INTRODUÇÃO: As distrofias musculares (DM) constituem um grupo de doenças genéticas caracterizadas por fraqueza muscular progressiva decorrente da degeneração irreversível do tecido muscular esquelético. O comprometimento da função respiratória é um sinal precoce da progressão da doença. A fraqueza progressiva dos músculos respiratórios torna o paciente com distrofia muscular incapaz de realizar inspirações profundas de forma independente para promover uma tosse eficaz. Portanto, torna-se necessário fornecer insuflações regulares com volumes que o paciente aprende a empilhar com o fechamento da glote, até que atinja a capacidade de insuflação máxima (CIM). A insuflação pulmonar minimiza complicações, tais como atelectasias e pneumonias, e permite níveis apropriados de ventilação e troca gasosa adequada nas eventuais complicações pulmonares, as quais impõem carga sobre os músculos respiratórios. Este mesmo processo pode representar uma alternativa para otimizar a função respiratória (FP) por meio do aumento do pico de fluxo de tosse (PFT) e manter a complacência pulmonar. Nos pacientes com distrofia muscular causada por mutações do gene da distrofina, a abordagem respiratória aumentou a sobrevida, sendo hoje as complicações cardiovasculares a maior causa de mortalidade. Entretanto, a manobra de empilhamento de ar ainda não foi adequadamente avaliada nestes pacientes. OBJETIVOS: Investigar a efetividade e a segurança desta manobra durante um período de um ano de treinamento em pacientes com Distrofia Muscular de Duchenne (DMD). MÉTODOS: Em 60 pacientes com DMD, cardiopatas e não cardiopatas, foram avaliados a FP, o PFT e a resposta cardíaca como frequência cardíaca (FC), pressão arterial (PA) e sintomas associados, antes, durante a sustentação e após a manobra de empilhamento de ar, em uma primeira avaliação, e depois de um ano de orientação e treinamento. Após o treinamento, foi avaliada, também, a variabilidade da frequência cardíaca (VFC). RESULTADOS: Houve um ganho da Capacidade vital forçada (CVF) e do PFT após um ano de treinamento (p < 0,05), Houve uma correlação linear entre o ganho de CIM e o PFT. Houve diferença na FC e na PA sistólica (PAS) durante a sustentação da manobra em comparação aos outros tempos, sendo que, no grupo de pacientes cardiopatas, a resposta cardíaca foi mais evidente, associada, em alguns pacientes, a sintomas relacionados a baixo débito cardíaco, tais como náuseas e tonturas (p < 0,05). Houve diferença significativa nos valores da VFC durante a manobra. (p < 0,05). CONCLUSÃO: O treinamento da manobra de empilhamento, durante um ano, proporcionou ganho e manutenção da função pulmonar, além de alterações cardíacas significativas associadas a sintomas apenas durante a sustentação da manobra, principalmente nos pacientes cardiopatas / INTRODUCTION: Muscular dystrophy (MD) is a genetic disease characterized by progressive muscle weakness resulting from irreversible degeneration of skeletal muscle tissue. An early sign of disease progression is the impairment of respiratory function. The progressive respiratory muscle weakness makes the patient with muscular dystrophy be unable to perform independent deep breaths in order to promote an effective cough. Therefore, it becomes necessary to provide regular inflations with volumes until it reaches the maximum insufflation capacity (MIC). Pulmonary insufflation minimizes complications such as pneumonia and atelectasis, and allows proper ventilation levels and adequate gas exchange in pulmonary complications. This same process can be an alternative to optimize pulmonary function (PF) by increasing peak cough flow (PCF) and maintain pulmonary compliance. In patients with muscular dystrophy respiratory approach increased their survival. Nowadays, cardiovascular complications is main a leading cause of mortality. However the air stacking has not been adequately evaluated in these patients. OBJECTIVES: To investigate the effectiveness of air stacking exercise and its safety profile in DM. METHODS: We evaluated 60 patients with DMD and with and without heart disease, the PF and PCF; cardiac response as heart rate (HR), blood pressure (BP), and associated symptoms before, during sustained time and after air stacking in the first review, and a year