ABSTRACT
Abstract Hereditary motor and sensory neuropathy, also known as Charcot-Marie-Tooth disease (CMT), traditionally refers to a group of genetic disorders in which neuropathy is the main or sole feature. Its prevalence varies according to different populations studied, with an estimate between 1:2,500 to 1:10,000. Since the identification of PMP22 gene duplication on chromosome 17 by Vance et al., in 1989, more than 100 genes have been related to this group of disorders, and we have seen advances in the care of patients, with identification of associated conditions and better supportive treatments, including clinical and surgical interventions. Also, with discoveries in the field of genetics, including RNA interference and gene editing techniques, new treatment perspectives begin to emerge. In the present work, we report the most import landmarks regarding CMT research in Brazil and provide a comprehensive review on topics such as frequency of different genes associated with CMT in our population, prevalence of pain, impact on pregnancy, respiratory features, and development of new therapies.
Resumo A neuropatia sensitivo-motora hereditária, também conhecida como doença de Charcot-Marie-Tooth (CMT), tradicionalmente se refere a um grupo de doenças genéticas em que a neuropatia é a principal ou única manifestação. Sua prevalência varia de acordo com as diferentes populações estudadas, com estimativa entre 1:2.500 a 1:10.000. Desde a identificação da duplicação do gene PMP22 no cromossomo 17, por Vance et al., em 1989, mais de 100 genes foram relacionados a esse grupo de doenças e temos visto avanços no atendimento aos pacientes, com identificação de condições associadas e melhores tratamentos de suporte, incluindo intervenções clínicas e cirúrgicas. Além disso, com as descobertas no campo da genética, incluindo técnicas de interferência de RNA e de edição genética, novas perspectivas de tratamento começaram a surgir. No presente trabalho, relatamos os marcos mais importantes sobre a pesquisa de CMT no Brasil e fornecemos uma revisão abrangente sobre tópicos como frequência de diferentes genes associados à CMT em nossa população, prevalência de dor, impacto na gravidez, alterações respiratórias e desenvolvimento de novas terapias.
ABSTRACT
Abstract Background: Charcot-Marie-Tooth disease type 2Q (CMT2Q) is a rare disorder (< 1/1,000,000 individuals worldwide) linked to chromosome 10p14 in the DHTKD1 gene. This phenotype is characterized by an adolescent or adulthood-onset, slowly progressive distal muscle weakness and symmetrical atrophy associated with reduced or absent deep tendon reflexes. Currently, only two familiar cases from China have been reported: one familiar case of eight individuals affected by isolated DHTKD1 gene mutation and one familiar case of two individuals affected by DHTKD1 gene mutation and GJB1 gene mutation. Case report: We present the case of a 10-year-old male patient with obesity, frequent falls, swollen legs and thighs, and pain in the lower and upper limbs. We performed the clinical evaluation and a clinical targeted exome test, which reported mutations on DHTKD1 y NTRK2 genes. Conclusions: Due to scientific and technological advances, genetic dysfunctions that can cause different diseases have been identified with greater sensitivity. Globally, this is the eleventh case reported of DHTKD1 gene mutation linked to CMT2Q. Moreover, this is the first case related to NTRK2 gene mutation (linked to obesity, hyperphagia, and delayed development). The patient showed an atypical CMT2Q phenotype additional to obesity. Therefore, we propose to study metabolic disorders linked to hereditary peripheral neuropathies.
