Brazilian version of the Hammersmith Functional Motor Scale Expanded: cross-cultural adaptation and validation.

BACKGROUND: The Hammersmith Functional Motor Scale Expanded (HFMSE) has been widely used to assess the motor function of patients with spinal muscular atrophy (SMA) older than 2 years, with the ability to sit and/or walk. OBJECTIVE: To translate, cross-culturally adapt and validate the HFMSE to Brazilian Portuguese. METHODS: The translation process and cross-cultural adaptation followed international guidelines recommendations. The reliability and applicability of the Brazilian version consisted of the application of the HFMSE (in Brazilian Portuguese) to 20 patients with types 2 and 3 SMA. Two examiners assessed the participants for interrater reliability, through the analysis of Kappa reliability agreement (k) and intraclass correlation coefficient (ICC). RESULTS: The HFMSE was successfully translated and cross culturally adapted to Brazilian Portuguese. Twenty participants with types 2 and 3 SMA were enrolled in the study (type 2 = 6; type 3 = 14). The ICC for the total score showed very high reliability (ICC =1.00), and the reliability of each of the items individually was considered excellent (Kappa > 0.80). CONCLUSION: The Brazilian version of the HFMSE proved to be valid and reliable for the evaluation of SMA patients older than 2 years with the ability to sit and/or walk.

ANTECEDENTES: A Hammersmith Functional Motor Scale Expanded (HFMSE) tem sido amplamente utilizada para avaliar a função motora de pacientes com atrofia muscular espinhal (AME) maiores de dois anos, com capacidade de sentar e/ou andar. OBJETIVO: Traduzir, adaptar transculturalmente e validar a HFMSE para o português brasileiro. MéTODOS: A tradução e a adaptação transcultural seguiram as diretrizes internacionais. A confiabilidade e a aplicabilidade da versão brasileira consistiram na aplicação da HFMSE (em português brasileiro) em 20 pacientes com AME tipos 2 e 3. Dois examinadores avaliaram os participantes quanto à confiabilidade interexaminadores, por meio da análise da concordância de confiabilidade Kappa (k) e do coeficiente de correlação intraclasse (intraclass correlation coefficient [ICC]). RESULTADOS: O processo de tradução e adaptação transcultural da HFMSE para o português brasileiro foi concluído com sucesso. Vinte participantes com AME tipos 2 e 3 foram incluídos no estudo (tipo 2 = 6; tipo 3 = 14). O ICC para o escore total apresentou confiabilidade alta (ICC = 1.00) e a confiabilidade de cada um dos itens individualmente foi considerada excelente (K > 0,80). CONCLUSãO: A HFMSE (PT-BR) mostrou-se válida e confiável para a avaliação de pacientes com AME, com mais de dois anos de idade e com capacidade de sentar-se independentemente e/ou andar.

Consensus from the Brazilian Academy of Neurology for the diagnosis, genetic counseling, and use of disease-modifying therapies in 5q spinal muscular atrophy.

Spinal muscular atrophy linked to chromosome 5 (SMA-5q) is an autosomal recessive genetic disease caused by mutations in the SMN1. SMA-5q is characterized by progressive degeneration of the spinal cord and bulbar motor neurons, causing severe motor and respiratory impairment with reduced survival, especially in its more severe clinical forms. In recent years, highly effective disease-modifying therapies have emerged, either acting by regulating the splicing of exon 7 of the SMN2 gene or adding a copy of the SMN1 gene through gene therapy, providing a drastic change in the natural history of the disease. In this way, developing therapeutic guides and expert consensus becomes essential to direct the use of these therapies in clinical practice. This consensus, prepared by Brazilian experts, aimed to review the main available disease-modifying therapies, critically analyze the results of clinical studies, and provide recommendations for their use in clinical practice for patients with SMA-5q. This consensus also addresses aspects related to diagnosis, genetic counseling, and follow-up of patients under drug treatment. Thus, this consensus provides valuable information regarding the current management of SMA-5q, helping therapeutic decisions in clinical practice and promoting additional gains in outcomes.