after being advised and trained. After twelve months was also measured the heart rate variability (HRV). RESULTS: There was a statistically difference in forced vital capacity (FVC) and PCF after a year of air stacking (p < 0.05). There was a linear correlation between MIC and PCF (R=0.8). Differences in HR and blood arterial systolic pressure (BPS) at sustainet time of air stacking compared to other times, moreover, in the heart disease group cardiovascular response was more evident, associated in some patients with low cardiac output related symptoms such as nausea and dizziness (p < 0.05). There was a significant difference in HRV values during air stacking (p < 0.05). CONCLUSION: The air stacking for twelvemonths provided gain and maintenance of pulmonary function, beyond a significant cardiac response abnormalities only during sustained time specially in heart disease patients associated with symptoms

INTRODUÇÃO: As distrofias musculares progressivas e a amiotrofia espinhal progressiva (AEP) são doenças neuromusculares (DNM) caracterizadas pela degeneração irreversível das fibras musculares, a qual leva à fraqueza muscular e à incapacidade motora. Qualidade de Vida Relacionada à Saúde (QVRS) inclui subjetividade, multidimensionalidade, aspectos negativos e positivos diante da percepção e da expectativa individual de vida; sofre influência cultural. JUSTIFICATIVA: A avaliação da QVRS é essencial para definir a resposta ao tratamento multidisciplinar ou efetivo do paciente com DNM e para sinalizar medidas destinadas a incrementar o sucesso terapêutico. OBJETIVOS: Validar os questionários Life Satisfaction Índex for Adolescents (LSI-A) versão pais e versão paciente e Pediatric Quality of Life Inventory Duchenne (PedsQL DMD) versão pais e versão paciente para o português; avaliar a QVRS dos pacientes com distrofia muscular de Duchenne (DMD), amiotrofia espinhal progressiva (AEP) ou distrofia muscular de cinturas (DMC); avaliar a QV familiar e da mãe/cuidadora. METODOLOGIA: Os questionários LSI-A e PedsQL DMD foram validados obedecendo às etapas de adaptação cultural e validação. Após validação, o questionário LSI-A foi aplicado a pacientes com DMD, AEP ou DMC; o PedsQL Duchenne foi aplicado aos pacientes com DMD e o PedsQL NM a pacientes com AEP ou DMC. Os pais dos pacientes responderam ao FQoL e as mães/cuidadoras ao WHOQOL-Bref. Para cálculo estatístico utilizaram-se: testes alfa de Cronbach, CIC, Pearson, Curva ROC para a validação, e Mann Whitney, Friedman e Dunn para a aplicação. RESULTADOS: Quanto à validação: Probe final do LSI-A versão pais, 97% e versão paciente, 95%; PesdQL DMD versão pais, 99% e versão paciente, 97%, sinalizando compreensão excelente; o teste ? de Cronbach no LSI-A versão pais e paciente, respectivamente, obteve escore geral 0.87 e 0.89; no PesdsQL versão pais e versão paciente, respectivamente, escore geral 0.87 e 0.84. Em ambos foi evidenciado alta confiabilidade dos itens. Quanto à aplicação do LSI-A versão pais e pacientes para avaliação da QVRS, quando comparada aos controles, houve maior número de domínios significantes em pacientes com DMD, AEP ou DMC, nesta ordem. A QVRS mediante aplicação do questionário PedsQL módulo DMD e NM obedeceu a esta mesma sequência. CONCLUSÕES: Conforme os dados psicométricos, os questionários são válidos para serem aplicados a pacientes com DNM e respectivos pais, como segue: LSI-A versão pais e versão paciente a pacientes com DMD, AEP e DMC e respectivos pais, e PedsQL 3.0 Duchenne versão pais e paciente a pacientes com DMD e respectivos pais. A QVRS apresentou-se mais satisfatória nos pacientes com DMC, seguidos pelos pacientes com AEP tipo II e III e, por último, pelos pacientes com DMD. A QV da família apresentou-se reduzida quanto aos aspectos relativos ao bem estar material, particularmente no caso das famílias dos pacientes com DMD. A QV das mães/cuidadoras, decresceu conforme o aumento da idade dos pacientes, quanto aos aspectos psicológicos, sociais e ambientais, em especial a das mães/cuidadoras dos pacientes com AEP / INTRODUCTION: Progressive muscular dystrophies and spinal muscular atrophy (SMA) are neuromuscular diseases (NMD) characterized by irreversible degeneration of muscle fibers which leads to muscle weakness and motor