Resumen Introducción: La enfermedad de Charcot-Marie-Tooth tipo 2Q (CMT2Q) es una alteración poco frecuente (< 1/1,000,000 habitantes en todo el mundo) condicionada por mutaciones en el gen DHTKD1, localizado en el cromosoma 10p14. El padecimiento inicia en la adolescencia o la edad adulta de manera lenta y progresiva, con debilidad muscular y atrofia distal simétrica, y afecta predominantemente las extremidades inferiores y los reflejos tendinosos profundos, que se encuentran reducidos o ausentes. Solo se ha reportado un caso familiar de ocho personas afectadas con la mutación aislada en el gen DHTKD1 y un caso familiar de dos personas afectadas con mutaciones en los genes DHTKD1 y GJB1, ambas familias de China. Caso clínico: Se presenta el caso de un paciente de sexo masculino de 10 años y 11 meses de edad con obesidad, caídas frecuentes, edema de miembros pélvicos y dolor en las extremidades inferiores y superiores. Se realizaron valoración clínica y estudio genético molecular de exoma dirigido, el cual reportó mutaciones en los genes DHTKD1 y NTRK2. Conclusiones: Gracias al avance científico y tecnológico se han podido identificar con mayor precisión las alteraciones genéticas causantes de diferentes enfermedades. Este es el undécimo caso reportado en el mundo de una mutación en el gen DHTKD1 asociada con la enfermedad de CMT2Q. También es el primer caso relacionado con una mutación del gen NTRK2 (asociada con obesidad, hiperfagia y retraso en el desarrollo). El paciente presentó un cuadro clínico atípico de enfermedad de CMT2Q agregado a obesidad. Por ello, se sugiere estudiar a fondo la conexión entre trastornos metabólicos y neuropatías periféricas hereditarias.
ABSTRACT
ABSTRACT The hereditary neuropathy with liability to pressure palsies (HNPP) is an autossomal dominant disorder manifesting recurrent mononeuropathies. Objective Evaluate its clinical and nerve conduction studies (NCS) characteristics, searching for diagnostic particularities. Method We reviewed the neurological manifestations of 39 and the NCS of 33 patients. Results Family history was absent in 16/39 (41%). The onset complaints were weakness in 24, pain in 6, sensory deficit in 5 and paresthesias in 4. Pain was seen in 3 other patients. The following neuropathy patterns were found: multiple mononeuropathy (26), mononeuropathy (7), chronic sensorimotor polyneuropathy (4), chronic sensory polyneuropathy (1) and unilateral brachial plexopathy (1). NCS showed a sensorimotor neuropathy with focal conduction slowing in 31, two had mononeuropathy and another brachial plexopathy. Conclusion HNPP presentation is variable and may include pain. The most frequent pattern is of an asymmetrical sensory and motor neuropathy with focal slowing at specific topographies on NCS.
RESUMO A neuropatia hereditária com susceptibilidade à pressão (HNPP) é uma doença autossômica dominante que manifesta mononeuropatias recorrentes. Objetivo Avaliar as características clínicas e os estudos da condução nervosa (ECN) procurando particularidades diagnósticas. Método Revisamos as características clínicas de 39 e os ECN de 33 pacientes. Resultados História familiar ausente em 16/39 (41%). As manifestações iniciais foram: fraqueza em 24, dor em 6, déficit sensitivo em 5 e parestesias em 4. Dor foi referida por outros 3 pacientes. Os seguintes padrões de neuropatia foram observados: mononeuropatia múltipla (26), mononeuropatia (6), polineuropatia sensitivo-motora (4), polineuropatia sensitiva (1) e plexopatia braquial unilateral (1). Os ECN mostraram uma neuropatia sensitivo-motora com redução focal da velocidade de condução em 31, dois tinham mononeuropatia e outro plexopatia braquial. Conclusão A apresentação da HNPP é variável e pode incluir dor. O padrão mais frequente é o de uma neuropatia sensitivo-motora assimétrica com alentecimentos focais da condução em topografias específicas nos ECN.
Subject(s)
Humans , Male , Female , Child, Preschool , Child , Adolescent , Adult , Middle Aged , Aged , Young Adult , Chromosomes, Human, Pair 17/genetics , Gene Deletion , Peripheral Nervous System Diseases/physiopathology , Neural Conduction/physiology , Paralysis , Paresthesia/etiology , Pressure , Sensation Disorders/etiology , Peripheral Nervous System Diseases/genetics , Neuralgia/etiologyABSTRACT
La enfermedad de Charcot-Marie-Tooth es una afección degenerativa del sistema nervioso periférico, que presenta gran heterogeneidad genética y clínica. La presentación con patrón autosómico dominante, conocida en algunas clasificaciones como de tipo 1, es la más frecuente; asimismo, la confección del árbol genealógico resulta ser el instrumento de mayor importancia para conocer el tipo de herencia. A tales efectos, se describen 2 casos clínicos pertenecientes a una familia con 35 miembros afectados por este trastorno neurológico, atendidos en el Centro Provincial de Genética Médica de Santiago de Cuba.
