Distrofia muscular de Duchenne, una causa infrecuente de miocardiopatía dilatada / Duchenne muscular dystrophy, a rare cause of dilated cardiomyopathy

Neuromuscular diseases represent a rare cause of dilated myocardiopathy, among them Duchenne muscular dystrophy is the most common. Transthoracic echocardiography and cardiac magnetic resonance imaging can assess cardiac involvement early. The case of a patient diagnosed with Duchenne muscular dystrophy who develops cardiac involvement during cardiology follow-up is presented below.

Genetic analysis of a Chinese pedigree affected with Becker muscular dystrophy with myalgia as the main feature / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis of a Chinese pedigree affected with Becker muscular dystrophy (BMD) with myalgia as the main feature.@*METHODS@#Clinical data of the patients and results of auxiliary examinations were retrospectively analyzed. Multiplex ligation-dependent probe amplification and high-throughput sequencing were used to detect potential variants. Sanger sequencing was used to verify the results.@*RESULTS@#The clinical manifestations of the proband included myalgia and elevated serum creatine kinase, which is similar to another patient from the pedigree. Genetic testing revealed that the two patients both harbored hemizygous deletions of exons 10 to 29 of the DMD gene, for which the mother was a carrier. The same deletion was not found in his father. Based on the guidelines from American College of Medical Genetics and Genomics, the deletion was predicted to be pathogenic (PVS1+PM2+PP1).@*CONCLUSION@#Myalgia with elevated serum CK may be atypical clinical manifestations of BMD and may be associated with variants in the rod domain of the DMD gene. The deletion of exons 10 to 29 of the DMD gene probably underlay the BMD in this pedigree.

Carrier screening model for Duchenne muscular dystrophy for women of reproductive age based on a pre-pregnancy birth defect control platform / 中华医学遗传学杂志

OBJECTIVE@#To establish a screening model for females of reproductive age carrying Duchenne muscular dystrophy (DMD) variants based on a current community health examination platform.@*METHODS@#A total of 61 870 participants were recruited between October 2017 and October 2019. Serum creatine kinase (CK) was measured with a Roche Cobasc 701/702 using an enzymatic rate method. Genetic testing was offered to those with a CK level of ≥ 200 U/L. For carriers of DMD variants, genetic counseling and follow up were provided.@*RESULTS@#For the 61 870 females participating in the program, 1078 were found with raised serum CK (≥ 200 U/L), of which 618 (57.33%) accepted CK re-measurement after at least a two-week interval. One hundred and twenty cases were found with sustained serum CK elevation, of which 6 were confirmed to be definite DMD carriers regardless of family history. Genetic testing was provided to 33 females with a family history for DMD, and 13 were determined as definite carriers. An affected fetus was detected by prenatal diagnosis. After genetic counseling, the parents had opted induced abortion.@*CONCLUSION@#Large-scale DMD carrier screening through a three-step approach based on the current community health examination platform is both feasible and cost effective.

Study on newborn screening for Duchenne muscular dystrophy and diagnostic strategy / 中华医学遗传学杂志

OBJECTIVE@#To establish a newborn screening system for Duchenne muscular dystrophy (DMD) through assessment of MM isoenzyme of creatine kinase (CK-MM) activity.@*METHODS@#The CK-MM level was detected using dry blood spot filter paper from 10 252 male newborns. The results were grouped based on their gestational age, sampling time and intervals between the experiments. The threshold value for CK-MM necessitating genetic testing was determined. Next-generation sequencing (NGS) was carried out for those with a CK-MM value over the threshold, and the result was verified by multiplex ligation-dependent probe amplification (MLPA).@*RESULTS@#Based on the result of non-parametric rank sum test, the median CK-MM concentration has increased with the gestational age, and was inversely correlated with the age of the newborns among unaffected specimens. CK-MM on dry blood spot filter paper can be stable for 14 days at 2-8℃. Statistical analysis of CK-MM value of the 10 252 neonates suggested that the threshold may be set as 700 ng/mL. Exonic deletions were found in 2 confirmed cases, whose CK-MM level was greater than 2000 ng/mL.@*CONCLUSION@#Detection of CK-MM in dry blood spot filter paper has provided an effective method for newborn screening of DMD. This simple and inexpensive method can be used for large-scale screening, which is of great value to the early intervention and treatment of the disease.

