Immunodetection analysis of muscular dystrophies in Mexico.

INTRODUCTION: The muscular dystrophies (MDs) result from perturbations in the myofibers. These alterations are induced in part by mechanical stress due to membrane cell fragility, disturbances in mechanotransduction pathways, muscle cell physiology, and metabolism. METHODS: We analyzed 290 biopsies of patients with a clinical diagnosis of muscular dystrophy. Using immunofluorescence staining, we searched for primary and secondary deficiencies of 12 different proteins, including membrane, costamere, cytoskeletal, and nuclear proteins. In addition, we analyzed calpain-3 by immunoblot. RESULTS: We identified 212 patients with varying degrees of protein deficiencies, including dystrophin, sarcoglycans, dysferlin, caveolin-3, calpain-3, emerin, and merosin. Moreover, 78 biopsies showed normal expression of all investigated muscle proteins. The frequency rates of protein deficiencies were as follows: 52.36% dystrophinopathies; 18.40% dysferlinopathies; 14.15% sarcoglycanopathies; 11.32% calpainopathies; 1.89% merosinopathies; 1.42% caveolinopathies; and 0.47% emerinopathies. Deficiencies in lamin A/C and telethonin were not detected. CONCLUSION: We have described the frequency of common muscular dystrophies in Mexico.

Peripheral blood transcriptome profiling enables monitoring disease progression in dystrophic mice and patients.

DMD is a rare disorder characterized by progressive muscle degeneration and premature death. Therapy development is delayed by difficulties to monitor efficacy non-invasively in clinical trials. In this study, we used RNA-sequencing to describe the pathophysiological changes in skeletal muscle of 3 dystrophic mouse models. We show how dystrophic changes in muscle are reflected in blood by analyzing paired muscle and blood samples. Analysis of repeated blood measurements followed the dystrophic signature at five equally spaced time points over a period of seven months. Treatment with two antisense drugs harboring different levels of dystrophin recovery identified genes associated with safety and efficacy. Evaluation of the blood gene expression in a cohort of DMD patients enabled the comparison between preclinical models and patients, and the identification of genes associated with physical performance, treatment with corticosteroids and body measures. The presented results provide evidence that blood RNA-sequencing can serve as a tool to evaluate disease progression in dystrophic mice and patients, as well as to monitor response to (dystrophin-restoring) therapies in preclinical drug development and in clinical trials.

[Diagnosis and treatment with steroids for patients with Duchenne muscular dystrophy: experience and recommendations for Mexico. Administración del Patrimonio de la Beneficencia Pública. Asociación de Distrofia Muscular de Occidente]. / Diagnóstico y tratamiento con esteroides de pacientes con distrofia muscular de Duchenne: experiencia y recomendaciones para México.

Duchenne muscular dystrophy is a severe, debilitating and progressive disease that affects 1 in 3,500 live male births in the world. The diagnosis should be confirmed by genetic testing to identify the mutation in the DMD gene or muscle biopsy and immunostaining to demonstrate the absence of dystrophin. Although up to now continues to be an incurable disease, this does not mean it has no treatment. Treatment should be multidisciplinary, looking for the functionality of the patient and avoiding or correcting complications, mainly cardio-respiratory and skeletal. Many proposals have been evaluated and implemented with the aim of improving the quality of life for these patients. The long-term steroids have shown significant benefits, such as prolonging ambulation, reduce the need for spinal surgery, improve cardiorespiratory function and increase survival and the quality of life. This document presents the recommendations based on the experience of the working group and experts worldwide on the diagnosis and treatment with steroids for patients with Duchenne muscular dystrophy.

TITLE: Diagnostico y tratamiento con esteroides de pacientes con distrofia muscular de Duchenne: experiencia y recomendaciones para Mexico.La distrofia muscular de Duchenne es una enfermedad grave, incapacitante y progresiva que afecta a 1 de cada 3.500 recien nacidos varones alrededor del mundo. El diagnostico debera confirmarse mediante pruebas geneticas para identificar la mutacion en el gen DMD, o bien por biopsia muscular e inmunotincion para demostrar la ausencia de distrofina. Aunque actualmente continua siendo una enfermedad incurable, no significa que no tenga tratamiento. Este debe ser multidisciplinario, buscando la funcionalidad del paciente y evitando o corrigiendo las complicaciones, principalmente cardiorrespiratorias y esqueleticas. Se han evaluado e implementado multiples propuestas con la finalidad de mejorar la calidad de vida en estos pacientes. Los esteroides a largo plazo han demostrado importantes beneficios para los pacientes, prolongan la deambulacion, reducen la necesidad de cirugia de columna, mejoran la funcion cardiorrespiratoria, y aumentan la supervivencia y la calidad de vida. En este documento se presentan las recomendaciones con base en la experiencia del grupo de trabajo y de los expertos de ambito mundial sobre el diagnostico y el tratamiento con esteroides para los pacientes con distrofia muscular de Duchenne.