Charcot-Marie-Tooth disease is a degenerative affection of the peripheral nervous system that presents great genetic and clinic heterogeneity. The presentation with autosomal dominant pattern, well-known in some classifications as type I, is the most frequent; also, the making of the genealogical tree turns out to be the most important instrument to know the inheritance type. To such effects, 2 case reports belonging to a family with 35 members affected by this neurological dysfunction are described, assisted in the Provincial Center of Medical Genetics in Santiago de Cuba.
Subject(s)
Hereditary Sensory and Motor Neuropathy , Charcot-Marie-Tooth DiseaseABSTRACT
Background: Mutations of GDAP1 gene cause autosomal dominant and autosomal recessive Charcot-Marie-Tooth disease and more than 40 different mutations have been reported. The recessive Q163X mutation has been described in patients of Spanish ancestry, and a founder mutation in South American patients, originating in Spain has been demonstrated. Objective: We describe physical and histological features, and the molecular impact of mutation Q163X in a Colombian family. Methods: We report two female patients, daughters of consanguineous parents, with onset of symptoms within the first two years of life, developing severe functional impairment, without evidence of dysmorphic features, hoarseness or diaphragmatic paralysis. Electrophysiology tests showed a sensory and motor neuropathy with axonal pattern. Sequencing of GDAP1 gene was requested and the study identified a homozygous point mutation (c.487 C>T) in exon 4, resulting in a premature stop codon (p.Q163X). This result confirms the diagnosis of Charcot-Marie-Tooth disease, type 4A. Results: The patients were referred to Physical Medicine and Rehabilitation service, in order to be evaluated for ambulation assistance. They have been followed by Pulmonology service, for pulmonary function assessment and diaphragmatic paralysis evaluation. Genetic counseling was offered. The study of the genealogy of the patient, phenotypic features, and electrophysiological findings must be included as valuable tools in the clinical approach of the patient with Charcot-Marie-Tooth disease, in order to define a causative mutation. In patients of South American origin, the presence of GDAP1 gene mutations should be considered, especially the Q163X mutation, as the cause of CMT4A disease.
Antecedentes: Las mutaciones del gen GDAP1 son causantes de la enfermedad de Charcot Marie Tooth tanto autosómica dominante como recesiva, y se han reportado más de 40 mutaciones distintas. La mutación recesiva Q163X ha sido descrita en pacientes de ascendencia española y se ha demostrado una mutación fundadora originaria de España en pacientes de origen suramericano. Describimos las características físicas e histológicas y el impacto molecular de la mutación Q163X en una familia colombiana. Objetivo: Se describe el impacto de la mutación Q163X en las características físicas, histológicas y moleculares en una familia colombiana. Métodos: Se describe dos pacientes de sexo femenino, hijas de padres consanguíneos, quienes presentaron inicio de síntomas en los dos primeros años de vida, mostrando deterioro funcional severo, sin evidencia de dismorfía, disfonía o parálisis diafragmática. Los estudios de electrofisiología mostraron una neuropatía sensitiva y motora con patrón axonal. Se solicitó la secuenciación del gen GDAP1, y el estudio identificó una mutación homocigota puntual (c. 487 C>T) en el exón 4, causando un codón de parada prematuro (p. Q163X). Este resultado confirma el diagnóstico de Enfermedad de Charcot Marie Tooth, tipo 4A (recesiva, tipo axonal). Resultados: Las pacientes fueron remitidas al servicio de Fisiatría para evaluación de métodos de asistencia para deambulación. Ellas reciben seguimiento por el servicio de Neumología, quienes vigilan la función pulmonar y el desarrollo de parálisis diafragmática. Se brindó asesoramiento genético. La genealogía del paciente, las características fenotípicas y los hallazgos en los estudios electrofisiológicos son herramientas valiosas en el enfoque clínico del paciente con CMT, de forma que se pueda plantear una posible mutación causal. Se debe considerar la presencia de mutaciones en el gen GDAP1 en pacientes de origen suramericano, en especial la mutación Q163X, como causa de CMT4A.