Diagnosis of a patient with adjacent gene deletion syndrome with DMD complete deletion type of Duchenne muscular dystrophy / 中华医学遗传学杂志

OBJECTIVE@#To identify the etiology of a patient with severe symptoms of DMD and to trace its pathogenic gene, so as to provide a basis for genetic counseling and clinical intervention.@*METHODS@#Multiple ligation-dependent probe amplification (MLPA) technique was used to analyze exon deletion/repetitive variant of DMD gene, and further analysis was performed by chromosome G-banding, fluorescence in situ hybridization (FISH) and SNP array analysis.@*RESULTS@#The MLPA results of the proband showed that the exon 1-79 of DMD gene were deleted, the G-banding karyotype of blood sample was 46, XY, and the deletion of the short arm of X chromosome was found by FISH. SNP array results showed that 5.8Mb (29 628 158-35 434 714) deletion occurred in the Xp21.2p21.1 region of X chromosome, and the patient was diagnosed as the contiguous deletion syndrome involving the genes of IL1RAPL, MAGEB1-4, ROB, CXorf2, GM, AP3K7IP, FTHL1, DMD, FAM47A, TMEM47, and FAM47B.@*CONCLUSION@#The exact pathogenic site of this family is the deletion of 5.8 Mb (29 628 158-35 434 714) in the Xp21.2p21.1 region of X chromosome, which can be used for prenatal diagnosis. High resolution SNP array technique plays an important role in detecting potential chromosome abnormalities in patients.

Functional performance and muscular strength in symptomatic female carriers of Duchenne muscular dystrophy / Desempenho funcional e força muscular em portadoras sintomáticas de distrofia muscular de Duchenne

Abstract Duchenne muscular dystrophy (DMD) usually affects men. However, women are also affected in rare instances. Approximately 8% of female DMD carriers have muscle weakness and cardiomyopathy. The early identification of functional and motor impairments can support clinical decision making. Objective: To investigate the motor and functional impairments of 10 female patients with dystrophinopathy diagnosed with clinical, pathological, genetic and immunohistochemical studies. Methods: A descriptive study of a sample of symptomatic female carriers of DMD mutations. The studied variables were muscular strength and functional performance. Results: The prevalence was 10/118 (8.4%) symptomatic female carriers. Deletions were found in seven patients. The age of onset of symptoms in female carriers of DMD was quite variable. Pseudohypertrophy of calf muscles, muscular weakness, compensatory movements and longer timed performance on functional tasks were observed in most of the cases. Differently from males with DMD, seven female patients showed asymmetrical muscular weakness. The asymmetric presentation of muscle weakness was frequent and affected posture and functionality in some cases. The functional performance presents greater number of compensatory movements. Time of execution of activities was not a good biomarker of functionality for this population, because it does not change in the same proportion as the number of movement compensations. Conclusion: Clinical manifestation of asymmetrical muscle weakness and compensatory movements, or both can be found in female carriers of DMD mutations, which can adversely affect posture and functional performance of these patients.

Resumo A distrofia muscular de Duchenne (DMD) geralmente afeta indivíduos do sexo masculino. No entanto, mulheres também são acometidas em casos raros. Aproximadamente 8% das portadoras de DMD têm fraqueza muscular ou cardiomiopatia. A identificação precoce das alterações funcionais e motoras pode alterar a tomada de decisão clínica. Objetivo: Investigar as deficiências motoras e funcionais de 10 pacientes do sexo feminino com distrofinopatia diagnosticada por estudos clínicos, patológicos, genéticos e imuno-histoquímicos. Método: Estudo descritivo de uma amostra de portadoras sintomáticas de mutações DMD. As variáveis estudadas foram força muscular e desempenho funcional. Resultados: A prevalência foi de 10/118 (8,4%) de portadoras sintomáticas de DMD. Foram encontradas deleções em sete pacientes. A idade de início dos sintomas em portadoras de DMD foi variável. Pseudo-hipertrofia de panturrilhas, movimentos compensatórios, fraqueza muscular e aumento no tempo de execução de tarefas funcionais foram observados na maioria dos casos. Diferentemente dos homens com DMD, sete pacientes apresentaram fraqueza muscular assimétrica. A apresentação assimétrica da fraqueza muscular foi frequente, podendo afetar a postura e a funcionalidade. O desempenho funcional geralmente apresenta aumento no número de movimentos compensatórios. Não podemos sempre considerar o tempo como um bom marcador de funcionalidade para essa população, uma vez que não muda na mesma proporção que o número de compensações em todas essas pacientes. Conclusão: Fraqueza muscular assimétrica e movimentos compensatórios, ou ambos, podem ser encontrados em portadoras sintomáticas de DMD, o que pode afetar a postura e a funcionalidade dessas pacientes.