[Genotype-phenotype discordance in a Duchenne muscular dystrophy patient due to a novel mutation: insights into the shock absorber function of dystrophin]. / Discordancia genotipo-fenotipo en un paciente con distrofia muscular de Duchenne por una nueva mutación: hipótesis de la función de amortiguación de la distrofina.

INTRODUCTION: Duchenne muscular dystrophy (DMD) is a genomic disorder characterized by progressive muscle wasting and weakness due to the absence or abnormal function of dystrophin; a protein that protects muscle cells from mechanical induced stress during contraction. Mutations in the DMD gene, may lead to different clinical phenotypes, collectively known as dystrophinopathies, of which DMD has the earliest onset and most severe progression. CASE REPORT: We report a novel deletion of exons 24-41, predicted to maintain the reading frame and expected to result in a mild phenotype. Conversely, the patient has a severe DMD phenotype. CONCLUSIONS: Our report supports the hypothesis that disruption of the gamma-actin-binding site located in the central rod domain plays a crucial role in the shock absorber function of dystrophin in muscle cells. Description of pathogenic variants in the DMD gene and the resulting phenotypes has important implications on the designing of molecular therapeutic approaches for DMD.

[Improvements in the diagnosis of dystrophinopathies: what have we learnt in these last 20 years?]. / Mejoras en el diagnostico de distrofinopatias: que hemos aprendido despues de 20 anos?

INTRODUCTION. Dystrophinopathies are X-linked genetic disorders caused by mutations in the DMD gene. Genetic tests are of utmost importance for management and genetic counseling of these diseases. However, the complexity of the DMD gene is a challenge for diagnosis. AIM. To describe recent advances in the diagnosis of dystrophinopathies, after 20 years since the firsts molecular assays for genetic screening for these diseases. DEVELOPMENT. Currently, a variety of strategies such as automated mutation detection, cell-based methods and high throughput haplotyping have been developed to facilitate diagnosis of dystrophinopathies, carrier detection, prenatal and preimplantation diagnosis. CONCLUSION. New technologies have improved early detection and optimal management of dystrophinopathies and have established the basis for future molecular medicine. The most significant advances in dystrophinopathy diagnosis are reviewed herein.

Diagnóstico y tratamiento con esteroides de pacientes con distrofia muscular de Duchenne: experiencia y recomendaciones para México / Diagnosis and treatment with steroids for patients with Duchenne muscular dystrophy: experience and recommendations for Mexico

La distrofia muscular de Duchenne es una enfermedad grave, incapacitante y progresiva que afecta a 1 de cada 3.500 recién nacidos varones alrededor del mundo. El diagnóstico deberá confirmarse mediante pruebas genéticas para identificar la mutación en el gen DMD, o bien por biopsia muscular e inmunotinción para demostrar la ausencia de distrofina. Aunque actualmente continúa siendo una enfermedad incurable, no significa que no tenga tratamiento. Éste debe ser multidisciplinario, buscando la funcionalidad del paciente y evitando o corrigiendo las complicaciones, principalmente cardiorrespiratorias y esqueléticas. Se han evaluado e implementado múltiples propuestas con la finalidad de mejorar la calidad de vida en estos pacientes. Los esteroides a largo plazo han demostrado importantes beneficios para los pacientes, prolongan la deambulación, reducen la necesidad de cirugía de columna, mejoran la función cardiorrespiratoria, y aumentan la supervivencia y la calidad de vida. En este documento se presentan las recomendaciones con base en la experiencia del grupo de trabajo y de los expertos de ámbito mundial sobre el diagnóstico y el tratamiento con esteroides para los pacientes con distrofia muscular de Duchenne (AU)

Duchenne muscular dystrophy is a severe, debilitating and progressive disease that affects 1 in 3,500 live male births in the world. The diagnosis should be confirmed by genetic testing to identify the mutation in the DMD gene or muscle biopsy and immunostaining to demonstrate the absence of dystrophin. Although up to now continues to be an incurable disease, this does not mean it has no treatment. Treatment should be multidisciplinary, looking for the functionality of the patient and avoiding or correcting complications, mainly cardio-respiratory and skeletal. Many proposals have been evaluated and implemented with the aim of improving the quality of life for these patients. The longterm steroids have shown significant benefits, such as prolonging ambulation, reduce the need for spinal surgery, improve cardiorespiratory function and increase survival and the quality of life. This document presents the recommendations based on the experience of the working group and experts worldwide on the diagnosis and treatment with steroids for patients with Duchenne muscular dystrophy (AU)

