RESUMO

Limb-girdle muscular dystrophy type 2G/R7 (LGMD2G/R7) is an ultra-rare condition initially identified within the Brazilian population. We aimed to expand clinical and genetic information about this disease, including its worldwide distribution. A multicenter historical cohort study was performed at 13 centers in Brazil in which data from index cases and their affected relatives from consecutive families with LGMD2G/R7 were reviewed from July 2017 to August 2023. Additionally, a systematic literature review was conducted to identify case reports and series of the disease worldwide. Forty-one LGMD2G/R7 cases were described in the Brazilian cohort, being all subjects homozygous for the c.157C>T/(p.Gln53*) variant in TCAP. Survival curves showed that the median disease duration before individuals required walking aids was 21 years. Notably, women exhibited a slower disease progression, requiring walking aids 13 years later than men. LGMD2G/R7 was frequently reported not only in Brazil but also in China and Bulgaria, with 119 cases identified globally, with possible founder effects in the Brazilian, Eastern European, and Asian populations. These findings are pivotal in raising awareness of LGMD2G/R7, understanding its progression, and identifying potential modifiers. This can significantly contribute to the development of future natural history studies and clinical trials for this disease.

Assuntos

RESUMO

Introduction: Myotonic dystrophy type 1 (DM1) is an autosomal dominant neuromuscular disease whose pattern of weakness is predominantly distal. Limb-girdle muscular dystrophy type 2B/R2-dysferlin-related (LGMD2B/R2) is another neuromuscular disease, which presents an autosomal recessive inheritance and is marked by proximal muscle weakness. Even if uncommon, comorbid inherited pathologies must be considered in cases of atypical presentations, especially in those with family history of consanguinity. Case Presentation: Herein, we report the unique case of a patient diagnosed with both DM1 and LGMD2B/R2: a 38-year-old woman in follow-up of DM1 in a neuromuscular disease service presenting prominent proximal weakness. The patient's parents were consanguineous, and creatine kinase levels were elevated. A multi-gene panel test was performed and revealed the diagnosis of LGMD2B/R2. Conclusion: Genetic diseases with atypical presentations should raise the possibility of a second disorder, prompting an appropriate investigation. Overlooking a second diagnosis can implicate in not offering adequate genetic counseling, support, or specific treatment.

RESUMO

Background: Dysferlinopathies represent a group of limb girdle or distal muscular dystrophies with an autosomal-recessive inheritance pattern resulting from the presence of pathogenic variants in the dysferlin gene (DYSF). Objective: In this work, we describe a population from a small city in Brazil carrying the c.5979dupA pathogenic variant of DYSF responsible for limb girdle muscular dystrophy type 2R and distal muscular dystrophy. Methods: Genotyping analyses were performed by qPCR using customized probe complementary to the region with the duplication under analysis in the DYSF. Results: A total of 104 individuals were examined. c.5979dupA was identified in 48 (46.15%) individuals. Twenty-three (22%) were homozygotes, among whom 13 (56.5%) were female. A total of 91.3% (21) of homozygous individuals had a positive family history, and seven (30.4%) reported consanguineous marriages. Twenty-five (24%) individuals were heterozygous (25.8±16 years) for the same variant, among whom 15 (60%) were female. The mean CK level was 697 IU for homozygotes, 140.5 IU for heterozygotes and 176 IU for wild-type homo-zygotes. The weakness distribution pattern showed 17.3% of individuals with a proximal pattern, 13% with a distal pattern and 69.6% with a mixed pattern. Fatigue was present in 15 homozygotes and one heterozygote. Conclusion: The high prevalence of this variant in individuals from this small community can be explained by a possible founder effect associated with historical, geographical and cultural aspects.