Atrofia muscular espinhal ligada ao cromossomo 5 (AME-5q) é uma doença genética de herança autossômica recessiva causada por mutações no gene SMN1. A AME-5q cursa com degeneração progressiva dos motoneurônios medulares e bulbares, acarretando grave comprometimento motor e respiratório com redução da sobrevida, especialmente nas suas formas clínicas mais graves. Nos últimos anos, terapias modificadoras da doença altamente eficazes, ou que atuam regulando o splicing do exon 7 do gene SMN2 ou adicionando uma cópia do gene SMN1 via terapia gênica, têm surgido, proporcionando uma mudança drástica na história natural da doença. Dessa forma, o desenvolvimento de guias terapêuticos e de consensos de especialistas torna-se importante no sentido de direcionar o uso dessas terapias na prática clínica. Este consenso, preparado por especialistas brasileiros, teve como objetivos revisar as principais terapias modificadoras de doença disponíveis, analisar criticamente os resultados dos estudos clínicos dessas terapias e prover recomendações para seu uso na prática clínica para pacientes com AME-5q. Aspectos relativos ao diagnóstico, aconselhamento genético e seguimento dos pacientes em uso das terapias também são abordados nesse consenso. Assim, esse consenso promove valiosas informações a respeito do manejo atual da AME-5q auxiliando decisões terapêuticas na prática clínica e promovendo ganhos adicionais nos desfechos finais.

Consensus from the Brazilian Academy of Neurology for the diagnosis, genetic counseling, and use of disease-modifying therapies in 5q spinal muscular atrophy / Consenso da Academia Brasileira de Neurologia para diagnóstico, aconselhamento genético e uso de terapias modificadoras na atrofia muscular espinhal 5q

Abstract Spinal muscular atrophy linked to chromosome 5 (SMA-5q) is an autosomal recessive genetic disease caused by mutations in the SMN1. SMA-5q is characterized by progressive degeneration of the spinal cord and bulbar motor neurons, causing severe motor and respiratory impairment with reduced survival, especially in its more severe clinical forms. In recent years, highly effective disease-modifying therapies have emerged, either acting by regulating the splicing of exon 7 of the SMN2 gene or adding a copy of the SMN1 gene through gene therapy, providing a drastic change in the natural history of the disease. In this way, developing therapeutic guides and expert consensus becomes essential to direct the use of these therapies in clinical practice. This consensus, prepared by Brazilian experts, aimed to review the main available disease-modifying therapies, critically analyze the results of clinical studies, and provide recommendations for their use in clinical practice for patients with SMA-5q. This consensus also addresses aspects related to diagnosis, genetic counseling, and follow-up of patients under drug treatment. Thus, this consensus provides valuable information regarding the current management of SMA-5q, helping therapeutic decisions in clinical practice and promoting additional gains in outcomes.

Resumo Atrofia muscular espinhal ligada ao cromossomo 5 (AME-5q) é uma doença genética de herança autossômica recessiva causada por mutações no gene SMN1. A AME-5q cursa com degeneração progressiva dos motoneurônios medulares e bulbares, acarretando grave comprometimento motor e respiratório com redução da sobrevida, especialmente nas suas formas clínicas mais graves. Nos últimos anos, terapias modificadoras da doença altamente eficazes, ou que atuam regulando o splicing do exon 7 do gene SMN2 ou adicionando uma cópia do gene SMN1 via terapia gênica, têm surgido, proporcionando uma mudança drástica na história natural da doença. Dessa forma, o desenvolvimento de guias terapêuticos e de consensos de especialistas torna-se importante no sentido de direcionar o uso dessas terapias na prática clínica. Este consenso, preparado por especialistas brasileiros, teve como objetivos revisar as principais terapias modificadoras de doença disponíveis, analisar criticamente os resultados dos estudos clínicos dessas terapias e prover recomendações para seu uso na prática clínica para pacientes com AME-5q. Aspectos relativos ao diagnóstico, aconselhamento genético e seguimento dos pacientes em uso das terapias também são abordados nesse consenso. Assim, esse consenso promove valiosas informações a respeito do manejo atual da AME-5q auxiliando decisões terapêuticas na prática clínica e promovendo ganhos adicionais nos desfechos finais.