Detección de mutaciones causantes de distrofia muscular de Duchenne/Becker: reacción en cadena de la polimerasa Multiplex vs. Amplificación múltiple dependiente de ligación por sondas / Detection of mutations causing Duchenne and Becker muscular dystrophies: multiplex polymerase chain reaction vs. Multiplex ligation dependent probe amplification

RESUMEN Las distrofias musculares de Duchenne/Becker son enfermedades raras que reciben poca atención en nuestro medio. El objetivo del presente estudio fue implementar la técnica de amplificación múltiple dependiente de ligación por sondas (MLPA) y demostrar que tiene ventajas sobre la técnica de reacción en cadena de la polimerasa multiplex (PCR-multiplex). Se analizaron muestras de 40 individuos con diagnóstico presuntivo de distrofia muscular de Duchenne/Becker, primero por PCR-multiplex y luego por MLPA. Con la PCR-multiplex se detectaron 15 individuos con deleciones causales y con la técnica MLPA se logró diagnosticar a 21 individuos, cuatro duplicaciones y 17 deleciones. En conclusión, la técnica MLPA logra detectar mutaciones de tipo deleción y duplicación de exones, consiguiendo un mayor número de diagnósticos moleculares por alteraciones en el gen DMD.

ABSTRACT Duchenne and Becker muscular dystrophies are rare diseases that receive limited attention in our field. The objective of this study was to implement the Multiplex Ligation-dependent Probe Amplification technique (MLPA) and to demonstrate that it has advantages over the Multiplex Polymerase Chain Reaction (Multiplex PCR) technique. Samples from 40 individuals with a presumptive diagnosis of Duchenne and Becker muscular dystrophies were analyzed: first by Multiplex PCR and then by MLPA. Fifteen individuals with causal deletions were detected with Multiplex PCR, while the MLPA technique was able to diagnose 21 individuals, four duplications, and 17 deletions. In conclusion, the MLPA technique can detect mutations of the exon deletion and duplication type, yielding a larger number of molecular diagnoses due to alterations in the DMD gene.

Avances en el tratamiento de la distrofia de Duchenne / Advances in the treatment of Duchenne muscular dystrophy

La distrofia muscular de Duchenne es una enfermedad genéticamente determinada, ligada al cromosoma X y caracterizada clínicamente por producir debilidad muscular progresiva, con una incidencia de 1 por cada 3500-6000 varones nacidos. Es causada por la mutaciones en el gen DMD, el cual codifica la distrofina, una proteína sub-sarcolémica esencial para la estabilidad estructural del músculo. Los defectos genéticos en el gen DMD, se dividen en: deleciones (65%) duplicaciones (5-10%) y mutaciones puntuales (10-15%). Actualmente no se dispone de tratamiento curativo, el único fármaco que ha demostrado modificar la historia natural de la enfermedad (independientemente de la mutación genética) son los corticoides, los cuales están indicados en estadios tempranos de la enfermedad. En relación a los ensayos clínicos, en los últimos diez años se han experimentado grandes avances en el campo de las opciones terapéuticas, divididos en dos grandes dianas terapéuticas: 1) el área de las terapias génicas y 2) tratar de revertir o bloquear los procesos fisiopatológicos de la enfermedad, tales como inflamación, fibrosis, regeneración muscular, etc. Es probable que un tratamiento eficaz para la distrofia muscular de Duchenne requiera combinaciones que se apliquen tanto al defecto primario como las consecuencias fisiopatológicas secundarias.