disability. Health-related quality of life (HRQoL) includes subjectivity, multidimensionality, negative and positive aspects on the perception and individual life expectancy; in addition, it suffers cultural influences. BACKGROUND: The assessment of HRQoL is essential to define the response to the multidisciplinary or effective treatment of patients with NMD and to indicate measures to increase the therapeutic success. OBJECTIVES: to validate to the Portuguese the following HRQoL instruments for patients with NMD: Life Satisfaction Index for Adolescents (LSI-A) and Pediatric Quality of Life Inventory Duchenne (PedsQL Duchenne); to evaluate the HRQoL of patients with Duchenne muscular dystrophy (DMD), spinal muscular atrophy (SMA) or limb girdle muscular dystrophy (LGMD), and to assess the family and caregiver QoL. METHODOLOGY: The LSI-A and PedsQL Duchenne questionnaires were validated obeying the stages of cultural adaptation and validation. After validation, the LSI-A questionnaire was administered to patients with DMD, SMA or LGMD, the PedsQL Duchenne to patients with DMD, and the PedsQL NM to patients with SMA or LGMD. Parents of patients responded to FQoL and mothers/caregiver to WHOQOL-Bref. For statistical calculations were used: ? test Cronbach, CIC, Pearson, ROC curve for validation, and Mann Whitney, Friedman and Dunn for the application. RESULTS: Validation: the final \"Probe\" of the LSI-A parents version was 97% and patient version, 95%; PesdQL DMD parents version, 99% and patient version, 97%, indicating excellent comprehension; Cronbach\'s alfa test at LSI-A parents and patients version, respectively, achieved overall score 0.87 and 0.89; at PesdsQL parents and patient version, respectively, were obtained overall score 0.87 and 0.84. At both it was demonstrated high reliability of the items. At the application of LSI-A parents and patients version to measure HRQoL compared to controls, there was a greater number of significant dominions in DMD, SMA and LGMD, in that order. The PedsQL DMD module and NM followed the same sequence. CONCLUSIONS: According with the psychometric data, questionnaires are valid to be applied to parents and patients with NMD, as follows: LSI-A to parents and patients with DMD, SMA and LGMD, and PedsQL 3.0 Duchenne to patients with DMD and parents. The HRQL was more satisfactory in patients with LGMD, followed by patients with SMA and, finally, by DMD patients. The family QOL presented reduction of the aspects concerning material well-being, particularly for families of patients with DMD. The QoL of mothers decreased with the increase of the patients\' age, concerning the psychological, social and environmental aspects, in particular for the mothers of patients with SMA

Les dystrophies rétiniennes héréditaires (DRH) sont un groupe de maladies génétiquement et cliniquement hétérogènes, lesquelles se caractérisent par une perte progressive de la vision. La choroïdérémie (CHM) est une choriorétinopathie qui représente environ 3% des DRH. Elle se caractérise par une cécité nocturne durant l’enfance suivie par une perte du champ visuel périphérique lente et progressive. Cela aboutit à une cécité vers l’âge de 40 à 50 ans. Généralement, la vision centrale demeure préservée plus longtemps. Génétiquement, la maladie est causée par des mutations dans le gène CHM localisé dans le chromosome X qui code pour la Rab Escort Protein 1 (REP1).Cette protéine est impliquée dans la prénylation des Rab GTPasas qui régulent le trafic vésiculaire au sein de la cellule. La plupart des mutations responsables de la maladie sont des mutations pertes de fonction. La conséquence de ces mutations est l’absence de REP1 entrainant un défaut de prénylation des Rabs. Ce qui cause la dégénérescence des photorécepteurs, de l’épithélium pigmentaire rétinien (EPR) et de la choroïde. À ce jour, il n’existe pas de thérapie pour la CHM. Cependant, le diagnostic précoce de la maladie et son évolution lente donnent une fenêtre thérapeutique large et en font un candidat idéal pour la réussite d’un traitement.En raison de l’absence d’un modèle animal pertinent pour tester de nouvelles thérapies pour cette maladie, nous avons développé un modèle cellulaire humain d’EPR in vitro dérivé des cellules pluripotentes