RESUMO

INTRODUCTION/AIM: The most common limb girdle muscular dystrophy (LGMD) worldwide is LGMD type R1 (LGMDR1). The aim of this study was to correlate the MRI findings with functional scores and to describe the whole-body MRI (WBMRI) pattern in a LGMDR1 Brazilian cohort. METHODS: LGMDR1 patients under follow-up in three centers were referred for the study. Clinical data were collected and a functional evaluation was performed, consisting of Gardner-Medwin and Walton (GMW) and Brooke scales. All patients underwent a WBMRI study (1.5T) with axial T1 and STIR images. Fifty-one muscles were semiquantitatively assessed regarding fatty infiltration and muscle edema. RESULTS: The study group consisted of 18 patients. The highest fatty infiltration scores involved the serratus anterior, biceps femoris long head, adductor magnus, and lumbar erector spinae. There was a latero-medial and caudo-cranial descending gradient of involvement of the paravertebral muscles, with erector spinae being significantly more affected than the transversospinalis muscles (p < 0.05). A striped appearance that has been dubbed the "pseudocollagen sign" was present in 72% of the patients. There was a positive correlation between the MRI score and GMW (Rho:0.83) and Brooke (Rho:0.53) scores. DISCUSSION: WBMRI in LGMDR1 allows a global patient evaluation including involvement of the paraspinal muscles, usually an underestimated feature in the clinical and imaging study of myopathies. Knowledge of the WBMRI pattern of LGMDR1 involvement can be useful in the diagnostic approach and in future studies to identify the best target muscles to serve as outcome measures in clinical trials.

Assuntos

RESUMO

BACKGROUND: Dysferlinopathy encompasses a group of rare muscular dystrophies caused by recessive mutations in the DYSF gene. The phenotype ranges from asymptomatic elevated serum creatine kinase (hyperCKemia) to selective and progressive involvement of the proximal and/or distal muscles of the limbs. Bohan and Peter criteria are the most widely used for the diagnosis of polymyositis, but they have limitations and can misclassify muscular dystrophies with inflammation as polymyositis. Most dysferlinopathy patients have muscle biopsies with inflammation and thus are vulnerable to misdiagnosis with polymyositis and inappropriate treatment with steroids and immunosuppressors. CASE PRESENTATION: We describe a 14 years-old male patient who was referred for assessment of asymptomatic hyperCKemia (26,372 IU/L). An X-linked dystrophinopathy initially was ruled out by direct genetic testing. Juvenile polymyositis was considered based on muscle biopsy, creatine kinase levels, and electromyography changes. Corticosteroid treatment triggered proximal lower limb muscular weakness, and no full muscular strength recovery was observed after corticosteroid withdrawal. Based on these observations, a limb-girdle muscular dystrophy (LGMD) was suspected, and LGMDR2 was confirmed by whole exome sequencing. CONCLUSION: We report a dysferlinopathy patient who was misdiagnosed with juvenile polymyositis and explore in a literature review how common such misdiagnoses are. With diagnosis based only on routine clinicopathological examinations, distinguishing an inflammatory myopathy from dysferlinopathy is quite difficult. We suggest that before establishing a diagnosis of "definite" or "probable" juvenile polymyositis, according to Bohan and Peter or current ACR/EULAR criteria, a muscular dystrophy must first be ruled out.

Assuntos

RESUMO

We report the anesthetic management with combined spinal-epidural in a patient with limb-girdle muscular dystrophy type 2A, submitted to abdominoplasty and liposuction. The patient had onset of symptoms at 8 years old, diagnosed by muscular biopsy, presenting muscle weakness in the scapular and pelvic girdles, with reduced mobility. We performed monitorization with noninvasive blood pressure, oximeter, thermometer, and electrocardiogram. In the postoperative period, she showed no clinical signs of rhabdomyolysis, myotonia, or adverse effects, maintaining hemodynamic stability. The anesthesia technique allowed spontaneous ventilation, monitoring of clinical parameters close to physiological conditions and used smaller doses of medication, reducing related risks.