Duchenne muscular dystrophy is a genetically determined disease, linked to the X chromosome, c haracterized clinically by producing progressive muscle weakness, with an incidence of 1 per 3500-6000 males born. It is caused by the mutation of the DMD gene, which encodes dystrophin, a sub-sarcolemmal protein essential for structural muscle stability. The genetic defects in the DMD gene are divided into: deletions (65%) duplications (5.10%) and point mutations (10-15%). At present there is no curative treatment, the only drug that has been shown to modify the natural history of the disease (independently of the genetic mutation) are corticosteroids, currently indicated in early stages of the disease. In relation to clinical trials, in the last ten years, has experienced great advances in the field of therapeutic options, divided into two major therapeutic targets: 1) the area of gene therapies and 2) trying to reverse or block the pathophysiological processes of the disease, such as inflammation, fibrosis, muscle regeneration, etc. It is likely that an effective treatment for Duchenne muscular dystrophy requires combinations of therapies that address both the primary defect and its secondary pathophysiological consequences.

Desempenho cognitivo através do mini-exame do estado mental na distrofia muscular de Duchenne / Cognitive performance by mini mental state examination in Duchenne muscular dystrophy

OBJETIVO: A distrofia muscular de Duchenne (DMD) é frequentemente associada à deficiência intelectual (DI) e ao prejuízo de funções superiores como leitura, raciocínio, lógica, e memória. O objetivo do estudo foi avaliar o desempenho cognitivo de pacientes com DMD através do Mini-Exame do Estado Mental (MEEM), um teste simples e rápido, usado como primeiro rastreio intelectual, principalmente quando baterias psicométricas complexas, dependentes de psicólogos especializados, não estão disponíveis. MÉTODO: Foi realizado um estudo observacional de trinta e quatro meninos com DMD, com idades entre 8 e 22 anos, separados em dois grupos de acordo com a presença de DI moderada-grave, conforme a definição clínica do funcionamento adaptativo do Manual Estatístico e Diagnóstico de Desordens Mentais 5º edição (DSM-5). Foram avaliados a pontuação no MEEM, marcos do desenvolvimento, independência nas atividades de vida cotidiana e capacidade de alfabetização. RESULTADOS: Os marcos motores e de linguagem estavam atrasados (16 meses), e a média no MEEM foi 21, ponto de corte mais baixo do que verificado em pares da mesma idade. O grupo com DI moderada-grave apresentou uma média de 12 no MEEM, e os subtestes de orientação, atenção e cálculo e linguagem foram os que demonstraram piores desempenhos. O ponto de corte de maior acurácia para distinguir DI moderada-grave nos pacientes com DMD foi 21. CONCLUSÃO: O MEEM apresentou adequada sensibilidade (100%) e especificidade (90%) para o ponto de corte de 21, revelando-se um bom método de triagem cognitiva para DI moderada-grave na DMD.

BACKGROUND: Duchenne muscular dystrophy (DMD) is often associated with intellectual disability (ID) and with impairment of higher mental functions as reading, learning, logical thinking and memory. The goal of this study was evaluate the cognitive performance of DMD patients by Mini-Mental State Examination (MMSE), first bedside screening test, widely used in pediatrics, when neuropsychologic batteries, dependent on specialized psychologists, are not easily available in public health system. METHODS: An observational study of thirty-four boys with DMD, aged 8-22 years, was performed, spliting this group into two sub-groups, according to the presence of moderate-severe, defined by Diagnostic and Statistical Manual of Mental Disorders (DSM-5) adaptative functioning clinical criteria. The MMSE scores, developmental milestones, independence in daily life activities and literacy skills were evaluated. RESULTS: Motor and language milestones were reached with 16 months, later than usual and mean on MMSE was 21, lower than in healthy pairs. In assessment by groups, patients with moderate-severe intellectual disability presented a performance in total MMSE (12) and orientation, attention/calculation and language MMSE subtests lower than patients without ID. The most accurate cutoff value on MMSE to distinguish moderate-severe intellectual disability in DMD patients was 21. CONCLUSION: This study has shown adequate sensitivity and specificity of the MMSE for detection of moderate-severe intellectual disability, with almost 100% sensitivity and 90% specificity for cutoff values of 21 points in DMD.