induites propres au patient. Ce tissu est morphologiquement et fonctionnellement représentatif de l’EPR in vivo et reproduit les défauts biochimiques de prénylation présents dans la CHM. De ce fait, il s’agit d’un modèle puissant pour évaluer l’efficacité de différentes approches thérapeutiques. Dans cette perspective, nous avons étudié une approche de thérapie génique par AAV2/5 afin de fournir le gène CHM dans le cas particulier de mutation faux sens et l’utilisation d’une translational read-through inducing drug (TRID) PTC124 pour le traitement des mutations non-sens.J’ai démontré pour la première fois la faisabilité de la thérapie génique pour la CHM dans le cas d’une expression résiduelle de REP1 muté, permettant de considérer les patients porteurs de mutations faux sens comme éligible à des essais cliniques de thérapie génique. De plus, j’ai démontré que l’efficacité de PTC124 peut être dépendante du type cellulaire. Dans l’ensemble, mes résultats suggèrent que l’efficacité de la molécule semblerait dépendre de la conservation de l’acide aminé muté et de sa localisation dans le domaine fonctionnel de REP1. Nous avons ainsi mis en valeur que le contexte génétique devrait être pris en compte dans la perspective d’une thérapie avec TRID pour cette maladie ainsi que d’autres pathologies.Pour conclure, j’ai souligné le potentiel prédictif du modèle d’EPR dérivé d’iPSc propre au patient pour évaluer de nouvelles approches thérapeutiques en l’absence d’un modèle animal approprié avant les essais cliniques. / Inherited retinal dystrophies (IRDs) are a class of genetically and clinically heterogeneous diseases, which are characterized by a progressive loss of vision. Choroideremia (CHM) is a chorioretinopathy, which accounts for ~3% of all IRDs. It is characterized by night blindness in childhood, followed by slow and progressive loss of the peripheral visual field. This results in legal blindness by the fourth to fifth decade of life. Generally, central vision is preserved till late in life. Genetically, the disease is caused by mutations in the CHM gene located on the X chromosome and encoding the Rab Escort Protein 1 (REP1). This protein is involved in the prenylation of Rab GTPasas, which regulate vesicular cell trafficking. Most of the disease-causing mutations are loss-of-function and the absence of REP1 leads to a Rab prenylation defect and subsequent degeneration of photoreceptors, retinal pigment epithelium (RPE) and underlying choroid. To date, an established therapy is not available for CHM, but the early diagnosis and its slow evolution provide a large therapeutic window, that renders this disease a good candidate for successful treatment.In order to palliate the lack of a pertinent animal model for testing novel disease therapies, we developed a human cellular model using patient-specific induced pluripotent stem cells (iPSc)-derived RPE. This tissue is morphologically and functionally representative of the RPE in vivo, and reproduces the biochemical prenylation defect present in CHM. Therefore, it is a powerful model to evaluate the efficacy of different therapeutic approaches. Along this line, we investigated a gene augmentation approach, via AAV2/5 delivery of the CHM gene in the particular case of a CHM missense mutation, and the use of the translational read-through inducing drug (TRID) PTC124 for treating CHM nonsense mutations.I demonstrated for the first time the feasibility of gene augmentation therapy for CHM in the case of residual mutated REP1 expression, suggesting that missense-carrying patients can be considered for inclusion in clinical gene therapy trials. Moreover, I showed that the efficiency of PTC124 may be dependent on the cell type. In addition, my results suggest that drug efficiency likely depends on the conservation of the mutated amino acid residue and its localization with regards to REP1 functional domains. We thus highlight that genetic considerations should be taken into account when considering TRID therapy for this and other disorders.Taken together, I highlighted the predictive potential of the patient-specific iPSc-derived RPE model for screening of novel and varied therapeutic approaches in the absence of a suitable animal model prior to clinical translation.