Brazilian version of the Hammersmith Functional Motor Scale Expanded: cross-cultural adaptation and validation / Versão brasileira da Hammersmith Functional Motor Scale Expanded: adaptação transcultural e validação

Abstract Background The Hammersmith Functional Motor Scale Expanded (HFMSE) has been widely used to assess the motor function of patients with spinal muscular atrophy (SMA) older than 2 years, with the ability to sit and/or walk. Objective To translate, cross-culturally adapt and validate the HFMSE to Brazilian Portuguese. Methods The translation process and cross-cultural adaptation followed international guidelines recommendations. The reliability and applicability of the Brazilian version consisted of the application of the HFMSE (in Brazilian Portuguese) to 20 patients with types 2 and 3 SMA. Two examiners assessed the participants for interrater reliability, through the analysis of Kappa reliability agreement (k) and intraclass correlation coefficient (ICC). Results The HFMSE was successfully translated and cross culturally adapted to Brazilian Portuguese. Twenty participants with types 2 and 3 SMA were enrolled in the study (type 2 = 6; type 3 = 14). The ICC for the total score showed very high reliability (ICC =1.00), and the reliability of each of the items individually was considered excellent (Kappa > 0.80). Conclusion The Brazilian version of the HFMSE proved to be valid and reliable for the evaluation of SMA patients older than 2 years with the ability to sit and/or walk.

Resumo Antecedentes A Hammersmith Functional Motor Scale Expanded (HFMSE) tem sido amplamente utilizada para avaliar a função motora de pacientes com atrofia muscular espinhal (AME) maiores de dois anos, com capacidade de sentar e/ou andar. Objetivo Traduzir, adaptar transculturalmente e validar a HFMSE para o português brasileiro. Métodos A tradução e a adaptação transcultural seguiram as diretrizes internacionais. A confiabilidade e a aplicabilidade da versão brasileira consistiram na aplicação da HFMSE (em português brasileiro) em 20 pacientes com AME tipos 2 e 3. Dois examinadores avaliaram os participantes quanto à confiabilidade interexaminadores, por meio da análise da concordância de confiabilidade Kappa (k) e do coeficiente de correlação intraclasse (intraclass correlation coefficient [ICC]). Resultados O processo de tradução e adaptação transcultural da HFMSE para o português brasileiro foi concluído com sucesso. Vinte participantes com AME tipos 2 e 3 foram incluídos no estudo (tipo 2 = 6; tipo 3 = 14). O ICC para o escore total apresentou confiabilidade alta (ICC = 1.00) e a confiabilidade de cada um dos itens individualmente foi considerada excelente (K > 0,80). Conclusão A HFMSE (PT-BR) mostrou-se válida e confiável para a avaliação de pacientes com AME, com mais de dois anos de idade e com capacidade de sentar-se independentemente e/ou andar.

Clinical management and diagnosis of CLN2 disease: consensus of the Brazilian experts group.

Neuronal ceroid lipofuscinosis type 2 (CLN2) is a rare neurodegenerative genetic disease that affects children in early life. Its classic form is rapidly progressive, leading to death within the first 10 years. The urge for earlier diagnosis increases with the availability of enzyme replacement therapy. A panel of nine Brazilian child neurologists combined their expertise in CLN2 with evidence from the medical literature to establish a consensus to manage this disease in Brazil. They voted 92 questions including diagnosis, clinical manifestations, and treatment of the disease, considering the access to healthcare in this country. Clinicians should suspect CLN2 disease in any child, from 2 to 4 years old, with language delay and epilepsy. Even though the classic form is the most prevalent, atypical cases with different phenotypes can be found. Electroencephalogram, magnetic resonance imaging, molecular and biochemical testing are the main tools to investigate and confirm the diagnosis. However, we have limited access to molecular testing in Brazil, and rely on the support from the pharmaceutical industry. The management of CLN2 should involve a multidisciplinary team and focus on the quality of life of patients and on family support. Enzyme replacement therapy with Cerliponase α is an innovative treatment approved in Brazil since 2018; it delays functional decline and provides quality of life. Given the difficulties for the diagnosis and treatment of rare diseases in our public health system, the early diagnosis of CLN2 needs improvement as enzyme replacement therapy is available and modifies the prognosis of patients.