Preimplantation genetic diagnosis associated to Duchenne muscular dystrophy / Diagnóstico genético pré-implantacional associado à distrofia muscular de Duchenne

ABSTRACT Duchenne muscular dystrophy is the most common muscle disease found in male children. Currently, there is no effective therapy available for Duchenne muscular dystrophy patients. Therefore, it is essential to make a prenatal diagnosis and provide genetic counseling to reduce the birth of such boys. We report a case of preimplantation genetic diagnosis associated with Duchenne muscular dystrophy. The couple E.P.R., 38-year-old, symptomatic patient heterozygous for a 2 to 47 exon deletion mutation in DMD gene and G.T.S., 39-year-old, sought genetic counseling about preimplantation genetic diagnosis process. They have had a 6-year-old son who died due to Duchenne muscular dystrophy complications. The couple underwent four cycles of intracytoplasmic sperm injection (ICSI) and eight embryos biopsies were analyzed by polymerase chain reaction (PCR) for specific mutation analysis, followed by microarray-based comparative genomic hybridisation (array CGH) for aneuploidy analysis. Preimplantation genetic diagnosis revealed that two embryos had inherited the maternal DMD gene mutation, one embryo had a chromosomal alteration and five embryos were normal. One blastocyst was transferred and resulted in successful pregnancy. The other embryos remain vitrified. We concluded that embryo analysis using associated techniques of PCR and array CGH seems to be safe for embryo selection in cases of X-linked disorders, such as Duchenne muscular dystrophy.

RESUMO A distrofia muscular de Duchenne é a doença muscular mais comum observadas em crianças do sexo masculino. Atualmente, não há terapia eficaz disponível para distrofia muscular de Duchenne, portanto, é essencial o diagnóstico pré-natal e o aconselhamento genético para reduzir o nascimento desses meninos. Relatamos um caso de diagnóstico genético pré-implantação associado à distrofia muscular de Duchenne. O casal E.P.R., 38 anos, heterozigota, sintomática para uma mutação de deleção dos éxons 2 a 47 no gene DMD e G.T.S., 39 anos, buscaram aconselhamento genético sobre o processo de diagnóstico genético pré-implantação. O casal relatou que tiveram um filho de 6 anos que morreu devido a complicações da distrofia muscular de Duchenne. Os pacientes realizaram quatro ciclos de injeção intracitoplásmica de espermatozoides (ICSI) e oito biópsias de embriões foram analisadas por reação em cadeia da polimerase (PCR) para análise de mutação específica, seguida hibridação genômica comparativa baseada em microarranjos ( array CGH) para a pesquisa de aneuploidias. O diagnóstico genético pré-implantação revelou que dois embriões haviam herdado a mutação materna no gene DMD , um embrião tinha uma alteração cromossômica e cinco embriões eram normais. Um blastocisto foi transferido e resultou em gravidez bem sucedida. Os outros embriões permanecem vitrificados. Concluímos que a análise de embriões utilizando técnicas associadas de PCR e CGH array mostrou-se segura para a seleção de embriões em casos de doenças ligadas ao X, como a distrofia muscular de Duchenne.

Brazilian consensus on Duchenne muscular dystrophy. Part 1: diagnosis, steroid therapy and perspectives / Consenso brasileiro sobre distrofia muscular de Duchenne - Parte 1 diagnóstico, corticoterapia e perspectivas

ABSTRACT Significant advances in the understanding and management of Duchenne muscular dystrophy (DMD) took place since international guidelines were published in 2010. Our objective was to provide an evidence-based national consensus statement for multidisciplinary care of DMD in Brazil. A combination of the Delphi technique with a systematic review of studies from 2010 to 2016 was employed to classify evidence levels and grade of recommendations. Our recommendations were divided in two parts. We present Part 1 here, where we describe the guideline methodology and overall disease concepts, and also provide recommendations on diagnosis, steroid therapy and new drug treatment perspectives for DMD. The main recommendations: 1) genetic testing in diagnostic suspicious cases should be the first line for diagnostic confirmation; 2) patients diagnosed with DMD should have steroids prescribed; 3) lack of published results for phase 3 clinical trials hinders, for now, the recommendation to use exon skipping or read-through agents.

