis, evaluation and management of children with epilepsy over the past 15 years. There has been a marked increase in genetic diagnoses of a number of key childhood-onset epilepsy syndromes, such as Dravet syndrome, which has been linked to mutations in the SCN1A gene. The reorganization and reclassification of epilepsies, devised by the International League Against Epilepsy, has stimulated specialists to reassess their diagnostic practices; however, many studies have not addressed the global issues in treating children with epilepsy-specifically, the challenges of diagnosis through to optimal, and appropriate, therapeutic management. Also, Class I evidence-based data that are needed as a foundation for the development of treatment guidelines worldwide are lacking. Epilepsy is common, and the impact of this disease crosses age ranges and should be managed at all levels of care from community to quaternary care. In this Review, existing data and new therapeutic management approaches are discussed with the aim of highlighting the incidence of standard practices that may not be based on clinical evidence.
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Affiliation(s)
- Jo M Wilmshurst
- Red Cross War Memorial Children's Hospital, University of Cape Town, Rondebosch 7700, South Africa
| | - Anne T Berg
- Ann & Robert H. Lurie Children's Hospital of Chicago, 225 East Chicago Avenue, Chicago, IL 60611, USA
| | - Lieven Lagae
- Department of Pediatric Neurology, University Hospitals Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Charles R Newton
- Centre for Geographic Medicine Research-Coast, Kenya Medical Research Institute, PO Box 230, Kilifi 80108, Kenya
| | - J Helen Cross
- UCL Institute of Child Health, 4/5 Long Yard, London WC1N 3LU, UK
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Cushion TD, Paciorkowski AR, Pilz DT, Mullins JGL, Seltzer LE, Marion RW, Tuttle E, Ghoneim D, Christian SL, Chung SK, Rees MI, Dobyns WB. De novo mutations in the beta-tubulin gene TUBB2A cause simplified gyral patterning and infantile-onset epilepsy. Am J Hum Genet 2014; 94:634-41. [PMID: 24702957 DOI: 10.1016/j.ajhg.2014.03.009] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Accepted: 03/14/2014] [Indexed: 12/22/2022] Open
Abstract
Tubulins, and microtubule polymers into which they incorporate, play critical mechanical roles in neuronal function during cell proliferation, neuronal migration, and postmigrational development: the three major overlapping events of mammalian cerebral cortex development. A number of neuronally expressed tubulin genes are associated with a spectrum of disorders affecting cerebral cortex formation. Such "tubulinopathies" include lissencephaly/pachygyria, polymicrogyria-like malformations, and simplified gyral patterns, in addition to characteristic extracortical features, such as corpus callosal, basal ganglia, and cerebellar abnormalities. Epilepsy is a common finding in these related disorders. Here we describe two unrelated individuals with infantile-onset epilepsy and abnormalities of brain morphology, harboring de novo variants that affect adjacent amino acids in a beta-tubulin gene TUBB2A. Located in a highly conserved loop, we demonstrate impaired tubulin and microtubule function resulting from each variant in vitro and by using in silico predictive modeling. We propose that the affected functional loop directly associates with the alpha-tubulin-bound guanosine triphosphate (GTP) molecule, impairing the intradimer interface and correct formation of the alpha/beta-tubulin heterodimer. This study associates mutations in TUBB2A with the spectrum of "tubulinopathy" phenotypes. As a consequence, genetic variations affecting all beta-tubulin genes expressed at high levels in the brain (TUBB2B, TUBB3, TUBB, TUBB4A, and TUBB2A) have been linked with malformations of cortical development.
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Affiliation(s)
- Thomas D Cushion
- Neurology and Molecular Neuroscience Research Group, Institute of Life Science, College of Medicine, Swansea University, Swansea SA2 8PP, UK
| | - Alex R Paciorkowski
- Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642, USA; Departments of Pediatrics and Biomedical Genetics, University of Rochester Medical Center, Rochester, NY 14641, USA; Center for Neural Development & Disease, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Daniela T Pilz
- Institute of Medical Genetics, University Hospital of Wales, Cardiff CF14 4XW, UK; Wales Epilepsy Research Network (WERN), College of Medicine, Swansea University, Swansea SA2 8PP, UK
| | - Jonathan G L Mullins
- Neurology and Molecular Neuroscience Research Group, Institute of Life Science, College of Medicine, Swansea University, Swansea SA2 8PP, UK
| | - Laurie E Seltzer
- Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Robert W Marion
- The Children's Hospital at Montefiore, Bronx, NY 10467-2403, USA
| | - Emily Tuttle
- Center for Neural Development & Disease, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Dalia Ghoneim
- Center for Neural Development & Disease, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Susan L Christian
- Center for Integrative Brain Research, Seattle Children's Hospital, Seattle, WA 98101, USA
| | - Seo-Kyung Chung
- Neurology and Molecular Neuroscience Research Group, Institute of Life Science, College of Medicine, Swansea University, Swansea SA2 8PP, UK; Wales Epilepsy Research Network (WERN), College of Medicine, Swansea University, Swansea SA2 8PP, UK
| | - Mark I Rees
- Neurology and Molecular Neuroscience Research Group, Institute of Life Science, College of Medicine, Swansea University, Swansea SA2 8PP, UK; Wales Epilepsy Research Network (WERN), College of Medicine, Swansea University, Swansea SA2 8PP, UK.
| | - William B Dobyns
- Center for Integrative Brain Research, Seattle Children's Hospital, Seattle, WA 98101, USA; Departments of Pediatrics and Neurology, University of Washington, Seattle, WA 98195, USA.