Lipofuscinose ceróide neuronal (CLN2) é uma doença genética neurodegenerativa rara que afeta crianças nos primeiros anos de vida. A sua forma clássica é rapidamente progressiva, levando à morte nos primeiros 10 anos. A necessidade de um diagnóstico precoce aumenta com a disponibilidade do tratamento de terapia enzimática. Um painel de nove neurologistas infantis brasileiros combinou sua experiência em CLN2 com evidências da literatura médica para estabelecer um consenso no manejo desta doença no Brasil. Eles votaram 92 questões abordando diagnóstico, manifestações clínicas e tratamento, considerando o acesso à saúde no Brasil. Deve-se suspeitar de CLN2 em qualquer criança de 2 a 4 anos de idade que apresente atraso de linguagem e epilepsia. Apesar da forma clássica ser a mais prevalente, podem ser encontrados casos atípicos com diferentes fenótipos. Eletroencefalograma, ressonância magnética, testes moleculares e bioquímicos são as principais ferramentas para investigar e confirmar o diagnóstico. No entanto, o acesso aos testes moleculares é limitado no Brasil, necessitando contar com o apoio da indústria farmacêutica. O manejo da CLN2 deve envolver uma equipe multidisciplinar e focar na qualidade de vida dos pacientes e no apoio familiar. A terapia de reposição enzimática com Cerliponase alfa é um tratamento inovador aprovado no Brasil desde 2018; ele retarda o declínio funcional e proporciona qualidade de vida. Diante das dificuldades para o diagnóstico e tratamento de doenças raras em nosso sistema público de saúde, o diagnóstico precoce de CLN2 precisa de melhorias pois a terapia de reposição enzimática está disponível e modifica o prognóstico dos pacientes.

Update of the Brazilian consensus recommendations on Duchenne muscular dystrophy.

In the last few decades, there have been considerable improvements in the diagnosis and care of Duchenne muscular dystrophy (DMD), the most common childhood muscular dystrophy. International guidelines have been published and recently reviewed. A group of Brazilian experts has developed a standard of care based on a literature review with evidence-based graded recommendations in a two-part publication. Implementing best practice management has helped change the natural history of this chronic progressive disorder, in which the life expectancy for children of the male sex in the past used to be very limited. Since the previous publication, diagnosis, steroid treatment, rehabilitation, and systemic care have gained more significant insights with new original work in certain fields. Furthermore, the development of new drugs is ongoing, and some interventions have been approved for use in certain countries. Therefore, we have identified the need to review the previous care recommendations for Brazilian patients with DMD. Our objective was to create an evidence-based document that is an update on our previous consensus on those topics.

Nas últimas décadas, houve progressos significativos no diagnóstico e no tratamento da distrofia muscular de Duchenne (DMD), considerada a distrofia muscular mais comum na infância. Diretrizes internacionais foram publicadas e revisadas recentemente. Um grupo de especialistas brasileiros desenvolveu um padrão de atendimento baseado em revisão de literatura, com recomendações graduadas pautadas em evidências compiladas em uma publicação dividida em duas partes. A implementação de melhores práticas de manejo ajudou a modificar a história natural desta doença crônica, progressiva, que, no passado, oferecia uma expectativa de vida muito limitada para crianças do sexo masculino. Desde a publicação desse consenso anterior, o diagnóstico, o tratamento com esteroides, a reabilitação e os cuidados sistêmicos ganharam novas possibilidades a partir da divulgação dos resultados de trabalhos originais em algumas dessas áreas. Além disso, as pesquisas e o desenvolvimento de novos fármacos estão em andamento, e algumas intervenções já foram aprovadas para uso em determinados países. Nesse contexto, identificamos a necessidade de rever as recomendações anteriores sobre o manejo dos pacientes brasileiros com DMD. Nosso objetivo principal foi elaborar uma atualização baseada em evidências sobre esses tópicos do consenso.

Clinical management and diagnosis of CLN2 disease: consensus of the Brazilian experts group / Manejo clínico e diagnóstico da doença CLN2: consenso do grupo de especialistas brasileiros

Abstract Neuronal ceroid lipofuscinosis type 2 (CLN2) is a rare neurodegenerative genetic disease that affects children in early life. Its classic form is rapidly progressive, leading to death within the first 10 years. The urge for earlier diagnosis increases with the availability of enzyme replacement therapy. A panel of nine Brazilian child neurologists combined their expertise in CLN2 with evidence from the medical literature to establish a consensus to manage this disease in Brazil. They voted 92 questions including diagnosis, clinical manifestations, and treatment of the disease, considering the access to healthcare in this country. Clinicians should suspect CLN2 disease in any child, from 2 to 4 years old, with language delay and epilepsy. Even though the classic form is the most prevalent, atypical cases with different phenotypes can be found. Electroencephalogram, magnetic resonance imaging, molecular and biochemical testing are the main tools to investigateand confirm the diagnosis. However, we have limited access to molecular testing in Brazil, and rely on the support from the pharmaceutical industry. The management of CLN2 should involve a multidisciplinary team and focus on the quality of life of patients and on family support. Enzyme replacement therapy with Cerliponase α is an innovative treatment approved in Brazil since 2018; it delays functional decline and provides quality of life. Given the difficulties for the diagnosis and treatment of rare diseases in our public health system, the early diagnosis of CLN2 needs improvement as enzyme replacement therapy is available and modifies the prognosis of patients.