Devido à carência de avaliações para Distrofia Muscular de Duchenne (DMD), fisioterapeutas desenvolveram e testaram a confiabilidade da Functional Evaluation Duchenne Muscular Dystrophy (FES-DMD). Visando otimizar sua aplicação foi necessário um software. O objetivo deste estudo foi desenvolver e testar a usabilidade de software para aplicação da FES-DMD. Para desenvolver o software foi necessário um engenheiro, um programador e uma fisioterapeuta. Após finalização foi realizada avaliação técnica por cinco pareceristas e aplicado teste de usabilidade com quinze fisioterapeutas especialistas, para avaliar o uso do software na prática clínica e coletar o tempo de aplicação da FES-DMD. De acordo com as características exigidas o software foi desenvolvido com especificações: linguagem Visual Basic. Net, base de dados SQL Compact Server, Plataforma Windows XP sp3 ou superiores, Hardware de suporte, tela com resolução 1024X768 e formato do vídeo WMV/MP4. Estas permitem que o software tenha banco de dados seguro, cadastro de usuários, visualização de filmes, preenchimento da escala, cálculo do escore e geração de relatório. Como resultados, a avaliação técnica contribuiu com Layout e o teste de usabilidade mostrou que dez de quinze fisioterapeutas concordam fortemente que o software é usável na prática clínica, três concordam, enquanto que um discorda e outro discorda fortemente. Com relação ao tempo de aplicação, a FESDMD no software se mostrou mais rápida (p < 0.001). Foi possível desenvolver software para aplicação da FES-DMD. O instrumento promove ganho de tempo do fisioterapeuta, armazena dados e imagens de forma segura, gera relatórios e é usável na prática clínica / Due to the lack of reviews for Duchenne Muscular Dystrophy (DMD), physiotherapists have developed and tested a confiabiliade Functional Evaluation of Duchenne Muscular Dystrophy (FES-DMD). In order to optimize your application was necessary software. The aim of this study was to develop and test the usability of software for application of FES-DMD. To develop the necessary software was an engineer, a programmer and a physiotherapist. After finalizing technical evaluation was carried out for five referees and applied usability testing with fifteen physiotherapists experts to evaluate the use of software in clinical practice and collect the time of application of FES-DMD. According to the characteristics required software has been developed with specifications: Visual Basic language.Net, database SQL Server Compact Platform, Windows XP sp3 or higher, Hardware Support, 1024X768 screen resolution and video format WMV/MP4. These allow the software to be secure database, user registration, inhouse movies, completing the scale score calculation and reporting. As a result, the technical evaluation contributed Layout and usability test showed that ten fifteen physiotherapists strongly agree that the software is usable in clinical practice, three agree, while one disagreed and one strongly disagrees. Regarding the time of application, the FES- DMD in software is faster (p < 0.001). It was possible to develop software for the application of FES- DMD. The instrument promotes gain time physiotherapist, stores images and data securely, generate reports, and is usable in clinical practice

Introdução: A distrofia muscular de Duchenne (DMD) é uma doença genética recessiva. Caracterizada pelo enfraquecimento progressivo e irreversível da musculatura, levando a um quadro grave de deficiência física. Devido às alterações motoras presentes na DMD, é relevante verificar dispositivos de interação que auxiliem na funcionalidade e participação social, principalmente utilizando tecnologia e atualidades de ambientes virtuais. Objetivo: Identificar qual dispositivo de interação virtual propicia melhor desempenho em uma tarefa virtual em indivíduos com DMD. Método: Foram incluídos no estudo, 120 indivíduos, 60 com DMD entre 9 e 34 anos (média 16 anos) e 60 indivíduos com desenvolvimento típico pareados por sexo e idade (grupo controle). Foi utilizada uma tarefa virtual, que consiste em alcançar o maior número de bolhas, durante as fases de aprendizagem motora (aquisição, retenção e transferência) utilizando diferentes interfaces (Kinect, Leap Motion ou Touch Screen). Para análise estatística utilizou-se o número de bolhas alcançadas para cada participante. Resultados: Todos os participantes tiveram melhora no seu desempenho com a prática, independente da interface usada. Porém o grupo DMD, obteve resultado inferior quando comparado ao grupo controle. Houve melhora significativa no desempenho, em uma das fases, com