RESUMO Avanços na compreensão e no manejo da distrofia muscular de Duchenne (DMD) ocorreram desde a publicação de diretrizes internacionais em 2010. Nosso objetivo foi elaborar um consenso nacional baseado em evidências de cuidado multidisciplinar dos pacientes com DMD no Brasil. Utilizamos a técnica de Delphi combinada com revisão sistemática da literatura de 2010 a 2016 classificando níveis de evidência e graus de recomendação. Nossas recomendações foram divididas em duas partes. Apresentamos aqui a parte 1, descrevendo a metodologia utilizada e conceitos gerais da doença, e fornecemos recomendações sobre diagnóstico, tratamento com corticosteroides e novas perspectivas de tratamentos medicamentosos. As principais recomendações: 1) testes genéticos deveriam ser a primeira linha para confirmação de casos suspeitos; 2) pacientes com diagnóstico de DMD devem receber corticosteroides; 3) por enquanto, a falta de publicações de resultados dos ensaios clínicos de fase 3, dificulta recomendações de uso medicamentos que "saltam exons" ou "passam" por código de parada prematura.

Estudo Clínico e Molecular na Distrofia Muscular de Duchenne / Clinical and Molecular Study on Duchenne Muscular Dystrophy

Fundamentos: A forma de Duchenne é a mais comum e grave das distrofias musculares. De herança recessivaligada ao cromossoma X, acomete meninos e afeta os músculos estriados e o miocárdio. Origina-se de mutaçõesno gene da distrofina, o maior gene humano com 79 éxons. Objetivos: Verificar as alterações cardíacas iniciais em pacientes pediátricos com distrofia muscular de Duchenne (DMD) e realizar o estudo molecular das alterações no gene da distrofina. Métodos: Estudo prospectivo incluindo pacientes pediátricos portadores de DMD, com avaliação clínica, medição do nível sérico de creatinofosfoquinase, eletrocardiograma, ecoDopplercardiograma e eletrocardiografia dinâmica e genotipagem do DNA, com amplificação dos 18 éxons mais acometidos.Resultados: Foram estudados 11 meninos de 6-14 anos de idade. Não havia alterações importantes ao exameclínico cardiológico. Observou-se aumento da creatinofosfoquinase em todos os pacientes. O eletrocardiogramamostrou alterações precoces, com ondas R altas em V1 (n=7), bloqueio de ramo direito (n=2), ondas delta e PR curto (n=1) e distúrbio da repolarização ventricular (n=1). Em 4 pacientes, o ecocardiograma evidenciou sinaisde disfunção sistólica. O eletrocardiograma dinâmico (Holter) mostrou alteração em 4 pacientes: com muitas extrassístoles (n=3) e com síndrome de Wolff-Parkinson-White (n=1). Todas as crianças recebiam corticoterapia. Não houve correlação significativa entre a deleção do éxon 52 e arritmias (p=0,43). O estudo molecular evidenciou deleção do éxon 52 nos 4 pacientes com cardiomiopatia dilatada, sendo que em 2 havia deleção concomitante nos éxons 1 e 50, respectivamente. Nos outros 7 pacientes havia deleção nos éxons 48, 51, 52 e 57.Conclusões: O eletrocardiograma mostrou as primeiras alterações nos pacientes pediátricos com DMD. Nos casos com cardiomiopatia dilatada e arritmia, detectou-se deleção do éxon 52.