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583
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Mirzaa GM, Millen KJ, Barkovich AJ, Dobyns WB, Paciorkowski AR. The Developmental Brain Disorders Database (DBDB): a curated neurogenetics knowledge base with clinical and research applications. Am J Med Genet A 2014; 164A:1503-11. [PMID: 24700709 DOI: 10.1002/ajmg.a.36517] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 02/05/2014] [Indexed: 11/08/2022]
Abstract
The number of single genes associated with neurodevelopmental disorders has increased dramatically over the past decade. The identification of causative genes for these disorders is important to clinical outcome as it allows for accurate assessment of prognosis, genetic counseling, delineation of natural history, inclusion in clinical trials, and in some cases determines therapy. Clinicians face the challenge of correctly identifying neurodevelopmental phenotypes, recognizing syndromes, and prioritizing the best candidate genes for testing. However, there is no central repository of definitions for many phenotypes, leading to errors of diagnosis. Additionally, there is no system of levels of evidence linking genes to phenotypes, making it difficult for clinicians to know which genes are most strongly associated with a given condition. We have developed the Developmental Brain Disorders Database (DBDB: https://www.dbdb.urmc.rochester.edu/home), a publicly available, online-curated repository of genes, phenotypes, and syndromes associated with neurodevelopmental disorders. DBDB contains the first referenced ontology of developmental brain phenotypes, and uses a novel system of levels of evidence for gene-phenotype associations. It is intended to assist clinicians in arriving at the correct diagnosis, select the most appropriate genetic test for that phenotype, and improve the care of patients with developmental brain disorders. For researchers interested in the discovery of novel genes for developmental brain disorders, DBDB provides a well-curated source of important genes against which research sequencing results can be compared. Finally, DBDB allows novel observations about the landscape of the neurogenetics knowledge base.
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Affiliation(s)
- Ghayda M Mirzaa
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington; Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, Washington
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584
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Zhang X, Ling J, Barcia G, Jing L, Wu J, Barry BJ, Mochida GH, Hill RS, Weimer JM, Stein Q, Poduri A, Partlow JN, Ville D, Dulac O, Yu TW, Lam ATN, Servattalab S, Rodriguez J, Boddaert N, Munnich A, Colleaux L, Zon LI, Söll D, Walsh CA, Nabbout R. Mutations in QARS, encoding glutaminyl-tRNA synthetase, cause progressive microcephaly, cerebral-cerebellar atrophy, and intractable seizures. Am J Hum Genet 2014; 94:547-58. [PMID: 24656866 DOI: 10.1016/j.ajhg.2014.03.003] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 03/05/2014] [Indexed: 01/30/2023] Open
Abstract
Progressive microcephaly is a heterogeneous condition with causes including mutations in genes encoding regulators of neuronal survival. Here, we report the identification of mutations in QARS (encoding glutaminyl-tRNA synthetase [QARS]) as the causative variants in two unrelated families affected by progressive microcephaly, severe seizures in infancy, atrophy of the cerebral cortex and cerebellar vermis, and mild atrophy of the cerebellar hemispheres. Whole-exome sequencing of individuals from each family independently identified compound-heterozygous mutations in QARS as the only candidate causative variants. QARS was highly expressed in the developing fetal human cerebral cortex in many cell types. The four QARS mutations altered highly conserved amino acids, and the aminoacylation activity of QARS was significantly impaired in mutant cell lines. Variants p.Gly45Val and p.Tyr57His were located in the N-terminal domain required for QARS interaction with proteins in the multisynthetase complex and potentially with glutamine tRNA, and recombinant QARS proteins bearing either substitution showed an over 10-fold reduction in aminoacylation activity. Conversely, variants p.Arg403Trp and p.Arg515Trp, each occurring in a different family, were located in the catalytic core and completely disrupted QARS aminoacylation activity in vitro. Furthermore, p.Arg403Trp and p.Arg515Trp rendered QARS less soluble, and p.Arg403Trp disrupted QARS-RARS (arginyl-tRNA synthetase 1) interaction. In zebrafish, homozygous qars loss of function caused decreased brain and eye size and extensive cell death in the brain. Our results highlight the importance of QARS during brain development and that epilepsy due to impairment of QARS activity is unusually severe in comparison to other aminoacyl-tRNA synthetase disorders.
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Affiliation(s)
- Xiaochang Zhang
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute
| | - Jiqiang Ling
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8114, USA; Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Giulia Barcia
- Department of Pediatric Neurology, Centre de Reference Epilepsies Rares, Hôpital Necker-Enfants Malades, Assistance Publique-Hôpitaux de Paris, 75015 Paris, France; Institut National de la Santé et de la Recherche Médicale U1129, Université Paris Descartes, 75006 Paris, France; Institut National de la Santé et de la Recherche Médicale U1129, NeuroSpin, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, 91191 Gif-sur-Yvette, France
| | - Lili Jing
- Howard Hughes Medical Institute; Stem Cell Program and Division of Hematology/Oncology, Boston Children's Hospital, Harvard Stem Cell Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Jiang Wu
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Brenda J Barry
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute
| | - Ganeshwaran H Mochida
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, MA 02115, USA; Pediatric Neurology Unit, Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - R Sean Hill
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute
| | - Jill M Weimer
- Sanford Children's Health Research Center, Sanford Research, 2301 East 60(th) Street North, Sioux Falls, SD 57104, USA
| | - Quinn Stein
- Departments of Pediatrics and Ob/Gyn, Sanford School of Medicine, Sioux Falls, SD 57105, USA
| | - Annapurna Poduri
- Department of Neurology, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - Jennifer N Partlow
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute
| | - Dorothée Ville
- Department of Pediatric Neurology, Centre Hospitalier Universitaire de Lyon, 69007 Lyon, France
| | - Olivier Dulac