Subject(s)
Adolescent , Child , Female , Humans , Charcot-Marie-Tooth Disease/genetics , Point Mutation , Colombia , Consanguinity , Charcot-Marie-Tooth Disease/pathology , Exons , Homozygote , Nerve Tissue Proteins , PedigreeABSTRACT
Introducción. La neuropatía hereditaria con susceptibilidad a la parálisis por presión (NHPP) es una enfermedad genética que afecta fundamentalmente al componente mielínico de los nervios periféricos. Este estudio pretende describir detalladamente tres casos no emparentados familiarmente, así como realizar una revisión bibliográfica actualizada sobre el tema. Casos clínicos. Pacientes de 23, 42 y 41 años estudiados por sospecha de neuropatía cubital (casos 1 y 2) y de síndrome del túnel carpiano bilateral (caso 3). Resultados. Los estudios neurofisiológicos mostraron la existencia de una polineuropatía sensitivo-motora de predominio desmielinizante y mayor intensidad en localizaciones susceptibles al atrapamiento nervioso. El estudio genético confirmó en todos ellos la existencia de una deleción a nivel del gen PMP22 (cromosoma 17p11.2). Conclusiones. Esta neuropatía hereditaria puede simular una simple neuropatía compresiva, estando por ello infradiagnosticada. Una anamnesis completa, así como un riguroso estudio neurofisiológico son fundamentales para una orientación diagnóstica adecuada.
Introduction. Hereditary neuropathy with liability to pressure palsy (HNPP) is a genetic disease that primarily affects the myelin of peripheral nerves. This study aims to describe in detail three cases with no familiar blood-ties and do an updated literature review on the topic. Clinical cases. 23, 42 and 41 years old patients studied for suspected ulnar neuropathy (cases 1 and 2) and bilateral carpal tunnel (case 3) syndrome. Results. The electromyographic examination revealed the existence of a sensory-motor demyelinating polyneuropathy of greater intensity in locations susceptible to nerve entrapment. The genetic study confirmed in all patients the existence of a deletion at the level of PMP22 gene (chromosome 17p11.2). Conclusions. This hereditary neuropathy can simulate a simple compressive neuropathy. Therefore it is underdiagnosed. A thorough anamnesis and a rigorous neurophysiological study are essential in a proper diagnostic orientation.
ABSTRACT
In 2002, Spring et al reported a family with an autosomal dominant form of hereditary sensory neuropathy; patients also presented adult onset of gastroesophageal reflux and cough. Since then, no further families have been described. Objective: To study a new Portuguese family with these characteristics. Method: To describe the clinical and neurophysiologic characteristics of one family with features of sensory neuropathy associated with cough and gastroesophageal erflux. Results: Three of five siblings presented a similar history of paroxysmal cough (5th decade). About a decade later they experienced numbness and paraesthesia in the feets and in all cases there was evidence of an axonal sensory neuropathy. A history of gastroesophageal reflux of variable severity and age of onset was also present. Discussion: Molecular genetic studies have demonstrated genetic heterogeneity between the hereditary sensory neuropathy type 1 subtypes. The identification of these families is of major importance because further work is required to identify the underlying genetic defect. .