Background: Duchenne Dystrophy is the most common and severe form of muscular dystrophy. It has an X chromosome-linked recessiveinheritance and affects boys’ striated muscles and myocardium. It is caused by mutations in the dystrophin gene, the largest human gene, composed of 79 exons. Objectives: To check the early cardiac changes in pediatric patients with Duchenne muscular dystrophy (DMD) and carry out the molecular study of changes in the dystrophin gene.Methods: Prospective study involving pediatric patients with DMD, with clinical assessment, measurement of serum levels of creatine phosphokinase, electrocardiogram, Doppler echocardiography and dynamic electrocardiography and DNA genotyping, with amplificationof the 18 most affected exons. Results: A group of 11 boys aged 6-14 years was studied. Clinical cardiological examination did not reveal any major changes. An increase in creatinine phosphokinase was detected in all patients. Electrocardiogram showed early changes, with high R waves in V1 (n=7) right bundle branch block (n=2), delta waves and short PR interval (n=1), and signs of disturbance of ventricular repolarization (n=1). Echocardiogramshowed signs of systolic dysfunction. Dynamic electrocardiogram (Holter) showed changes in 4 patients: with many extrasystoles (n=3) andWolff-Parkinson-White syndrome (n=1). All children received corticosteroid therapy. There was no significant correlation between exon52 deletion and arrhythmias (p=0.43). The molecular study revealed an exon 52 deletion in 4 patients with dilated cardiomyopathy, of which2 had concomitant deletion of exons 1 and 50, respectively. Other 7 patients had deletions of exons 48, 51, 52 and 57. Conclusions: Electrocardiogram showed the first changes in pediatric patients with DMD. In cases with dilated cardiomyopathy and arrhythmia, the deletion of exon 52 was detected.

Influência da adequação postural em cadeira de rodas na função respiratória de pacientes com distrofia muscular de Duchenne / Influence of wheelchair positioning aids on the respiratory function of patients with Duchenne muscular dystrophy

O objetivo deste estudo foi avaliar a influência da adequação postural em cadeira de rodas na função respiratória de pacientes com distrofia muscular de Duchenne (DMD). Participaram 12 pacientes com diagnóstico de DMD e que possuíam cadeira de rodas adaptada com idade variando de 10 a 22 anos. Cada indivíduo foi avaliado na própria cadeira de rodas e em uma cadeira de rodas padrão, ou seja, sem reclinação ou tilt. As cadeiras dos participantes possuíam adaptações no encosto e no assento, confeccionados de acordo com as especificidades de cada paciente. A avaliação consistiu em mensurar o volume minuto (VM), volume corrente (VC), capacidade vital forçada (CVF), pressões inspiratória (PImax) e expiratória (PEmax) máximas e pico de fluxo expiratório (PFE). Para análise dos dados, foi utilizado o teste t pareado, adotando-se o nível de significância de 0,05. As adaptações resultaram em melhores valores estatisticamente significativos de todos os parâmetros respiratórios: VM (8.963,3 e 10.762,5 mL/min; p=0,028), VC (319,1 e 433,6 mL; p=0,005), CVF (1.476,3 e 1.850 mL; p=0,005), PImax (-41,2 e -51,2 cmH2O; p=0,022), PEmax (29,6 e 36,7 cmH2O; p=0,004) e PFE (162,1 e 185 L/min; p=0,018). Nossos resultados sugerem que a adequação postural em cadeira de rodas influenciou positivamente a função respiratória de pacientes com DMD.

The purpose of this study was to determine the influence of wheelchair positioning aids on the respiratory function of patients with Duchenne muscular dystrophy (DMD). Twelve non-ambulatory DMD patients, between 10 to 22 years of age, were evaluated. They were assessed in their adapted wheelchairs and in a standard wheelchair without tilt or reclining. The wheelchairs of the participants possessed adaptations in the backrest and the seat, made according to the specifics of each patient. Minute volume (MV), tidal volume (TV), forced vital capacity (FVC), maximum inspiratory (MIP) and expiratory pressures (MEP) and peak expiratory flow (PEF) were measured. For data analysis we used the paired t-test adopting the significance level of 0.05. The positioning aids resulted in statistically significant better values of all respiratory parameters: MV (8,963.3 and 10,762.5 mL/min; p=0.028), TV (319.1 and 433.6 mL; p=0.005), FVC (1,476.3 and 1,850 mL; p=0.005), MIP (-41.2 and -51.2 cmH2O; p=0.022), MEP (29.6 and 36.7 cmH2O; p=0.004) and PEF (162.1 and 185 L/min; p=0.018). These results may suggest that wheelchair positioning aids can positively influence pulmonary function for non-ambulatory DMD patients.

Utility of MLPA in mutation analysis and carrier detection for Duchenne muscular dystrophy.