Resumo Lipofuscinose ceróide neuronal (CLN2) é uma doença genética neurodegenerativa rara que afeta crianças nos primeiros anos de vida. A sua forma clássica é rapidamente progressiva, levando à morte nos primeiros 10 anos. A necessidade de um diagnóstico precoce aumenta com a disponibilidade do tratamento de terapia enzimática. Um painel de nove neurologistas infantis brasileiros combinou sua experiência em CLN2 com evidências da literatura médica para estabelecer um consenso no manejo desta doença no Brasil. Eles votaram 92 questões abordando diagnóstico, manifestações clínicas e tratamento, considerando o acesso à saúde no Brasil. Deve-se suspeitar de CLN2 em qualquer criança de 2 a 4 anos de idade que apresente atraso de linguagem e epilepsia. Apesar da forma clássica ser a mais prevalente, podem ser encontrados casos atípicos com diferentes fenótipos. Eletroencefalograma, ressonância magnética, testes moleculares e bioquímicos são as principais ferramentas para investigar e confirmar o diagnóstico. No entanto, o acesso aos testes moleculares é limitado no Brasil, necessitando contar com o apoio da indústria farmacêutica. O manejo da CLN2 deve envolver uma equipe multidisciplinar e focar na qualidade de vida dos pacientes e no apoio familiar. A terapia de reposição enzimática com Cerliponase alfa é um tratamento inovador aprovado no Brasil desde 2018; ele retarda o declínio funcional e proporciona qualidade de vida. Diante das dificuldades para o diagnóstico e tratamento de doenças raras em nosso sistema público de saúde, o diagnóstico precoce de CLN2 precisa de melhorias pois a terapia de reposição enzimática está disponível e modifica o prognóstico dos pacientes.

Update of the Brazilian consensus recommendations on Duchenne muscular dystrophy / Atualização das recomendações do consenso brasileiro para distrofia muscular de Duchenne

Abstract In the last few decades, there have been considerable improvements in the diagnosis and care of Duchenne muscular dystrophy (DMD), the most common childhood muscular dystrophy. International guidelines have been published and recently reviewed. A group of Brazilian experts has developed a standard of care based on a literature review with evidence-based graded recommendations in a two-part publication. Implementing best practice management has helped change the natural history of this chronic progressive disorder, in which the life expectancy for children of the male sex in the past used to be very limited. Since the previous publication, diagnosis, steroid treatment, rehabilitation, and systemic care have gained more significant insights with new original work in certain fields. Furthermore, the development of new drugs is ongoing, and some interventions have been approved for use in certain countries. Therefore, we have identified the need to review the previous care recommendations for Brazilian patients with DMD. Our objective was to create an evidence-based document that is an update on our previous consensus on those topics.

Resumo Nas últimas décadas, houve progressos significativos no diagnóstico e no tratamento da distrofia muscular de Duchenne (DMD), considerada a distrofia muscular mais comum na infância. Diretrizes internacionais foram publicadas e revisadas recentemente. Um grupo de especialistas brasileiros desenvolveu um padrão de atendimento baseado em revisão de literatura, com recomendações graduadas pautadas em evidências compiladas em uma publicação dividida em duas partes. A implementação de melhores práticas de manejo ajudou a modificar a história natural desta doença crônica, progressiva, que, no passado, oferecia uma expectativa de vida muito limitada para crianças do sexo masculino. Desde a publicação desse consenso anterior, o diagnóstico, o tratamento com esteroides, a reabilitação e os cuidados sistêmicos ganharam novas possibilidades a partir da divulgação dos resultados de trabalhos originais em algumas dessas áreas. Além disso, as pesquisas e o desenvolvimento de novos fármacos estão em andamento, e algumas intervenções já foram aprovadas para uso em determinados países. Nesse contexto, identificamos a necessidade de rever as recomendações anteriores sobre o manejo dos pacientes brasileiros com DMD. Nosso objetivo principal foi elaborar uma atualização baseada em evidências sobre esses tópicos do consenso.

Nemaline Myopathy in Brazilian Patients: Molecular and Clinical Characterization.