- Department of Pediatric Neurology, Centre de Reference Epilepsies Rares, Hôpital Necker-Enfants Malades, Assistance Publique-Hôpitaux de Paris, 75015 Paris, France; Institut National de la Santé et de la Recherche Médicale U1129, Université Paris Descartes, 75006 Paris, France; Institut National de la Santé et de la Recherche Médicale U1129, NeuroSpin, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, 91191 Gif-sur-Yvette, France
| | - Tim W Yu
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Anh-Thu N Lam
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute
| | - Sarah Servattalab
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute
| | - Jacqueline Rodriguez
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute
| | - Nathalie Boddaert
- Institut National de la Santé et de la Recherche Médicale U781, Department of Pediatric Radiology, Hôpital Necker-Enfants Malades, Imagine institute, Université Paris Descartes, 75006 Paris, France
| | - Arnold Munnich
- Institut National de la Santé et de la Recherche Médicale U781, Department of Genetics, Hôpital Necker-Enfants Malades, Imagine institute, Université Paris Descartes, 75006 Paris, France
| | - Laurence Colleaux
- Institut National de la Santé et de la Recherche Médicale U781, Department of Genetics, Hôpital Necker-Enfants Malades, Imagine institute, Université Paris Descartes, 75006 Paris, France
| | - Leonard I Zon
- Howard Hughes Medical Institute; Stem Cell Program and Division of Hematology/Oncology, Boston Children's Hospital, Harvard Stem Cell Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Dieter Söll
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8114, USA
| | - Christopher A Walsh
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute; Department of Pediatrics, Harvard Medical School, MA 02115, USA; Department of Neurology, Harvard Medical School, Boston, MA 02115, USA; Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Rima Nabbout
- Department of Pediatric Neurology, Centre de Reference Epilepsies Rares, Hôpital Necker-Enfants Malades, Assistance Publique-Hôpitaux de Paris, 75015 Paris, France; Institut National de la Santé et de la Recherche Médicale U1129, Université Paris Descartes, 75006 Paris, France; Institut National de la Santé et de la Recherche Médicale U1129, NeuroSpin, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, 91191 Gif-sur-Yvette, France.
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585
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Aronica E, Crino PB. Epilepsy related to developmental tumors and malformations of cortical development. Neurotherapeutics 2014; 11:251-68. [PMID: 24481729 PMCID: PMC3996119 DOI: 10.1007/s13311-013-0251-0] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Structural abnormalities of the brain are increasingly recognized in patients with neurodevelopmental delay and intractable focal epilepsies. The access to clinically well-characterized neurosurgical material has provided a unique opportunity to better define the neuropathological, neurochemical, and molecular features of epilepsy-associated focal developmental lesions. These studies help to further understand the epileptogenic mechanisms of these lesions. Neuropathological evaluation of surgical specimens from patients with epilepsy-associated developmental lesions reveals two major pathologies: focal cortical dysplasia and low-grade developmental tumors (glioneuronal tumors). In the last few years there have been major advances in the recognition of a wide spectrum of developmental lesions associated with a intractable epilepsy, including cortical tubers in patients with tuberous sclerosis complex and hemimegalencephaly. As an increasing number of entities are identified, the development of a unified and comprehensive classification represents a great challenge and requires continuous updates. The present article reviews current knowledge of molecular pathogenesis and the pathophysiological mechanisms of epileptogenesis in this group of developmental disorders. Both emerging neuropathological and basic science evidence will be analyzed, highlighting the involvement of different, but often converging, pathogenetic and epileptogenic mechanisms, which may create the basis for new therapeutic strategies in these disorders.
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Affiliation(s)
- Eleonora Aronica
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105, AZ, Amsterdam, The Netherlands,
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586
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Romaniello R, Arrigoni F, Cavallini A, Tenderini E, Baschirotto C, Triulzi F, Bassi MT, Borgatti R. Brain malformations and mutations in α- and β-tubulin genes: a review of the literature and description of two new cases. Dev Med Child Neurol 2014; 56:354-60. [PMID: 24392928 DOI: 10.1111/dmcn.12370] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/06/2013] [Indexed: 11/29/2022]
Abstract
AIM The aim of this study was to determine the frequency of mutations in tubulin genes (TUBB2B, TUBA1A, and TUBB3) in patients with malformations of cortical development (MCDs) of unknown origin. METHOD In total, 79 out of 156 patients (41 males, 38 females; age range 8mo-55y (mean age 13y 3mo, SD 11y 2mo) with a neuroradiological diagnosis of MCDs were enrolled in the study. The 77 excluded patients were excluded for the following reasons: suspected or proven diagnosis of pre- or perinatal ischaemic insult (n=13); syndromic disease (n=10); congenital infection (n=14); pregnancy complicated by twin-to-twin transfusion syndrome (n=2); proven mutations in known genes (n=13); poor magnetic resonance imaging (MRI) quality, or lack of informed consent (n=25). A genetic analysis of the TUBA1A, TUBB2B and TUBB3 genes was carried out by direct sequencing of the coding regions of the relevant genes for each participant. Previously described patients with mutations in the TUBB2B and TUBA1A genes were reviewed; clinical and neuroradiological findings were compared and discussed. RESULTS Two novel heterozygous mutations were detected: a heterozygous mutation in exon 4 of the TUBA1A gene (c.1160C>T) in a 5-year-old female with microcephaly, severe intellectual disability, and absence of language, and a c.1080 _1084del CCTGAinsACATCTTC in exon 4 of the TUBB2B gene in a 31-year-old female with microcephaly, spastic tetraparesis, severe intellectual disability, and scoliosis. Different types of cortical abnormalities, cerebellar vermis hypoplasia, and optic nerve hypoplasia/atrophy were detected on MRI. Dysmorphisms of the basal ganglia and the hippocampi with abnormalities of the midline commissural structures were present in both cases. INTERPRETATION The consistent presence of hypoplastic and disorganized white matter tracts suggests that, in addition to defects in neuronal migration, disruption of axon growth and guidance is a peculiar feature of tubulin-related disorders.