CONTEXT: Multiplex ligation probe amplification (MLPA) is a new technique to identify deletions and duplications and can evaluate all 79 exons in dystrophin gene in patients with Duchenne muscular dystrophy (DMD). Being semi-quantitative, MLPA is also effective in detecting duplications and carrier testing of females; both of which cannot be done using multiplex PCR. It has found applications in diagnostics of many genetic disorders. AIM: To study the utility of MLPA in diagnosis and carrier detection for DMD. MATERIALS AND METHODS: Mutation analysis and carrier detection was done by multiplex PCR and MLPA and the results were compared. RESULTS AND CONCLUSIONS: We present data showing utility of MLPA in identifying mutations in cases with DMD/BMD. In the present study using MLPA, we identified mutations in additional 5.6% cases of DMD in whom multiplex PCR was not able to detect intragenic deletions. In addition, MLPA also correctly confirmed carrier status of two obligate carriers and revealed carrier status in 6 of 8 mothers of sporadic cases.

Genetic Analysis of Dystrophin Gene for Affected Male and Female Carriers with Duchenne/Becker Muscular Dystrophy in Korea

Duchenne and Becker muscular dystrophy (DMD/BMD) are X-linked recessive disorders caused by mutation in dystrophin gene. We analyzed the results of a genetic test in 29 DMD/BMD patients, their six female relatives, and two myopathic female patients in Korea. As the methods developed, we applied different procedures for dystrophin gene analysis; initially, multiplex polymerase chain reaction was used, followed by multiplex ligation-dependent probe amplification (MLPA). Additionally, we used direct DNA sequencing for some patients who had negative results using the above methods. The overall mutation detection rate was 72.4% (21/29) in DMD/BMD patients, identifying deletions in 58.6% (17/29). Most of the deletions were confined to the central hot spot region between exons 44 and 55 (52.9%, 7/19). The percentage of deletions and duplications revealed by MLPA was 45.5% (5/11) and 27.2% (3/11), respectively. Using the MLPA method, we detected mutations confirming their carrier status in all female relatives and symptomatic female patients. In one patient in whom MLPA revealed a single exon deletion of the dystrophin gene, subsequent DNA sequencing analysis identified a novel nonsense mutation (c.4558G > T; Gln1520X). The MLPA assay is a useful quantitative method for detecting mutation in asymptomatic or symptomatic carriers as well as DMD/BMD patients.

Disease-specific induced pluripotent stem cells: a platform for human disease modeling and drug discovery

The generation of disease-specific induced pluripotent stem cell (iPSC) lines from patients with incurable diseases is a promising approach for studying disease mechanisms and drug screening. Such innovation enables to obtain autologous cell sources in regenerative medicine. Herein, we report the generation and characterization of iPSCs from fibroblasts of patients with sporadic or familial diseases, including Parkinson's disease (PD), Alzheimer's disease (AD), juvenile-onset, type I diabetes mellitus (JDM), and Duchenne type muscular dystrophy (DMD), as well as from normal human fibroblasts (WT). As an example to modeling disease using disease-specific iPSCs, we also discuss the previously established childhood cerebral adrenoleukodystrophy (CCALD)- and adrenomyeloneuropathy (AMN)-iPSCs by our group. Through DNA fingerprinting analysis, the origins of generated disease-specific iPSC lines were identified. Each iPSC line exhibited an intense alkaline phosphatase activity, expression of pluripotent markers, and the potential to differentiate into all three embryonic germ layers: the ectoderm, endoderm, and mesoderm. Expression of endogenous pluripotent markers and downregulation of retrovirus-delivered transgenes [OCT4 (POU5F1), SOX2, KLF4, and c-MYC] were observed in the generated iPSCs. Collectively, our results demonstrated that disease-specific iPSC lines characteristically resembled hESC lines. Furthermore, we were able to differentiate PD-iPSCs, one of the disease-specific-iPSC lines we generated, into dopaminergic (DA) neurons, the cell type mostly affected by PD. These PD-specific DA neurons along with other examples of cell models derived from disease-specific iPSCs would provide a powerful platform for examining the pathophysiology of relevant diseases at the cellular and molecular levels and for developing new drugs and therapeutic regimens.