Discordancia genotipo-fenotipo en un paciente con distrofia muscular de Duchenne por una nueva mutación: hipótesis de la función de amortiguación de la distrofina / Genotype-phenotype discordance in a Duchenne muscular dystrophy patient due to a novel mutation: insights into the shock absorber function of dystrophin

Introducción. La distrofia muscular de Duchenne (DMD) es un trastorno caracterizado por atrofia muscular progresiva y debilidad, debido a la ausencia o alteración de la función de la distrofina, una proteína que protege a las células del músculo de la tensión mecánica inducida durante la contracción. Las mutaciones en el gen DMD pueden dar lugar a diferentes fenotipos clínicos, conocidos colectivamente como distrofinopatías, de los cuales la DMD es el más grave. Caso clínico. Se presenta una deleción nueva de los exones 24-41, que no interrumpe el marco de lectura y se espera que origine un fenotipo leve. Por el contrario, el paciente tiene un fenotipo DMD grave. Conclusiones. Nuestra comunicación apoya la hipótesis de que la interrupción del sitio de unión a gamma-actina situado en el dominio cilíndrico central desempeña un papel crucial en la función de amortiguador de distrofina en las células musculares. La descripción de las variantes patogénicas en el gen DMD y los fenotipos resultantes tienen importantes implicaciones en el diseño de estrategias terapéuticas moleculares para la DMD (AU)

Introduction. Duchenne muscular dystrophy (DMD) is a genomic disorder characterized by progressive muscle wasting and weakness due to the absence or abnormal function of dystrophin; a protein that protects muscle cells from mechanical induced stress during contraction. Mutations in the DMD gene, may lead to different clinical phenotypes, collectively known as dystrophinopathies, of which DMD has the earliest onset and most severe progression. Case report. We report a novel deletion of exons 24-41, predicted to maintain the reading frame and expected to result in a mild phenotype. Conversely, the patient has a severe DMD phenotype. Conclusions. Our report supports the hypothesis that disruption of the gamma-actin-binding site located in the central rod domain plays a crucial role in the shock absorber function of dystrophin in muscle cells. Description of pathogenic variants in the DMD gene and the resulting phenotypes has important implications on the designing of molecular therapeutic approaches for DMD (AU)

Mejoras en el diagnóstico de distrofinopatías: ¿qué hemos aprendido después de 20 años? / Improvements in the diagnosis of dystrophinopathies: what have we learnt in these last 20 years?

Introducción. Las distrofinopatías son trastornos genéticos ligados al cromosoma X causados por mutaciones en el gen DMD. Las pruebas genéticas son de suma importancia para la gestión y el asesoramiento genético de estas enfermedades. Sin embargo, la complejidad del gen DMD es un desafío para el diagnóstico. Objetivo. Describir los avances recientes en el diagnóstico de distrofinopatías, después de 20 años de los primeros ensayos moleculares para la detección genética de estas enfermedades. Desarrollo. En la actualidad, se han desarrollado una variedad de estrategias, como la detección de mutaciones automatizada, los métodos basados en células y la haplotipificación de alto rendimiento, para facilitar el diagnóstico de distrofinopatías, la detección de portadoras, el diagnóstico prenatal y preimplantacional. Conclusión. Las nuevas tecnologías han mejorado la detección temprana y el manejo óptimo de distrofinopatías, y han establecido la base para la medicina molecular en el futuro. Los avances más importantes en el diagnóstico de distrofinopatías se revisan en este documento (AU)

Introduction. Dystrophinopathies are X-linked genetic disorders caused by mutations in the DMD gene. Genetic tests are of utmost importance for management and genetic counseling of these diseases. However, the complexity of the DMD gene is a challenge for diagnosis. Aim. To describe recent advances in the diagnosis of dystrophinopathies, after 20 years since the firsts molecular assays for genetic screening for these diseases. Development. Currently, a variety of strategies such as automated mutation detection, cell-based methods and high throughput haplotyping have been developed to facilitate diagnosis of dystrophinopathies, carrier detection, prenatal and preimplantation diagnosis. Conclusion. New technologies have improved early detection and optimal management of dystrophinopathies and have established the basis for future molecular medicine. The most significant advances in dystrophinopathy diagnosis are reviewed herein. (AU)