a utilização da interface Leap Motion para grupo DMD, e Touch Screen para o grupo controle. Conclusão: O desempenho dos indivíduos com DMD é inferior quando comparado ao grupo controle, em todas as interfaces, devido a fraqueza muscular advinda da progressão da doença. Porém, há a possibilidade de melhorar o desempenho em uma tarefa, com a utilização que utilize dispositivo virtual, como o Leap Motion, exigindo funcionalidade de grupos musculares distais, nos indivíduos com distrofia muscular / Introduction: Duchenne muscular dystrophy (DMD) is a recessive genetic disease. Characterized by progressive and irreversible weakening of the musculature, leading to a serious physical disability. Due to the motor alterations present in the DMD, it is important to verify interaction devices that aid in functionality and social participation, mainly using technology and the news of virtual environments. Objective: To identify which virtual interaction device is best to provide performance in a virtual task in individuals with DMD. Methods: The study included 120 individuals, 60 DMD ranging from 9 to 34 years (mean 16 years) and 60 typically developed individuals matched by age and gender (control). A virtual task was used to achieve the greatest number of bubbles during the motor learning (acquisition, retention and transfer) phases, using different interfaces (Kinect, Leap Motion or Touch Screen). For statistical analysis, the number of bubbles reached for each participant was used. Results: All participants improved their performance with practice, regardless of the interface used. However, the DMD group had lower results when compared to the control group. There was a significant performance improvement in one of the phases, using the Leap Motion interface for DMD group, and Touch Screen for the control group. Conclusion: The performance of individuals with DMD is lower when compared to the control group, at all interfaces due to muscle weakness due to disease progression. However, there is the possibility of improving performance in a task using virtual device, such as Leap Motion, requiring functionality of distal muscle groups in individuals with muscular dystrophy

« Myopathie héréditaire » est un terme générique pour les maladies génétiques rares caractérisées par une faiblesse musculaire et une hypotonie avec ou sans atrophie musculaire. Les personnes atteintes d'une forme légère peuvent présenter des contractures, une scoliose, une hyporéflexie ou des caractéristiques dysmorphiques, et les plus sévères peuvent être accompagnées de symptômes cardiaques ou respiratoires pouvant s'avérer mortel. Alors que les méthodes de séquençage de nouvelle génération basées sur l'ADN ont considérablement accéléré la découverte de gènes responsables de maladies rares, de nombreux patients demeurent sans diagnostiques génétiques. L'une des principales raisons de ce problème est le grand nombre de variants de signification inconnue identifiés, où l’impact biologique est peu ou pas connu. Ce mémoire de maîtrise contient trois projets distincts dont l'objectif global est d'augmenter le rendement diagnostique pour les patients atteints de myopathies héréditaires rares. La première étude porte sur trois frères et soeurs atteints d'une dystrophie musculaire non diagnostiquée. Une combinaison de techniques « omic » a été utilisée pour identifier un variant faux-sens dans le gène IARS accompagné d’un déséquilibre allélique spécifique aux tissus musculaires. L’inhibition de iars-1 chez le C. elegans a entraîné une désorganisation progressive du muscle de la paroi corporelle, mais sans perte significative de la motilité. Ainsi, nous avons conclu que iars-1 joue clairement un rôle dans l'organisation des myotubes. La pathogénicité du variant, cependant, nécessite une enquête plus approfondie. La deuxième étude porte sur une femme présentant une myopathie statique congénitale se manifestant par une faiblesse proximale et distale. En utilisant le séquençage de l’ARN, nous avons identifié pour la première fois un profil d'expression génique compatible avec une prédominance des fibres musculaires de type I, focussant l’intérêt sur un variant dans le gène RYR1. La troisième étude englobe une cohorte de vingt-huit patients porteurs de la même mutation RYR1, mais présentant une hétérogénéité clinique significative. Des modèles « knock-in » de C. elegans pour les études deux et trois ont démontrés des changements en transmission synaptique, la durée de vie, la taille corporelle et la locomotion. Ainsi, nous avons conclu que les deux variants identifiés dans RYR1 ont probablement également