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Affiliation(s)
- Romina Romaniello
- Neuropsychiatry and Neurorehabilitation Unit, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
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587
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Adachi Y, Mochida G, Walsh C, Barkovich J. Posterior fossa in primary microcephaly: relationships between forebrain and mid-hindbrain size in 110 patients. Neuropediatrics 2014; 45:93-101. [PMID: 24234199 PMCID: PMC8815106 DOI: 10.1055/s-0033-1360483] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Microcephalies vary widely in clinical severity and in morphology. The purpose of this study is to determine the frequency of disproportion between the size of the cerebrum and the size of midbrain and hindbrain structures in infants and children with microcephaly, as analysis of such disproportions might aid understanding of these disorders and facilitate testing for specific genetic causes. The relative sizes of the forebrain, each component of the brain stem, and vermis and hemispheres of the cerebellum were analyzed visually on magnetic resonance (MR) images of 110 microcephalic patients. A disproportionally large cerebellum, compared with the cerebrum, was found in 50 cases (45.5%), a proportional cerebellum in 49 cases (44.5%), and a disproportionally small cerebellum in 11 cases (10%). Proportional cerebella were most common in mild (86%) and moderate (55%) microcephaly patients, whereas disproportionately large cerebella were most common in severe (57%) and moderate (32%) microcephaly. Disproportionately small cerebella were seen only in moderate (13%) and severe (9%) microcephaly. As genes are expressed at different times in cerebral and cerebellar development, it is postulated that analysis of relative cerebellar and brain stem size may be useful in the initial analysis of microcephaly by MR images both to categorize and to help determine likely genetic causes.
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Affiliation(s)
- Yuko Adachi
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, United States
| | - Ganeshwaran Mochida
- Division of Genetics, Manton Center for Orphan Disease Research, Boston, Massachusetts, United States
| | - Christopher Walsh
- Division of Genetics, Manton Center for Orphan Disease Research, Boston, Massachusetts, United States
| | - James Barkovich
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, United States
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588
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Baulac S, Lenk GM, Dufresnois B, Ouled Amar Bencheikh B, Couarch P, Renard J, Larson PA, Ferguson CJ, Noé E, Poirier K, Hubans C, Ferreira S, Guerrini R, Ouazzani R, El Hachimi KH, Meisler MH, Leguern E. Role of the phosphoinositide phosphatase FIG4 gene in familial epilepsy with polymicrogyria. Neurology 2014; 82:1068-75. [PMID: 24598713 DOI: 10.1212/wnl.0000000000000241] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE The aim of this study was to identify the causal gene in a consanguineous Moroccan family with temporo-occipital polymicrogyria, psychiatric manifestations, and epilepsy, previously mapped to the 6q16-q22 region. METHODS We used exome sequencing and analyzed candidate variants in the 6q16-q22 locus, as well as a rescue assay in Fig4-null mouse fibroblasts and immunohistochemistry of Fig4-null mouse brains. RESULTS A homozygous missense mutation (p.Asp783Val) in the phosphoinositide phosphatase gene FIG4 was identified. Pathogenicity of the variant was supported by impaired rescue of the enlarged vacuoles in transfected fibroblasts from Fig4-deficient mice. Histologic examination of Fig4-null mouse brain revealed neurodevelopmental impairment in the hippocampus, cortex, and cerebellum as well as impaired cerebellar gyration/foliation reminiscent of human cortical malformations. CONCLUSIONS This study extends the spectrum of phenotypes associated with FIG4 mutations to include cortical malformation associated with seizures and psychiatric manifestations, in addition to the previously described Charcot-Marie-Tooth disease type 4J and Yunis-Varón syndrome.
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Affiliation(s)
- Stéphanie Baulac
- From INSERM (S.B., B.D., B.O.A.B., P.C., J.R., E.N., K.H.E.H., E.L.), U1127; Sorbonne Universités, UPMC Univ Paris 06 (S.B., B.D., B.O.A.B., P.C., J.R., E.N., K.H.E.H., E.L.), UM 75; CNRS (S.B., B.D., B.O.A.B., P.C., J.R., E.N., K.H.E.H., E.L.), UMR 7225, ICM, Paris, ICM, (S.B., B.D., B.O.A.B., P.C., J.R., E.N., K.H.E.H., E.L.) Paris, F-75013 Paris, France; Department of Human Genetics (G.M.L., P.A.L., C.J.F., M.H.M.), University of Michigan, Ann Arbor; Service de Neurophysiologie Clinique (B.O.A.B.), Hôpital des Spécialités, Centre Hospitalier Ibn Sina Rabat, Morocco; Genetics and Pathophysiology of Neurodevelopmental and Neuromuscular Diseases (K.P.), Cochin Institute, Paris; GenoScreen (C.H., S.F.), Lille, France; Neuroscience Department (R.G.), Children's Hospital A. Meyer, University of Florence and IRCCS Stella Maris, Pisa, Italy; Laboratoire de Neurogénétique (K.H.E.H.), Ecole Pratique des Hautes Etudes, Paris; and Département de Génétique et de Cytogénétique (E.L.), AP-HP Groupe hospitalier Pitié-Salpêtrière, Paris, France
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589
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Colciaghi F, Finardi A, Nobili P, Locatelli D, Spigolon G, Battaglia GS. Progressive brain damage, synaptic reorganization and NMDA activation in a model of epileptogenic cortical dysplasia. PLoS One 2014; 9:e89898. [PMID: 24587109 PMCID: PMC3937400 DOI: 10.1371/journal.pone.0089898] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 01/28/2014] [Indexed: 01/17/2023] Open
Abstract
Whether severe epilepsy could be a progressive disorder remains as yet unresolved. We previously demonstrated in a rat model of acquired focal cortical dysplasia, the methylazoxymethanol/pilocarpine - MAM/pilocarpine - rats, that the occurrence of status epilepticus (SE) and subsequent seizures fostered a pathologic process capable of modifying the morphology of cortical pyramidal neurons and NMDA receptor expression/localization. We have here extended our analysis by evaluating neocortical and hippocampal changes in MAM/pilocarpine rats at different epilepsy stages, from few days after onset up to six months of chronic epilepsy. Our findings indicate that the process triggered by SE and subsequent seizures in the malformed brain i) is steadily progressive, deeply altering neocortical and hippocampal morphology, with atrophy of neocortex and CA regions and progressive increase of granule cell layer dispersion; ii) changes dramatically the fine morphology of neurons in neocortex and hippocampus, by increasing cell size and decreasing both dendrite arborization and spine density; iii) induces reorganization of glutamatergic and GABAergic networks in both neocortex and hippocampus, favoring excitatory vs inhibitory input; iv) activates NMDA regulatory subunits. Taken together, our data indicate that, at least in experimental models of brain malformations, severe seizure activity, i.e., SE plus recurrent seizures, may lead to a widespread, steadily progressive architectural, neuronal and synaptic reorganization in the brain. They also suggest the mechanistic relevance of glutamate/NMDA hyper-activation in the seizure-related brain pathologic plasticity.
