Thesis (Ph. D.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains xii, 156 p. : ill. (some col.). Includes abstract. Includes bibliographical references.

A doença de Charcot-Marie-Tooth (CMT) caracteriza-se por comprometimento dos nervos periféricos de predomínio distal, tendo curso clínico variável. Observa-se quadro de evolução lenta de atrofia e fraqueza distal em membros inferiores, seguidos por diminuição da sensibilidade. Os reflexos estão em geral abolidos, mas podem estar exaltados e acompanhados de sinal de Babinski. É frequente o encontro de atrofia do terço distal das pernas, de pes cavos e de deformidades em artelhos. A doença de CMT pode ser classificada, com o auxílio da eletroneuromiografia, em desmielinizante (CMT1) ou axonal (CMT2). A CMT1 possui velocidade de condução motora do nervo mediano < 38 m/s e a CMT2 > 38m/s. A CMT1 é de herança autossômica dominante, e a CMT2 pode ser de herança dominante ou recessiva. A CMT2 é geneticamente heterogênea e conhecem-se até o momento 13 loci associados a essa condição, com nove genes identificados. O objetivo deste estudo é investigar do ponto de vista clínico, neurofisiológico e genético uma família com muitos portadores de CMT2. A família multigeneracional que apresenta CMT2 é procedente de Tobias Barreto, SE. Foi feita avaliação neurológica de 50 indivíduos e eletroneuromiografia em 22 pacientes. Com dados da avaliação clínica e eletroneuromiográfica foi aplicado o escore que avalia a gravidade da doença, o CMTNS. Para o estudo genético, foram coletadas 42 amostras de sangue de indivíduos afetados e de familiares não afetados. Entre os 50 indivíduos avaliados, 30 tinham sinais clínicos de neuropatia sensitivo-motora de predomínio distal. Paresia dos músculos distais foram os sinais clínicos mais precoces. Redução da sensibilidade superficial e profunda foi detectada nos segmentos distais. O sinal de Babinski estava presente em 14 indivíduos. A eletroneuromiografia demonstrou alterações compatíveis com polineuropatia axonal sensitiva e motora. O estudo genético demonstrou que, nesta família, CMT2 não está ligada a nenhum dos loci já conhecidos para esta condição, más o lócus do gene responsável não foi identificado até o momento. Em conclusão, as características clínicas e neurofisiológicas dessa família não diferem significativamente das observadas em outras formas de CMT, exceto pela alta prevalência de sinal de Babinski, e nossos resultados indicam a existência de um novo locus para CMT2 / Charcot-Marie-Tooth (CMT) disease is characterized by predominantly distal peripheral neuropathy with variable clinical course. Initial presentation is of a slowly progressive distal atrophy and weakness in lower limbs, followed by sensory compromise. Reflexes are usually abolished, but might be brisk and accompanied by Babinski sign. It is frequent to find distal atrophy of lower limbs, pes cavus and toe deformities. Electromyography can recognize two patterns of CMT: demyelinating (CMT1), which has a conduction median nerve velocity < 38 m/s and axonal (CMT2), with velocity > 38m/s. CMT1 is inherited as an autosomal dominant trait, and CMT2 might be transmitted as an autosomal dominant or recessive. CMT is genetically heterogeneous, and, up to now, 13 loci have been recognized and nine genes identified. The aim of this study was to conduct an investigation of clinical, genetics and neurophysiological investigation of a multigenerational family with several individuals with CMT2 and to characterize phenotype, neurophysiological pattern and genetic basis of this condition. Fifty individuals were clinically evaluated and nerve conduction velocity studies and distal muscular activity in lower limbs using concentric needle were performed in 22 patients. A blood sample was collect from 42 individuals, in order to perform linkage analysis. Thirty, among the 50 evaluated individuals, had clinical signs of predominantely distal sensory motor neuropathy. Distal muscle paresis was an early clinical sign. Reduction of superficial and deep sensory was detected distally. Babinski sign was present in 14 affected individuals. Neurophysiological study was characteristic of axonal sensory-motor neuropathy. Linkage analysis demonstrated that in this family, CMT2 was not linked to any already known loci for this condition, but the responsible gene locus was not identified so far. In conclusion, clinical and neurophysiological characteristics of this family did not differ substantially from other forms of CMT, except by the high prevalence of Babinski sign. Our study also suggests the presence of a new locus for CMT2