Assuntos

RESUMO

RESUMEN La distrofia muscular de cinturas de las extremidades (LGMD, por sus siglas en inglés) incluye varios trastornos con etiologías heterogéneas. Se heredan en patrón autosómico recesivo o autosómico dominante y constituyen la cuarta causa genética más común de debilidad muscular, reportando una prevalencia de 1 en 20,000. Las manifestaciones clínicas son inespecíficas, pueden presentarse desde la primera infancia hasta la edad adulta, dependiendo del subtipo de la enfermedad y de la proteína afectada. El diagnóstico inicial se realiza mediante pruebas genéticas antes de obtener una biopsia muscular. Hasta la actualidad no hay tratamientos que modifiquen la evolución de la enfermedad. El propósito de la terapia es conservar la independencia funcional y tratar las complicaciones asociadas, manteniendo al máximo la calidad de vida.A continuación se reporta el caso de un paciente pediátrico, residente en Quito, Ecuador sin antecedentes patológicos ni familiares previos, con alteración de la motricidad fina progresiva dado por trastorno motor en manos, dedos en flexión, hipotrofia de eminencias tenar e hipotenar y atrofia de interóseos de manos, se realizan estudios en relación a neuropatía periférica distal con afectación de sensibilidad bilateral y simétrica, encontrando como única variante, cambios electromiográficos: polineuropatía crónica, sensitiva y motora de predominio axonal, (desmielinizante en menor grado), de grado marcado presumi-blemente de etiología hereditaria. El diagnostico final lo determinó estudio genético con mutación del gen TTN en relación con: Distrofia muscular de cinturas, tipo 2J (CINTURA ESCAPULAR DE PREDOMINIO DISTAL).

ABSTRACT Limb girdle muscular dystrophy (LGMD) includes several disorders with heterogeneous etiologies. They are inherited in an autosomal recessive or autosomal dominant pattern and constitute the fourth most common genetic cause of muscle weakness, reporting a prevalence of 1 in 20,000. The clinical manifestations are nonspecific, can begin from early childhood to adulthood depending on the subtype of the disease and the protein affected. The initial diagnosis is made by genetic testing before obtaining a muscle biopsy. To date there are no treatments that modify the evolution of the disease. The purpose of therapy is to preserve functional independence and treat associated complications, maintaining quality of life as much as possible.The following is the case of a pediatric patient, resident in Quito, Ecuador with no prior family or pathological history, with progressive fine motor disorder due to motor disorder in the hands, flexed fingers, hypotrophy of tenar and hypothenar eminences, and atrophy of interosseous hands, studies are performed in relation to distal peripheral neuropathy with bilateral and symmetrical sensitivity involvement, finding electromyographic changes as the only variant: chronic, sensitive and motor polyneuropathy with axonal predominance (demyelinating to a lesser degree), of marked degree presumably of hereditary etiology. The final diagnosis was determined by a genetic study with a mutation of the TTN gene in relation to: Girdle Muscular dystrophy, type 2J (DISTAL PREDOMINANT SCAPULAR GIRDLE).

Assuntos

RESUMO

Dysferlin is a sarcolemmal muscle protein associated with the processes of membrane repair, trafficking, and fusion of intracellular vesicles and muscle regeneration. Mutations in the DYSF gene cause clinically distinct forms of muscular dystrophies. The dysferlin-deficient SJL/J mouse model presents a reduction of 85% of the protein but shows mild weakness and discrete histopathological alterations. To study the effect of dysferlin deficiency in the muscle regenerative process, we used a model of electrical injury by electroporation to induce muscle degeneration/regeneration in the SJL/J mouse. The relative expression of the genes Pax7, MyoD, Myf5, and Myog was accompanied by the histopathological evaluation during muscle recovery at different time points after injury. We also investigated the effects of dysferlin deficiency in the expression of genes encoding FAM65B and HDAC6 proteins, recently described as forming a tricomplex with dysferlin at the beginning of myoblast differentiation. We observed an altered time course through the process of degeneration and regeneration in dysferlin-deficient mice, with remarkable regenerative capacity characterized by a faster and effective response in the first days after injury, as compared to the WT mice. Also, dysferlin deficiency seems to significantly alter the gene expression of Fam65b and Hdac6 during regeneration, since higher levels of expression of both genes were observed in dysferlin-deficient mice. These results need further attention to define their relevance in the disease mechanism.