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Affiliation(s)
- Francesca Colciaghi
- Molecular Neuroanatomy and Pathogenesis Unit, IRCCS Neurological Institute “C. Besta”, Milano, Italy
| | - Adele Finardi
- Molecular Neuroanatomy and Pathogenesis Unit, IRCCS Neurological Institute “C. Besta”, Milano, Italy
| | - Paola Nobili
- Molecular Neuroanatomy and Pathogenesis Unit, IRCCS Neurological Institute “C. Besta”, Milano, Italy
| | - Denise Locatelli
- Molecular Neuroanatomy and Pathogenesis Unit, IRCCS Neurological Institute “C. Besta”, Milano, Italy
| | - Giada Spigolon
- Neuroscience Institute Cavalieri Ottolenghi (NICO), University of Torino, Orbassano (Torino), Italy
| | - Giorgio Stefano Battaglia
- Molecular Neuroanatomy and Pathogenesis Unit, IRCCS Neurological Institute “C. Besta”, Milano, Italy
- * E-mail:
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590
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Schmuck M, Temme T, Heinz S, Baksmeier C, Mosig A, Colomina MT, Barenys M, Fritsche E. Automatic counting and positioning of 5-bromo-2-deoxyuridine (BrdU) positive cells in cortical layers of rat brain slices. Neurotoxicology 2014; 43:127-133. [PMID: 24572144 DOI: 10.1016/j.neuro.2014.02.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 02/13/2014] [Accepted: 02/14/2014] [Indexed: 11/15/2022]
Abstract
5-Bromo-2-deoxyuridine (BrdU) staining is often used to evaluate cortical layer formation during mammalian brain development. This method allows the quantification of newly generated cells and therefore the study of the effects of xenobiotics or genetic factors on proliferation, cell death and migration behavior in a quantitative manner. However, these endpoints are generally assessed by time-consuming manual evaluation. In the present work, we introduce a novel procedure to identify and quantify BrdU(+) cells within cortical layers, using the commercially available vHCS-Scan V.6.3.1 software to identify BrdU(+) cell coordinates and the novel program 'BrdeLuxe' to define cortical layers and quantitatively assign BrdU(+) cells to them. This procedure is compared to BrdU(+) cell counting with the freeware 'ImageJ' in respect to the manual evaluation, all by two different researchers. BrdeLuxe shows high accuracy and precision for the determination of total number of BrdU(+) cells compared to the manual counting, while ImageJ does not reach such results. Accuracy and precision are also higher for employing the BrdeLuxe program to evaluate the percentage of BrdU(+) cells per brain layer compared to ImageJ. In terms of running time, BrdeLuxe is the fastest method of the three making it more suitable for multiple brain slices analyses.
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Affiliation(s)
- Martin Schmuck
- IUF - Leibniz Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225 Düsseldorf, Germany
| | - Thomas Temme
- IUF - Leibniz Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225 Düsseldorf, Germany; Bioinformatics Group, Department of Biophysics, Ruhr-Universität Bochum, 44780, Germany
| | - Sabrina Heinz
- IUF - Leibniz Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225 Düsseldorf, Germany
| | - Christine Baksmeier
- IUF - Leibniz Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225 Düsseldorf, Germany
| | - Axel Mosig
- Bioinformatics Group, Department of Biophysics, Ruhr-Universität Bochum, 44780, Germany
| | - M Teresa Colomina
- Laboratory of Toxicology and Environmental Health/NEUROLAB, Department of Psychology, Universitat Rovira i Virgili, Campus Sescelades, 43007 Tarragona, Spain
| | - Marta Barenys
- IUF - Leibniz Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225 Düsseldorf, Germany
| | - Ellen Fritsche
- IUF - Leibniz Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225 Düsseldorf, Germany.