A doença de Charcot-Marie-Tooth (CMT) é desordem hereditária do sistema nervoso periférico, caracterizada por fraqueza dos membros inferiores, atrofia muscular e perda sensitiva. CMTX é doença ligada ao cromossomo X a qual corresponde aproximadamente 10% das famílias com CMT, sendo a segunda causa mais frequente da doença, após a duplicação 17p11.2-p12. Neste estudo analisamos 66 pacientes com CMT, negativos para duplicação 17p, por método de DHPLC, confirmado por sequenciamento direto. Foram identificadas seis mutações, em que quatro destas não foram descritas. Desta maneira confirmou uma frequência de mutações em torno de 9% no gene da Cx32. Portanto, nesta pesquisa do gene da Cx32 com CMT demonstrou que em uma população brasileira teve um comportamento mutacional semelhante ao das demais populações estudadas. / The Charcot-Marie-Tooth (CMT) is inherited disorder of the peripheral nervous system characterized by weakness of the lower limbs, muscular atrophy and sensory loss. CMTX is X-linked disease which accounts for approximately 10% of families with CMT, the second most frequent cause of disease after duplication 17p11.2-p12. This study analyzed 66 patients with CMT, negative for duplication 17p, by method of DHPLC, confirmed by direct sequencing. We identified six mutations, four of which were not described. In this way confirmed a mutation frequency of around 9% in the Cx32 gene. Therefore, this research Cx32 gene with CMT showed that in a Brazilian population had a mutational behavior similar to that of other populations studied.

La maladie de Charcot-Marie-Tooth (CMT) est une pathologie neurologique affectant le système nerveux périphérique. Bien que décrite à la fin du XIXème siècle, la découverte d’une anomalie génétique n’a été identifiée chez ces patients que dans les années 1990 (duplication du gène PMP22). Depuis, de nombreux gènes ont été incriminés, et leur nombre ne cesse d’augmenter. Ainsi, cette multitude de gènes nous incite à rechercher des corrélations phénotype-génotype qui permettent d’orienter au mieux le diagnostic et la prise en charge de ces patients. Comme nous le montrons au travers de nos travaux, il est possible de s’appuyer sur des données cliniques, biologiques, électrophysiologiques (voire radiologiques) et histo-pathologiques (biopsie de nerf) pour orienter la recherche d’anomalies génétiques. Pour illustrer ceci, nous nous sommes appuyés sur l’exemple des mutations du gène INF2, gène récemment associé à la maladie de Charcot-Marie-Tooth. Dans ce cas précis, l’atteinte rénale, le profil électrophysiologique (forme « intermédiaire » de CMT) et surtout les données histo-pathologiques (la biopsie de nerf permettant de retrouver la présence d’expansions schwanniennes caractéristiques) sont évocatrices de la présence d’une anomalie portée par ce gène. D’autres exemples de corrélations génotype-phénotype sont apportés au travers d’observations. / Charcot-Marie-Tooth disease (CMT) is a neurological disorder of the peripheral nervous system. Even if it was described in the end of the nineteenth century, the first genetic abnormality (PMP22 duplication) was found only in the end of the twentieth century. Several other genes were found to be associated with this disease. This important number of potential genes leads us to find genotype-phenotype correlations in order to better and earlier diagnose these patients. As we can show it in our work, it is possible to use biological, electrophysiological (sometimes radiological) and pathological (nerve biopsy) in order to direct the genetic analysis towards the incriminated gene. To illustrate this, we have particularly study the INF2 gene, a gene recently associated with CMT. In this example, clinical (CMT phenotype and renal failure), electrophysiological (intermediate form of CMT), and pathological (supernumerary extensions of Schwann cells cytoplasm) features call to mind mutations in the INF2 gene. Other examples of genotype-phenotype correlations associated with various genes are reported in this manuscript.

No description available.