Nemaline myopathy (NM), a structural congenital myopathy, presents a significant clinical and genetic heterogeneity. Here, we compiled molecular and clinical data of 30 Brazilian patients from 25 unrelated families. Next-generation sequencing was able to genetically classify all patients: sixteen families (64%) with mutation in NEB, five (20%) in ACTA1, two (8%) in KLHL40, and one in TPM2 (4%) and TPM3 (4%). In the NEB-related families, 25 different variants, 11 of them novel, were identified; splice site (10/25) and frame shift (9/25) mutations were the most common. Mutation c.24579 G>C was recurrent in three unrelated patients from the same region, suggesting a common ancestor. Clinically, the "typical" form was the more frequent and caused by mutations in the different NM genes. Phenotypic heterogeneity was observed among patients with mutations in the same gene. Respiratory involvement was very common and often out of proportion with limb weakness. Muscle MRI patterns showed variability within the forms and genes, which was related to the severity of the weakness. Considering the high frequency of NEB mutations and the complexity of this gene, NGS tools should be combined with CNV identification, especially in patients with a likely non-identified second mutation.

A Novel SPEG mutation causing congenital myopathy with fiber size disproportion and dilated cardiomyopathy with heart transplantation.

Congenital myopathies are a heterogeneous group of conditions diagnosed based on the clinical presentation, muscle histopathology and genetic defects. Recessive mutations in the SPEG gene have been described in recent years and are primarily associated with centronuclear myopathy with cardiomyopathy. In this report, we describe two Brazilian siblings, aged 13 and 6 years, with a novel homozygous mutation (c.8872 C>T:p.Arg2958Ter) in the SPEG gene leading to a congenital myopathy. In the older sibling, the muscle biopsy showed fiber size disproportion. The mean diameter of type 2 fibers (119 µm) was significantly higher than type 1 (57 µm) (P < 0,001) with a 72% prevalence of type 1 fibers. The patient also had progressive cardiomyopathy treated with heart transplantation. The present report expands the muscle histopathological findings related to mutations in the SPEG gene, including fiber size disproportion without central nuclei. Additionally, this report describes the first case of heart transplantation in a patient with SPEG mutations.

Association of Three Different Mutations in the CLCN1 Gene Modulating the Phenotype in a Consanguineous Family with Myotonia Congenita.

Myotonia congenita is a genetic disease caused by mutations in the CLCN1 gene, which encodes for the major chloride skeletal channel ClC-1, involved in the normal repolarization of muscle action potentials and consequent relaxation of the muscle after contraction. Two allelic forms are recognized, depending on the phenotype and the inheritance pattern: the autosomal dominant Thomsen disease with milder symptoms and the autosomal recessive Becker disorder with a severe phenotype. Before the recent advances of molecular testing, the diagnosis and genetic counseling of families was a challenge due to the large number of mutations in the CLCN1 gene, found both in homozygous or in heterozygous state. Here, we studied a consanguineous family in which three members presented a variable phenotype of myotonia, associated to a combination of three different mutations in the CLCN1 gene. A pathogenic splicing site mutation which causes the skipping of exon 17 was present in homozygosis in one very severely affected son. This mutation was present in compound heterozygosis in the consanguineous parents, but interestingly it was associated to a different second variant in the other allele: c.1453 A > G in the mother and c.1842 G > C in the father. Both displayed variable, but less severe phenotypes than their homozygous son. These results highlight the importance of analyzing the combination of different variants in the same gene in particular in families with patients displaying different phenotypes. This approach may improve the diagnosis, prognosis, and genetic counseling of the involved families.

Dominant or recessive mutations in the RYR1 gene causing central core myopathy in Brazilian patients.

Central Core Disease (CCD) is an inherited neuromuscular disorder characterized by the presence of cores in muscle biopsy. CCD is caused by mutations in the RYR1 gene. This gene encodes the ryanodine receptor 1, which is an intracellular calcium release channel from the sarcoplasmic reticulum to the cytosol in response to depolarization of the plasma membrane. Mutations in this gene are also associated with susceptibility to Malignant Hyperthermia (MHS). In this study, we evaluated 20 families with clinical and histological characteristics of CCD to identify primary mutations in patients, for diagnosis and genetic counseling of the families. We identified variants in the RYR1 gene in 19/20 families. The molecular pathogenicity was confirmed in 16 of them. Most of these variants (22/23) are missense and unique in the families. Two variants were recurrent in two different families. We identified six families with biallelic mutations, five compound heterozygotes with no consanguinity, and one homozygous, with consanguineous parents, resulting in 30% of cases with possible autosomal recessive inheritance. We identified seven novel variants, four of them classified as pathogenic. In one family, we identified two mutations in exon 102, segregating in cis, suggesting an additive effect of two mutations in the same allele. This work highlights the importance of using Next-Generation Sequencing technology for the molecular diagnosis of genetic diseases when a very large gene is involved, associated to a broad distribution of the mutations along it. These data also influence the prevention through adequate genetic counseling for the families and cautions against malignant hyperthermia susceptibility.