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591
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Leventer RJ, Jansen FE, Mandelstam SA, Ho A, Mohamed I, Sarnat HB, Kato M, Fukasawa T, Saitsu H, Matsumoto N, Itoh M, Kalnins RM, Chow CW, Harvey AS, Jackson GD, Crino PB, Berkovic SF, Scheffer IE. Is focal cortical dysplasia sporadic? Family evidence for genetic susceptibility. Epilepsia 2014; 55:e22-6. [DOI: 10.1111/epi.12533] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/02/2013] [Indexed: 02/01/2023]
Affiliation(s)
- Richard J. Leventer
- Department of Neurology; Royal Children's Hospital; Melbourne Victoria Australia
- Murdoch Childrens Research Institute; Melbourne Victoria Australia
- Department of Pediatrics; University of Melbourne; Melbourne Victoria Australia
| | - Floor E. Jansen
- Department of Pediatric Neurology; Rudolf Magnus Institute of Neurosciences; University Medical Center Utrecht; Utrecht The Netherlands
- Epilepsy Research Centre; University of Melbourne; Austin Health; Melbourne Victoria Australia
| | - Simone A. Mandelstam
- The Florey Institute of Neuroscience and Mental Health; Melbourne Victoria Australia
- Department of Radiology; University of Melbourne; Melbourne Victoria Australia
| | - Alice Ho
- Departments of Pediatrics and Clinical Neurosciences; Alberta Children's Hospital; University of Calgary; Calgary Alberta Canada
| | - Ismail Mohamed
- Department of Pediatrics; IWK Health Center; Dalhousie University; Halifax Nova Scotia Canada
| | - Harvey B. Sarnat
- Department of Pediatrics, Pathology, (Neuropathology) and Clinical Neurosciences; University of Calgary Faculty of Medicine; Alberta Children's Hospital; Calgary Alberta Canada
| | - Mitsuhiro Kato
- Department of Pediatrics; Yamagata University Faculty of Medicine; Yamagata Japan
| | | | - Hirotomo Saitsu
- Department of Human Genetics; Yokohama City University Graduate School of Medicine; Yokohama Japan
| | - Naomichi Matsumoto
- Department of Human Genetics; Yokohama City University Graduate School of Medicine; Yokohama Japan
| | - Masayuki Itoh
- Department of Mental Retardation and Birth Defect Research; National Institute of Neuroscience; National Center of Neurology and Psychiatry; Tokyo Japan
| | - Renate M. Kalnins
- Department of Anatomical Pathology; Austin Hospital; Melbourne Victoria Australia
- Department of Pathology; University of Melbourne; Melbourne Victoria Australia
| | - Chung W. Chow
- Department of Pediatrics; University of Melbourne; Melbourne Victoria Australia
- Department of Anatomical Pathology; Royal Children's Hospital; Melbourne Victoria Australia
| | - A. Simon Harvey
- Department of Neurology; Royal Children's Hospital; Melbourne Victoria Australia
- Murdoch Childrens Research Institute; Melbourne Victoria Australia
- Department of Pediatrics; University of Melbourne; Melbourne Victoria Australia
| | - Graeme D. Jackson
- Epilepsy Research Centre; University of Melbourne; Austin Health; Melbourne Victoria Australia
- Department of Radiology; University of Melbourne; Melbourne Victoria Australia
| | - Peter B. Crino
- Shriners Hospitals Pediatric Research Center; Temple University; Philadelphia Pennsylvania U.S.A
| | - Samuel F. Berkovic
- Epilepsy Research Centre; University of Melbourne; Austin Health; Melbourne Victoria Australia
| | - Ingrid E. Scheffer
- Department of Neurology; Royal Children's Hospital; Melbourne Victoria Australia
- Department of Pediatrics; University of Melbourne; Melbourne Victoria Australia
- Epilepsy Research Centre; University of Melbourne; Austin Health; Melbourne Victoria Australia
- Department of Radiology; University of Melbourne; Melbourne Victoria Australia
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592
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Edwards TJ, Sherr EH, Barkovich AJ, Richards LJ. Clinical, genetic and imaging findings identify new causes for corpus callosum development syndromes. ACTA ACUST UNITED AC 2014; 137:1579-613. [PMID: 24477430 DOI: 10.1093/brain/awt358] [Citation(s) in RCA: 215] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The corpus callosum is the largest fibre tract in the brain, connecting the two cerebral hemispheres, and thereby facilitating the integration of motor and sensory information from the two sides of the body as well as influencing higher cognition associated with executive function, social interaction and language. Agenesis of the corpus callosum is a common brain malformation that can occur either in isolation or in association with congenital syndromes. Understanding the causes of this condition will help improve our knowledge of the critical brain developmental mechanisms required for wiring the brain and provide potential avenues for therapies for callosal agenesis or related neurodevelopmental disorders. Improved genetic studies combined with mouse models and neuroimaging have rapidly expanded the diverse collection of copy number variations and single gene mutations associated with callosal agenesis. At the same time, advances in our understanding of the developmental mechanisms involved in corpus callosum formation have provided insights into the possible causes of these disorders. This review provides the first comprehensive classification of the clinical and genetic features of syndromes associated with callosal agenesis, and provides a genetic and developmental framework for the interpretation of future research that will guide the next advances in the field.