Entre as neuropatias periféricas hereditárias, a Doença de Charcot Marie Tooth (CMT) é a mais prevalente, sendo o Charcot Marie Tooth Lidado ao X tipo 1 (CMTX1) o segundo subtipo mais comum, causado por mutações no gene GJB1 e de herança ligada ao X. A sintomatologia de fraqueza, atrofia e alteração de sensibilidade progressiva, de padrão simétrico e distal é característica da CMT e, no CMTX1, o acometimento do sistema nervoso central pode estar associado ao quadro típico. Com relação à eletroneurofisiologia, há redução dos parâmetros de velocidade de condução nervosa, com prolongamento da latência de onda F. Não há terapias modificadoras do curso da doença, sendo importante acompanhamento multidiciplinar a fim de assistir as possíveis deformidades, dando mais conforto e otimização das atividades de vida diária dos pacientes. O objetivo do presente estudo é relatar casos diagnosticados como CMTX1 atendidos pelo ambulatório de Neurogenética do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (HCFMRP-USP) e comparar aos dados da literatura pertinente. Os critérios de inclusão foram idade no atendimento abaixo de 17 anos e 11 meses e confirmação do CMTX1 por exame genético molecular, com mutação em GJB1. Assim, foram encontradas quatro crianças, três do sexo feminino e uma do masculino, com idade variando de 3 a 17 anos, sendo que em dois deles foi observado atraso na marcha independente. Os sinais clínicos e eletroneuromiográficos observados foram concordantes com a literatura, exceto por não apresentarem sinais de acometimento do sistema norvoso central (SNC) associados. A presença de atraso na marcha e surgimento de casos precoces suscita a necessidade de protocolo adequado para crianças no primeiro e segundo anos de vida; 1. Anotar época de aparecimento e duração do movimento de levantar-se e postura ereta ou não do tronco ao se manter sentado. 2. Tipo do engatinhar. 3. Idade em meses no início de sentar e andar com e sem apoio. 4. Análise da funcionalidade manual, motricidade fina com auxílio de testes da especialidade em terapia ocupacional, desde os primeiros meses. 5. Tipo de marcha e época de início da marcha. 6. Reflexos fásicos - evolução - com atenção especial aos aquilianos, que são os mais precocemente acometidos. 7. Verificação de clônus de tornozelo, no sentido de detecção de sinais de espasticidade. Para crianças maiores de 3 anos de idade: 1. Início do uso de chinelo (capacidade de reter o chinelo nos pés - desenvolvimento da propriocepção). 2. Verificação do equilíbrio estático e dinâmico de acordo com Lefèvre (1972), nas faixas etárias de 3 a 7 anos. / Among the hereditary peripheral neuropathies, Charcot-Marie-Tooth disease (CMT) is the most prevalent, being the second most common the subtype CMTX1, caused by mutations in the GJB1 gene and producing a X-linked inheritance. The symptoms of symmetrical and distal weakness, atrophy and progressive sensory changes, are characteristics of the CMT and in the CMTX1 central nervous system involvement is often associated with the typical picture. With respect to eletroneurophysiology, there is reduction of nerve conduction velocity parameters, with extension of F wave latency. There is no modifier therapies of the course of the disease, being important, multidisciplinary monitoring to assist the possible deformities, giving more comfort and optimization of daily life activities of patients. The main objective of this study is to report cases diagnosed as CMTX1 by Neurogenetics Clinic of the Hospital of Clinics of the School of Medicine at Ribeirão Preto, São Paulo University (HCFMRPUSP) and to compare the data from the relevant literature. Inclusion criteria were age in attendance below 17 years and 11 months and CMTX1 confirmation by genetic testing, mutation GJB1. Four children were included, three female and a male, with age ranging from 3 to 17 years. Two of them presented late onset of independent walking. Clinical and eletroneuromiographics finds resulted similar to that observed in the literature, except for the absence of clinical signs of CNS involvement. The presence of delay for independent walking raises the need for proper protocol for children in the first and second years of life: 1. Time of onset (age) and duration of motion to lift from a horizontal position and upright posture of trunk to keep sitting. 2. Type of crawl. 3. Age in months earlier to sit and walk with and without support. 4. Analysis of manual functionality, fine motricity with specialty tests in occupational therapy, since the first few months age. 5. Type of gear when he or she begins to walk with support, and then, without support, the use of the heels. 6. Stretch Reflex - evolution - with special attention to the aquileus, that are the most affected early. 7. Ankle clonus checking, aimed to detecting signs of spasticity. For children after 3 years of age: 1. Initiation of the use of slippers (ability to retain the slippers on the feet - proprioception development). 2. Verification of static and dynamic balance according to Lefèvre (1972), in the age groups from 3 to 7 years.