des conséquences cliniques chez les porteurs humains. En fin de compte, ces études mettent en évidence l'utilité du séquençage de l’ARN en tant qu'outil de diagnostic complémentaire, capable de restreindre la liste de candidats potentiellement pathogéniques, ainsi que le pouvoir du C. elegans en tant que modèles pour des tests rapides et coordonnés de variants candidats. / “Hereditary myopathies” is an umbrella term for rare inherited diseases characterized by muscle weakness and hypotonia with or without muscle atrophy. Individuals with a mild affliction may present with contractures, scoliosis, hyporeflexia or dysmorphic features, while those more severely affected may present cardiac or respiratory involvement that could prove deadly. While traditional DNA-based next-generation sequencing techniques have greatly accelerated discovery of genes causing rare diseases, many patients remain without a known genetic cause. The main reason for this diagnostic shortfall is the vast number of variants of unknown significance identified whose biological functions are unknown. This master’s thesis contains three separate projects with an overarching goal to increase the diagnostic yield of patients with rare hereditary myopathies. The first study focuses on three siblings with an undiagnosed muscular dystrophy. A combination of “omic” techniques were used to identify a missense variant as well as a muscle-specific allelic imbalance in the gene IARS leading to the exclusive expression of the mutant allele. Iars-1 knock-down in C. elegans resulted in progressive disorganization of the body wall muscle but with no significant loss of motility. Thus, we concluded that iars-1 likely plays a role in the organization of myotubes. The pathogenicity of the variant, however, requires further investigation. The second study involves a woman with a congenital static myopathy exhibited as proximal and distal weakness. Using RNA-sequencing, we identified for the first time a gene expression profile consistent with type I fiber predominance in the proband which guided the search for the causative RYR1 variant. The third study encompasses a cohort of twenty-eight patients who carry the same RYR1 mutation but display significant clinical heterogeneity. Knock-in models of C. elegans for both studies demonstrated altered synaptic transmission, lifespan, body size and locomotion. Thus, we concluded that both variants identified in RYR1 likely have consequences for human carriers as well. Ultimately, these studies highlight the utility of RNA-seq as a complimentary diagnostic tool capable of narrowing the search for novel pathogenic mutations as well as the value of C. elegans as models for rapid and coordinated testing of candidate variants.

No / Retinal dystrophies are an overlapping group of genetically heterogeneous conditions resulting from mutations in more than 250 genes. Here we describe five families affected by an adult-onset retinal dystrophy with early macular involvement and associated central visual loss in the third or fourth decade of life. Affected individuals were found to harbor disease-causing variants in DRAM2 (DNA-damage regulated autophagy modulator protein 2). Homozygosity mapping and exome sequencing in a large, consanguineous British family of Pakistani origin revealed a homozygous frameshift variant (c.140delG [p.Gly47Valfs∗3]) in nine affected family members. Sanger sequencing of DRAM2 in 322 unrelated probands with retinal dystrophy revealed one European subject with compound heterozygous DRAM2 changes (c.494G>A [p.Trp165∗] and c.131G>A [p.Ser44Asn]). Inspection of previously generated exome sequencing data in unsolved retinal dystrophy cases identified a homozygous variant in an individual of Indian origin (c.64_66del [p.Ala22del]). Independently, a gene-based case-control association study was conducted via an exome sequencing dataset of 18 phenotypically similar case subjects and 1,917 control subjects. Using a recessive model and a binomial test for rare, presumed biallelic, variants, we found DRAM2 to be the most statistically enriched gene; one subject was a homozygote (c.362A>T [p.His121Leu]) and another a compound heterozygote (c.79T>C [p.Tyr27His] and c.217_225del [p.Val73_Tyr75del]). DRAM2 encodes a transmembrane lysosomal protein thought to play a role in the initiation of autophagy. Immunohistochemical analysis showed DRAM2 localization to photoreceptor inner segments and to the apical surface of retinal pigment epithelial cells where it might be involved in the process of photoreceptor renewal and recycling to preserve visual function.