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Affiliation(s)
- Timothy J Edwards
- 1 Queensland Brain Institute, The University of Queensland, Brisbane, 4072, Australia2 Departments of Neurology and Pediatrics, The University of California and the Benioff Children's Hospital, CA, 94158, USA
| | - Elliott H Sherr
- 3 Departments of Pediatrics and Neurosurgery, Radiology and Biomedical Imaging, The University of California Children's Hospital, CA 94143, USA
| | - A James Barkovich
- 3 Departments of Pediatrics and Neurosurgery, Radiology and Biomedical Imaging, The University of California Children's Hospital, CA 94143, USA4 Departments of Paediatrics and Neurosurgery, Radiology and Biomedical Imaging, The University of California San Francisco and The Benioff Children's Hospital, CA 94143-0628 USA
| | - Linda J Richards
- 1 Queensland Brain Institute, The University of Queensland, Brisbane, 4072, Australia5 School of Biomedical Sciences, The University of Queensland, Brisbane, 4072, Australia
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593
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594
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Fiorillo C, Moro F, Yi J, Weil S, Brisca G, Astrea G, Severino M, Romano A, Battini R, Rossi A, Minetti C, Bruno C, Santorelli FM, Vallee R. Novel dynein DYNC1H1 neck and motor domain mutations link distal spinal muscular atrophy and abnormal cortical development. Hum Mutat 2014; 35:298-302. [PMID: 24307404 DOI: 10.1002/humu.22491] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 11/22/2013] [Indexed: 11/10/2022]
Abstract
DYNC1H1 encodes the heavy chain of cytoplasmic dynein 1, a motor protein complex implicated in retrograde axonal transport, neuronal migration, and other intracellular motility functions. Mutations in DYNC1H1 have been described in autosomal-dominant Charcot-Marie-Tooth type 2 and in families with distal spinal muscular atrophy (SMA) predominantly affecting the legs (SMA-LED). Recently, defects of cytoplasmic dynein 1 were also associated with a form of mental retardation and neuronal migration disorders. Here, we describe two unrelated patients presenting a combined phenotype of congenital motor neuron disease associated with focal areas of cortical malformation. In each patient, we identified a novel de novo mutation in DYNC1H1: c.3581A>G (p.Gln1194Arg) in one case and c.9142G>A (p.Glu3048Lys) in the other. The mutations lie in different domains of the dynein heavy chain, and are deleterious to protein function as indicated by assays for Golgi recovery after nocodazole washout in patient fibroblasts. Our results expand the set of pathological mutations in DYNC1H1, reinforce the role of cytoplasmic dynein in disorders of neuronal migration, and provide evidence for a syndrome including spinal nerve degeneration and brain developmental problems.
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Affiliation(s)
- Chiara Fiorillo
- Neuromuscular and Molecular Medicine Unit, Department of Developmental Neuroscience, IRCCS Stella Maris, Pisa, Italy
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595
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Congenital brain anomalies and chromosomal aberrations from the Zagreb Collection of human brains. Transl Neurosci 2014. [DOI: 10.2478/s13380-014-0231-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
AbstractThe Zagreb Collection of developing and adult human brains consists of approximately 1,300 brains of fetuses, children and adults that were collected following routine autopsies in the period from 1974 to 2014. The collection comprises brains of different normal developmental stages that may serve for investigation of normal human brain development. Previous studies on this material have led to several important contributions on human cortical development, such as the discovery of the transient fetal subplate zone. The Zagreb Collection, however, also contains approximately 100 brains with different anomalies including chromosomal aberrations such as Down syndrome. We have analyzed all the available material from the Zagreb Collection and identified 44 brains of fetuses and children with Down syndrome, 10 with Patau syndrome, 6 with Edwards syndrome as well as 7 holoprosencephalic, 7 hydrocephalic and 4 microcephalic brains. The largest part of the Collection is available for further research using modern genetic, immunocytochemical and imaging methods, especially magnetic resonance imaging. Furthermore, the histological slides from the Zagreb Collection are currently being digitally scanned and made available as virtual slides to general scientific audience. The Zagreb Collection represents unique and versatile resource for the future study of normal and abnormal human brain development.
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596
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Jovanov Milošević N, Judaš M, Aronica E, Kostovic I. Neural ECM in laminar organization and connectivity development in healthy and diseased human brain. PROGRESS IN BRAIN RESEARCH 2014; 214:159-78. [DOI: 10.1016/b978-0-444-63486-3.00007-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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597
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Battaglia G, Colciaghi F, Finardi A, Nobili P. Intrinsic epileptogenicity of dysplastic cortex: converging data from experimental models and human patients. Epilepsia 2013; 54 Suppl 6:33-6. [PMID: 24001068 DOI: 10.1111/epi.12272] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Focal cortical dysplasia (FCD) is a brain malformation associated with particularly severe drug-resistant epilepsy that often requires surgery for seizure control. The molecular basis for such enhanced propensity to seizure generation in FCD is not as yet elucidated. To investigate cellular and molecular bases of epileptogenic mechanisms and possible effect of severe epilepsy on the malformed cortex we have here performed a parallel analysis of a rat model of acquired cortical dysplasia previously established in our laboratory, i.e., the methylazoxymethanol/pilocarpine (MAM-PILO) rats, and surgical samples from patients with type IIB FCD. Data from the MAM-PILO rat model and human FCD samples reveal in both conditions: (1) that status epilepticus (SE) and/or seizures can further modify the cellular and molecular settings of the malformed cortex; (2) excitation/inhibition imbalance, and dysregulation of the N-methyl-d-aspartate/ membrane-associated guanylate kinase (NMDA/MAGUK) expression; (3) activation of cell death in neurons and glia. The data therefore highlight the mechanistic relevance of glutamate/NMDA hyperactivation in FCD epileptogenesis and suggest that epilepsy is a pathologic process capable of affecting structure and function of both neurons and glia.
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Affiliation(s)
- Giorgio Battaglia
- Molecular Neuroanatomy and Pathogenesis Unit, IRCCS Foundation Neurological Institute Carlo Besta, Via Libero Temolo 4, Milan, Italy.