Entre as neuropatias periféricas hereditárias, a Doença de Charcot Marie Tooth (CMT) é a mais prevalente, sendo o Charcot Marie Tooth Lidado ao X tipo 1 (CMTX1) o segundo subtipo mais comum, causado por mutações no gene GJB1 e de herança ligada ao X. A sintomatologia de fraqueza, atrofia e alteração de sensibilidade progressiva, de padrão simétrico e distal é característica da CMT e, no CMTX1, o acometimento do sistema nervoso central pode estar associado ao quadro típico. Com relação à eletroneurofisiologia, há redução dos parâmetros de velocidade de condução nervosa, com prolongamento da latência de onda F. Não há terapias modificadoras do curso da doença, sendo importante acompanhamento multidiciplinar a fim de assistir as possíveis deformidades, dando mais conforto e otimização das atividades de vida diária dos pacientes. O objetivo do presente estudo é relatar casos diagnosticados como CMTX1 atendidos pelo ambulatório de Neurogenética do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (HCFMRP-USP) e comparar aos dados da literatura pertinente. Os critérios de inclusão foram idade no atendimento abaixo de 17 anos e 11 meses e confirmação do CMTX1 por exame genético molecular, com mutação em GJB1. Assim, foram encontradas quatro crianças, três do sexo feminino e uma do masculino, com idade variando de 3 a 17 anos, sendo que em dois deles foi observado atraso na marcha independente. Os sinais clínicos e eletroneuromiográficos observados foram concordantes com a literatura, exceto por não apresentarem sinais de acometimento do sistema norvoso central (SNC) associados. A presença de atraso na marcha e surgimento de casos precoces suscita a necessidade de protocolo adequado para crianças no primeiro e segundo anos de vida; 1. Anotar época de aparecimento e duração do movimento de levantar-se e postura ereta ou não do tronco ao se manter sentado. 2. Tipo do engatinhar. 3. Idade em meses no início de sentar e andar com e sem apoio. 4. Análise da funcionalidade manual, motricidade fina com auxílio de testes da especialidade em terapia ocupacional, desde os primeiros meses. 5. Tipo de marcha e época de início da marcha. 6. Reflexos fásicos - evolução - com atenção especial aos aquilianos, que são os mais precocemente acometidos. 7. Verificação de clônus de tornozelo, no sentido de detecção de sinais de espasticidade. Para crianças maiores de 3 anos de idade: 1. Início do uso de chinelo (capacidade de reter o chinelo nos pés - desenvolvimento da propriocepção). 2. Verificação do equilíbrio estático e dinâmico de acordo com Lefèvre (1972), nas faixas etárias de 3 a 7 anos. / Among the hereditary peripheral neuropathies, Charcot-Marie-Tooth disease (CMT) is the most prevalent, being the second most common the subtype CMTX1, caused by mutations in the GJB1 gene and producing a X-linked inheritance. The symptoms of symmetrical and distal weakness, atrophy and progressive sensory changes, are characteristics of the CMT and in the CMTX1 central nervous system involvement is often associated with the typical picture. With respect to eletroneurophysiology, there is reduction of nerve conduction velocity parameters, with extension of F wave latency. There is no modifier therapies of the course of the disease, being important, multidisciplinary monitoring to assist the possible deformities, giving more comfort and optimization of daily life activities of patients. The main objective of this study is to report cases diagnosed as CMTX1 by Neurogenetics Clinic of the Hospital of Clinics of the School of Medicine at Ribeirão Preto, São Paulo University (HCFMRPUSP) and to compare the data from the relevant literature. Inclusion criteria were age in attendance below 17 years and 11 months and CMTX1 confirmation by genetic testing, mutation GJB1. Four children were included, three female and a male, with age ranging from 3 to 17 years. Two of them presented late onset of independent walking. Clinical and eletroneuromiographics finds resulted similar to that observed in the literature, except for the absence of clinical signs of CNS involvement. The presence of delay for independent walking raises the need for proper protocol for children in the first and second years of life: 1. Time of onset (age) and duration of motion to lift from a horizontal position and upright posture of trunk to keep sitting. 2. Type of crawl. 3. Age in months earlier to sit and walk with and without support. 4. Analysis of manual functionality, fine motricity with specialty tests in occupational therapy, since the first few months age. 5. Type of gear when he or she begins to walk with support, and then, without support, the use of the heels. 6. Stretch Reflex - evolution - with special attention to the aquileus, that are the most affected early. 7. Ankle clonus checking, aimed to detecting signs of spasticity. For children after 3 years of age: 1. Initiation of the use of slippers (ability to retain the slippers on the feet - proprioception development). 2. Verification of static and dynamic balance according to Lefèvre (1972), in the age groups from 3 to 7 years.