Em 2002, Spring et al descreveram uma família com uma combinação de polineuropatia sensitiva hereditária, doença do refluxo gastroesofágico e tosse paroxística. Desde então não foram descritos outros casos. Objectivo: Estudar uma nova família portuguesa com essas características. Método: Caracterização clínica e neurofisiológica de uma família com a referida combinação de patologias. Resultados: Três, de cinco irmãos, apresentam uma história semelhante de tosse paroxística com início na 5a década. Cerca de uma década mais tarde iniciam quadro de parestesias em ambos os pés, com evidência de neuropatia sensitiva axonal. Todos os casos apresentam também uma história de doença do refluxo gastroesofágico de gravidade variável. Discussão: Nos últimos anos, os estudos de genética molecular permitiram evidenciar a heterogeneidade genética dos vários subtipos de polineuropatia sensitiva hereditária tipo 1. A identificação das famílias afectadas reveste-se de grande importância, nomeadamente na tentativa de caracterização da alteração genética deste subtipo. .
Subject(s)
Aged , Aged, 80 and over , Female , Humans , Male , Cough/etiology , Gastroesophageal Reflux/diagnosis , Hereditary Sensory and Autonomic Neuropathies/diagnosis , Age of Onset , Cough/genetics , Cough/physiopathology , Gastroesophageal Reflux/genetics , Gastroesophageal Reflux/physiopathology , Hereditary Sensory and Autonomic Neuropathies/genetics , Hereditary Sensory and Autonomic Neuropathies/physiopathology , Mutation , Neural Conduction , Pedigree , PortugalABSTRACT
Charcot-Marie-Tooth (CMT) disease is a hereditary neuropathy of motor and sensory impairment with distal predominance. Atrophy and weakness of lower limbs are the first signs of the disease. It can be classified, with the aid of electromyography and nerve conduction studies, as demyelinating (CMT1) or axonal (CMT2). OBJECTIVE: Clinical and neurophysiological investigation of a large multigenerational family with CMT2 with autosomal dominant mode of transmission. METHOD: Fifty individuals were evaluated and neurophysiological studies performed in 22 patients. RESULTS: Thirty individuals had clinical signs of motor-sensory neuropathy. Babinski sign was present in 14 individuals. Neurophysiological study showed motor-sensory axonal polyneuropathy. CONCLUSION: The clinical and neurophysiological characteristics of this family does not differ from those observed with other forms of CMT, except for the high prevalence of Babinski sign.
A doença de Charcot-Marie-Tooth (CMT) é uma neuropatia hereditária de acometimento sensitivo e motor de predomínio distal. Atrofia e fraqueza em membros inferiores são os primeiros sinais da doença. Pode ser classificada, com auxílio da eletroneuromiografia, em desmielinizante (CMT1) ou axonal (CMT2). OBJETIVO: Investigação clínica e neurofisiológica de família com portadores de CMT2 de herança dominante. MÉTODO: Foi feita avaliação neurológica de 50 indivíduos e eletroneuromiografia em 22 pacientes. RESULTADOS: Trinta indivíduos tinham sinais clínicos de neuropatia sensitivo-motora. Sinal de Babinski estava presente em 14 indivíduos. A eletroneuromiografia demonstrou polineuropatia axonal sensitiva e motora. CONCLUSÃO: As características clínicas e neurofisiológicas desta família não se diferem das observadas em outras formas de CMT, exceto pela alta prevalência de sinal de Babinski.
Subject(s)
Adolescent , Adult , Aged , Child , Female , Humans , Male , Middle Aged , Charcot-Marie-Tooth Disease/physiopathology , Pyramidal Tracts/physiopathology , Charcot-Marie-Tooth Disease/genetics , Electromyography/methods , Genetic Linkage/genetics , Pedigree , PhenotypeABSTRACT
Os autores apresentam dois irmãos com diagnóstico de analgesia congênita, com suas características clínicas e evolução. Essa doença é rara, apresenta alta morbidade e gera complicações osteoarticulares de difícil solução. O objetivo dos autores foi ressaltar a importância do diagnóstico tanto para o tratamento de suas afecções secundárias, quanto para seu aspecto jurídico.
The authors present two brothers with congenital pain insensitivity, with their clinical characteristics and evolution. This disease is rare, has high morbidity and originates complex osteoarticular complications. The aim of the authors was to emphasize the value of the diagnosis for a better treatment and to avoid legal problems to the parents.