A novel complex neurological phenotype due to a homozygous mutation in FDX2.

Defects in iron-sulphur [Fe-S] cluster biogenesis are increasingly recognized as causing neurological disease. Mutations in a number of genes that encode proteins involved in mitochondrial [Fe-S] protein assembly lead to complex neurological phenotypes. One class of proteins essential in the early cluster assembly are ferredoxins. FDX2 is ubiquitously expressed and is essential in the de novo formation of [2Fe-2S] clusters in humans. We describe and genetically define a novel complex neurological syndrome identified in two Brazilian families, with a novel homozygous mutation in FDX2. Patients were clinically evaluated, underwent MRI, nerve conduction studies, EMG and muscle biopsy. To define the genetic aetiology, a combination of homozygosity mapping and whole exome sequencing was performed. We identified six patients from two apparently unrelated families with autosomal recessive inheritance of a complex neurological phenotype involving optic atrophy and nystagmus developing by age 3, followed by myopathy and recurrent episodes of cramps, myalgia and muscle weakness in the first or second decade of life. Sensory-motor axonal neuropathy led to progressive distal weakness. MRI disclosed a reversible or partially reversible leukoencephalopathy. Muscle biopsy demonstrated an unusual pattern of regional succinate dehydrogenase and cytochrome c oxidase deficiency with iron accumulation. The phenotype was mapped in both families to the same homozygous missense mutation in FDX2 (c.431C > T, p.P144L). The deleterious effect of the mutation was validated by real-time reverse transcription polymerase chain reaction and western blot analysis, which demonstrated normal expression of FDX2 mRNA but severely reduced expression of FDX2 protein in muscle tissue. This study describes a novel complex neurological phenotype with unusual MRI and muscle biopsy features, conclusively mapped to a mutation in FDX2, which encodes a ubiquitously expressed mitochondrial ferredoxin essential for early [Fe-S] cluster biogenesis.

Brazilian consensus on Duchenne muscular dystrophy. Part 1: diagnosis, steroid therapy and perspectives.

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.

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.

Dual molecular diagnosis contributes to atypical Prader-Willi phenotype in monozygotic twins.

We describe monozygotic twin girls with genetic variation at two separate loci resulting in a blended phenotype of Prader-Willi syndrome and Pitt-Hopkins syndrome. These girls were diagnosed in early infancy with Prader-Willi syndrome, but developed an atypical phenotype, with apparent intellectual deficiency and lack of obesity. Array-comparative genomic hybridization confirmed a de novo paternal deletion of the 15q11.2q13 region and exome sequencing identified a second mutational event in both girls, which was a novel variant c.145+1G>A affecting a TCF4 canonical splicing site inherited from the mosaic mother. RNA studies showed that the variant abolished the donor splicing site, which was accompanied by activation of an alternative non-canonical splicing-site which then predicts a premature stop codon in the following exon. Clinical re-evaluation of the twins indicated that both variants are likely contributing to the more severe phenotypic presentation. Our data show that atypical clinical presentations may actually be the expression of blended clinical phenotypes arising from independent pathogenic events at two loci.

Myocardial Fibrosis Progression in Duchenne and Becker Muscular Dystrophy: A Randomized Clinical Trial.