Thesis (Ph.D.)--University of Western Australia, 2006.

Bei den Charcot-Marie-Tooth (CMT) Neuropathien handelt es sich um erbliche Erkrankungen des peripheren Nervensystems, die progredient zu motorischen und sensorischen Defiziten führen und für die bislang keine kausalen Therapieoptionen existieren. In verschiedenen Studien konnte gezeigt werden, dass Entzündungsreaktionen, insbesondere durch Lymphozyten und Makrophagen vermittelt, eine bedeutende Rolle bei der Pathogenese dieser Erkrankung spielen. Neben neuronaler und axonaler Schädigung, sowie Demyelinisierung ist in untersuchten Myelin Mutanten auch eine erhöhte Anzahl an denervierten neuromuskulärer Endplatten zu erkennen. Eine genetische Blockade der Makrophagen-Aktivierung konnte in den Studien eine Verbesserung sämtlicher neuropathologischer Merkmale bei gleichzeitig reduzierter Makrophagenanzahl zeigen. Ob und welche Rolle Makrophagen bei der Denervation neuromuskulärer Endplatten spielen, blieb bislang ungeklärt. In dieser Studie konnte in allen untersuchten Myelin Mutanten im Vergleich zum Wildtyp eine Zunahme an neuromuskulären Synapsen beobachtet werden, die mit Makrophagen räumlich assoziiert waren. Daneben zeigten entsprechende Myelin Mutanten eine Zunahme denervierter und partiell denervierter Endplatten und zwar interessanterweise direkt proportional zur Anzahl an Synapsen in Assoziation mit Makrophagen. Das bedeutet, dass die Anzahl an Endplatten in Assoziation mit Makrophagen verhältnismäßig parallel zur Anzahl an denervierten Endplatten zunahm, während die Anzahl an Makrophagen im gesamten Muskel nahezu unverändert blieb. Dies deutet eine mögliche Rolle der räumlich mit Endplatten assoziierten Makrophagen an deren Denervation an. Dabei waren alle Synapsen in Assoziation mit Makrophagen innerviert und damit morphologisch intakt. Bei doppel-mutanten Mäusen mit genetischer Blockade der Makrophagen-Aktivierung waren die beschriebenen pathologischen Merkmale an der neuromuskulären Synapse deutlich reduziert bei gleichzeitig signifikanter Abnahme an Makrophagen in Assoziation mit Endplatten. Ähnliche pathologische Auffälligkeiten wie bei Myelin Mutanten fanden sich in geringerer Ausprägung auch im Wildtyp im Rahmen des Alterungsprozesses sowie auch bei Mäusen mit Defizienz des neurotrophen Faktors CNTF. Zusammenfassend deuten die Ergebnisse darauf hin, dass sowohl in der Pathogenese der CMT Neuropathie wie auch im Rahmen altersbedingter Neurodegeneration ein Makrophagen-vermittelter Schaden an der neuromuskulären Endplatte entsteht. Wesentliche Mediatoren scheinen hierbei das von Fibroblasten und vermutlich auch perisynaptischen Fibroblasten exprimierte CSF-1 zu sein, sowie MCP-1, das durch Schwann Zellen und möglicherweise auch von terminalen Schwann Zellen freigesetzt wird. Auch eine Defizienz des neurotrophen Faktors CNTF bewirkt zumindest in geringem Ausmaß eine Zunahme der pathologischen Merkmale Denervation und Makrophagen-Endplatten-Assoziation im Vergleich zum Wildtyp. Diese Ergebnisse erweitern insbesondere das Wissen um Pathomechanismen an der neuromuskulären Endplatte und eröffnen neue Möglichkeiten der Behandlung für CMT und weitere neuromuskuläre Erkrankungen. / Charcot-Marie-Tooth (CMT) neuropathies are a group of hereditary diseases of the peripheral nervous system that progressively lead to motor and sensory deficits and for which currently no causal therapeutic options exist. Various studies revealed that inflammatory reactions, especially mediated by lymphocytes and macrophages, play a significant role in the pathogenesis of this disease. In addition to demyelination, neuronal and axonal damage, an increased number of denervated neuromuscular junctions were detected