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598
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Suárez-Vega A, Gutiérrez-Gil B, Cuchillo-Ibáñez I, Sáez-Valero J, Pérez V, García-Gámez E, Benavides J, Arranz JJ. Identification of a 31-bp deletion in the RELN gene causing lissencephaly with cerebellar hypoplasia in sheep. PLoS One 2013; 8:e81072. [PMID: 24260534 PMCID: PMC3834269 DOI: 10.1371/journal.pone.0081072] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 10/09/2013] [Indexed: 12/15/2022] Open
Abstract
Lissencephaly is an inherited developmental disorder in which neuronal migration is impaired. A type of lissencephaly associated with cerebellar hypoplasia (LCH) was diagnosed in a commercial flock of Spanish Churra sheep. The genotyping of 7 affected animals and 33 controls with the OvineSNP50 BeadChip enabled the localization of the causative mutation for ovine LCH to a 4.8-Mb interval on sheep chromosome 4 using genome-wide association and homozygosity mapping. The RELN gene, which is located within this interval, was considered a strong positional and functional candidate because it plays critical roles in neuronal migration and layer formation. By performing a sequencing analysis of this gene’s specific mRNA in a control lamb, we obtained the complete CDS of the ovine RELN gene. The cDNA sequence from an LCH-affected lamb revealed a deletion of 31 bp (c.5410_5440del) in predicted exon 36 of RELN, resulting in a premature termination codon. A functional analysis of this mutation revealed decreased levels of RELN mRNA and a lack of reelin protein in the brain cortex and blood of affected lambs. This mutation showed a complete concordance with the Mendelian recessive pattern of inheritance observed for the disease. The identification of the causal mutation of LCH in Churra sheep will facilitate the implementation of gene-assisted selection to detect heterozygous mutants, which will help breeders avoid at-risk matings in their flocks. Moreover, the identification of this naturally occurring RELN mutation provides an opportunity to use Churra sheep as a genetically characterized large animal model for the study of reelin functions in the developing and mature brain.
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Affiliation(s)
| | | | - Inmaculada Cuchillo-Ibáñez
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández, CSIC, Sant Joan d’Alacant, Alicante, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Universidad Miguel Hernández, Sant Joan d’Alacant, Alicante, Spain
| | - Javier Sáez-Valero
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández, CSIC, Sant Joan d’Alacant, Alicante, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Universidad Miguel Hernández, Sant Joan d’Alacant, Alicante, Spain
| | - Valentín Pérez
- Dpto. de Sanidad Animal, Universidad de León, León, León, Spain
- Instituto de Ganadería de Montaña, Universidad de León CSIC, Grulleros, León, Spain
| | | | - Julio Benavides
- Instituto de Ganadería de Montaña, Universidad de León CSIC, Grulleros, León, Spain
| | - Juan Jose Arranz
- Dpto. Producción Animal, Universidad de León, León, León, Spain
- * E-mail:
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599
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van Binsbergen E, Ellis RJ, Abdelmalik N, Jarvis J, Randhawa K, Wyatt-Ashmead J, Canham N, Thorpe-Beeston JG, Mancini GMS, Van Haelst MM. A fetus with de novo 2q33.2q35 deletion including MAP2 with brain anomalies, esophageal atresia, and laryngeal stenosis. Am J Med Genet A 2013; 164A:194-8. [PMID: 24243657 DOI: 10.1002/ajmg.a.36202] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 08/02/2013] [Indexed: 12/29/2022]
Abstract
Deletions of the long arm of chromosome 2 are rare. Few cases of interstitial deletions of the 2q33q35 region have been reported. Individuals with deletions in this region have growth retardation, psychomotor retardation, micrognathia, microcephaly, and apparently low-set ears. We describe a female fetus with a de novo deletion of 2q33.2 to q35 with delayed gyral formation with widespread neuronal heterotopia of the white matter, small cerebellum, esophageal atresia, laryngeal stenosis, micrognathia, and intrauterine growth retardation. With the use of karyotyping and high-resolution array comparative genomic hybridization the boundaries and gene content of the deletion were identified. Our aim was to determine whether a candidate gene for the brain phenotype was present in the deletion. By this means and based on literature we pinpointed the microtubule associated gene MAP2 as a candidate for the brain anomalies.
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Affiliation(s)
- Ellen van Binsbergen
- Department of Medical Genetics, University Medical Centre Utrecht, Utrecht, The Netherlands
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600
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Moroni RF, Inverardi F, Regondi MC, Pennacchio P, Spreafico R, Frassoni C. Genesis of heterotopia in BCNU model of cortical dysplasia, detected by means of in utero electroporation. Dev Neurosci 2013; 35:516-26. [PMID: 24246662 DOI: 10.1159/000355392] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 08/30/2013] [Indexed: 11/19/2022] Open
Abstract
Derangements of cortical development can cause a wide spectrum of malformations, generally termed 'cortical dysplasia' (CD), which are frequently associated with drug-resistant epilepsy and other neurological and mental disorders. 1,3-Bis-chloroethyl-nitrosurea (BCNU)-treated rats represent a model of CD due to the presence of histological alterations similar to those observed in human CD. BCNU is an alkylating agent that, administered at embryonic day 15 (E15), causes the loss of many cells destined to cortical layers; this results in cortical thinning but also in histological alterations imputable to migration defects, such as laminar disorganization and cortical and periventricular heterotopia. In the present study we investigated the genesis of heterotopia in BCNU-treated rats by labeling cortical ventricular zone (VZ) cells with a green fluorescent protein (GFP) expression vector by means of in utero electroporation. Here, we compared the migratory pattern and subsequent distribution of the GFP-labeled cells in the developing somatosensory cortex of control and BCNU-treated animals. To this aim, we investigated the expression of a panel of developmental marker genes which identified radial glia cells (Pax6), intermediate precursors cells (Tbr2), and postmitotic neurons destined to infragranular (Tbr1) or supragranular layers (Satb2). The VZ of BCNU-treated rats appeared disorganized since E18 and at E21 the embryos showed an altered migratory pattern: migration of superficial layers appeared delayed, with a number of migrating cells in the intermediate zone and some neurons destined to superficial layers arrested in the VZ, thus forming periventricular heterotopia. Moreover, neurons that reached their correct position did not extend their axons through the corpus callosum in the contralateral hemisphere as in the control, but toward the ipsilateral cingulated cortex. Our analysis sheds light on how a malformed cortex develops after a temporally discrete environmental insult.
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Affiliation(s)
- Ramona Frida Moroni
- Unit of Clinical Epileptology and Experimental Neurophysiology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
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