Importance: In Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD), interventions reducing the progression of myocardial disease could affect survival. Objective: To assess the effect of early angiotensin-converting enzyme (ACE) inhibitor therapy in patients with normal left ventricular function on the progression of myocardial fibrosis (MF) identified on cardiovascular magnetic resonance (CMR). Design, Setting, and Participants: A randomized clinical trial conducted in 2 centers included 76 male patients with DMD or BMD undergoing 2 CMR studies with a 2-year interval for ventricular function and MF assessment. In a non-intent-to-treat trial, 42 patients with MF and normal left ventricular ejection fraction (LVEF) were randomized (1:1) to receive or not receive ACE inhibitor therapy. The study was conducted from June 26, 2009, to June 30, 2012. Data analysis was performed from June 30, 2013, to October 3, 2016. Interventions: Randomization (1:1) to receive or not receive ACE inhibitor therapy. Main Outcomes and Measures: Primary outcome was MF progression from baseline to the 2-year CMR study. Results: Of the 76 male patients included in the study, 70 had DMD (92%) and 6 had BMD (8%); mean (SD) age at baseline was 13.1 (4.4) years. Myocardial fibrosis was present in 55 patients (72%) and LV systolic dysfunction was identified in 13 patients (24%). Myocardial fibrosis at baseline was an independent indicator of lower LVEF at follow-up (coefficient [SE], -0.16 [0.07]; P = .03). Among patients with MF and preserved LVEF (42 [55%]), those randomized (21 patients in each arm) to receive ACE inhibitors demonstrated slower MF progression compared with the untreated group (mean [SD] increase of 3.1% [7.4%] vs 10.0% [6.2%] as a percentage of LV mass; P = .001). In multivariate analysis, ACE inhibitor therapy was an independent indicator of decreased MF progression (coefficient [SE], -4.51 [2.11]; P = .04). Patients with MF noted on CMR had a higher probability of cardiovascular events (event rate, 10 of 55 [18.2%] vs 0 of 21 [0%]; log-rank P = .04). Conclusions and Relevance: In this 2-year, follow-up, randomized clinical trial of patients with Duchenne or Becker muscular dystrophy whose LVEF was preserved and MF was present as determined on CMR, ACE inhibitor therapy was associated with significantly slower progression of MF. The presence of MF was associated with worse patient prognosis. Trial Registration: clinicaltrials.org Identifier: NCT02432885.

High Incidence of Biotinidase Deficiency from a Pilot Newborn Screening Study in Minas Gerais, Brazil.

OBJECTIVE: To assess the incidence of biotinidase deficiency among newborns and their clinical outcome up to one year of age in a large pilot screening study in Minas Gerais, Brazil. METHODS: A prospective cohort study was conducted from September 2007 to June 2008 with heel-prick blood samples collected on filter paper for the purpose of newborn screening. A qualitative colorimetric test was used as the primary screening method. Colorimetric-positive cases were further tested with a serum confirmatory assay. Gene sequencing was performed for eight children suspected with biotinidase deficiency and for some of their parents. Positive cases were daily supplemented with oral biotin and were followed up for approximately six years. RESULTS: Out of 182,891 newborns screened, 129 were suspected of having biotinidase deficiency. Partial deficiency was confirmed in seven children (one was homozygous for p.D543E) and profound deficiency in one child (homozygous p.H485Q). Thus the incidence was one in 22,861 live births (95% confidence interval 1:13,503 to 1:74,454) for profound and partial biotinidase deficiency combined. Two novel mutations were detected: p.A281V and p.E177K. In silico analysis and estimation of the enzyme activity in the children and their parents showed that p.A281V is pathogenic and p.E177K behaves like p.D444H. CONCLUSION: The incidence of biotinidase deficiency in newborn screening in Minas Gerais was higher than several international studies. The sample size should be larger for final conclusions. Oral daily biotin apparently precluded clinical symptoms, but it may have been unnecessary in some newborns.

Clinical and molecular characterization of McArdle's disease in Brazilian patients.

McArdle's disease, a glycogen storage disease type V, is caused by a deficiency of the enzyme myophosphorylase, encoded by the PYGM gene. Worldwide distribution of mutations has revealed interesting data about the prevalence of mutations and population migrations. Currently, more than 100 mutations in the PYGM gene have been described, with some recurrent mutations in the different populations. However, no molecular studies of McArdle's disease were reported in Brazilian patients. Here, we describe the clinical phenotype and genotype of 10 patients from 8 unrelated Brazilian families. Among the 10 patients (3 females, 7 males), eight presented with the typical phenotype, with exercise intolerance, cramps, and myalgia; one patient showed permanent muscle weakness; and one patient showed a mild phenotype. Molecular analysis identified 5 different mutations in the 8 families, both in homozygosis or compound heterozygosis state. Four of them had already been described (p.R50X, p.T692kfs30, p.K609K, and p.G455R), and one, pI513V, is a novel heterozygous mutation. The common nonsense p.R50X mutation was found in 6 of the 8 families, being therefore the commonest mutation in the Brazilian population as well. Other mutations previously reported in European patients were also found in the patients in this study, which was expected considering the European ancestry of the Brazilian population.