in myelin mutant mice. In these studies, a genetic blockade of macrophage activation induced an improvement in all neuropathological features with a simultaneous reduction in the number of macrophages. Whether and which role macrophages play in the denervation of neuromuscular endplates remained unclear by now. In this presented study, an increase in neuromuscular synapses spatially associated with macrophages was observed in all investigated myelin mutant mice compared to wild type mice. In addition, corresponding myelin mutants showed an increase in denervated and partially denervated endplates directly proportional to the number of synapses associated with macrophages. This means that the number of endplates in association with macrophages increased relatively in parallel with the number of denervated endplates, while the number of macrophages remained nearly unchanged throughout the skeletal muscle. This suggests a possible pathogenetic role of spatially endplate-associated macrophages in their denervation. All synapses in association with macrophages were innervated and thus morphologically intact. In dual mutant mice with a genetic blockade of macrophage activation, the described pathological features at the neuromuscular junction were significantly reduced with concomitant significant decrease in macrophages associated with endplates. Similar pathological abnormalities as in myelin mutants were found to a lesser extent also in the wild type in the context of the aging process as well as in mice with deficiency of the neurotrophic factor CNTF. In summary, these results suggest that macrophage-related damage of neuromuscular junctions occurs in both the pathogenesis of CMT neuropathy and in the context of age-related neurodegeneration. Important mediators seem to be CSF-1 expressed by fibroblasts and probably also perisynaptic fibroblasts, as well as MCP-1, which is released by Schwann cells and possibly also by terminal Schwann cells. Furthermore, a deficiency of the neurotrophic factor CNTF causes, at least to a small extent, an increase in the pathological features of denervation and macrophage-endplate association compared to the wild-type. In particular, these findings expand knowledge of pathomechanisms at the neuromuscular endplate and open up new treatment options for CMT and other neuromuscular diseases.

Dynein is a motor protein complex that transports various types of intracellular cargos from the cell periphery towards the cell center. Dynein mutations are linked to several neurodegenerative diseases, including Charcot-Marie-Tooth disease (CMT). A mouse model of CMT was generated with a knock-in H304R dynein allele. This mutation at position 304 corresponds to the H306R mutation found in humans that can cause CMT. Here, a behavioral test was developed to study the onset and progression of CMT symptoms in these mice. In the tail suspension test, mice were suspended briefly by their tails and the posture of their hind limbs was scored. Wildtype mice spread their hind limbs outwards in a characteristic splayed posture, whereas heterozygous and homozygous mutants display abnormal phenotypes. In further investigation, the neuromuscular junctions of these mice were analyzed in order to understand the histological effects of the mutation and how the potential differences could result in the behavioral effects observed. The extent of neuromuscular junction innervation was examined along with the size and complexity of the neuromuscular junctions themselves through multiple criteria. This, when combined with the effects observed during the tail suspension behavioral test, seeks to establish the H304R mutant mouse as a successful model for CMT.