Assuntos

RESUMO

A Distrofia Muscular de Cinturas (DMC) possui herança autossômica dominante ou recessiva e caracteriza-se por paresia progressiva que induz à deterioração funcional e dificuldades no desempenho de atividades cotidianas. O objetivo do presente estudo foi analisar a evolução funcional de indivíduos com diagnóstico de DMC de uma mesma família. Nove indivíduos foram avaliados por um questionário para identificação do parentesco, idade de inicio dos primeiros sintomas e queixas principais, e pelas Escalas de Vignos (EV) e Hammersmith (EMFH). O projeto foi aprovado pelo CEP/UFVJM, protocolo nº061/12. A idade média foi de 33 ± 8.1 anos, com seis indivíduos sendo do sexo masculino, a idade de aparecimento dos primeiros sintomas foi aos 9± 2,83 anos e os sintomas iniciais mais frequentes foram dificuldade de correr, quedas e marcha equina. Os sujeitos pontuaram 4, 6 e 7 na EV e no exame físico verificou-se acometimento principalmente dos membros inferiores. Foi encontrado correlação negativa entre idade dos sujeitos e escore na EMFH (r2=-0,839) e entre pontuação na EV e EMFH (r2 =-0,819), e correlação positiva entre EV e uso de dispositivos (r2=0,866). Nossos achados sugerem que a mesma patologia diagnosticada em indivíduos de uma mesma família apresenta repercussões funcionais diferentes. O aspecto ambiente deve ser levado em consideração ao avaliar a funcionalidade desses indivíduos uma vez que, independente do diagnóstico em comum, da idade, e limitações físicas, os indivíduos apresentaram adaptações particulares com objetivo de manutenção do seu deslocamento de acordo com as características do ambiente em que vive.(AU)

Limb Girdle Muscular Dystrophy (LGMD) is an autosomal-dominant or recessive hereditary disease. Progressive muscular weakness leads to functional damage and difficulty to perform activities of daily life. The present study aimed to analyze the functional evolution of LGMD individuals of the same family. Nine individuals were assessed using a questionnaire (to identify their relationship, age of onset of the first signs of the disease and main complaints) and by Vignos and Hammersmith Scales. Projetct was aproved by Ethics Committee of UFVJM, protocol nº061/12. Mean age was 33±8.1 years old, six male, mean age of onset of the first signs was 9± 2,83 years old and the most frequent signs were difficulty to run, falls and gait with ankle on plantar flexion. Subjects scored 4, 6 and 7 on Vignos Scale and on physical exam, lower limbs were the most affected. Negative correlation between age and Hammermith scale (r 2=-0,839), Vignos and Hammersmith Scale (r2=-0,819) were found. Positive correlation between Vignos Scale and use of assistive devices (r2=0,866). Our finds suggest that the same disease in individuals of the same family leads to different functional impairment. The environmental aspect should be considered when assessing functionality of individuals with LGMD once although they present the same diagnosis, they present particular adaptations with the aim of maintain displacement according to characteristics of the environment where they live.(AU)

Assuntos

RESUMO

BACKGROUND: Limb girdle muscular dystrophy type 2G (LGMD2G) is a subtype of autosomal recessive muscular dystrophy caused by mutations in the telethonin gene. There are few LGMD2G patients worldwide reported, and this is the first description associated with early tibialis anterior sparing on muscle image and myopathic-neurogenic motor unit potentials. CASE PRESENTATION: Here we report a 31 years old caucasian male patient with progressive gait disturbance, and severe lower limb proximal weakness since the age of 20 years, associated with subtle facial muscle weakness. Computed tomography demonstrated soleus, medial gastrocnemius, and diffuse thigh muscles involvement with tibialis anterior sparing. Electromyography disclosed both neurogenic and myopathic motor unit potentials. Muscle biopsy demonstrated large groups of atrophic and hypertrophic fibers, frequent fibers with intracytoplasmic rimmed vacuoles full of autophagic membrane and sarcoplasmic debris, and a total deficiency of telethonin. Molecular investigation identified the common homozygous c.157C > T in the TCAP gene. CONCLUSION: This report expands the phenotypic variability of telethoninopathy/ LGMD2G, including: 1) mixed neurogenic and myopathic motor unit potentials, 2) facial weakness, and 3) tibialis anterior sparing. Appropriate diagnosis in these cases is important for genetic counseling and prognosis.

RESUMO

Patients with sarcoglycanopathies, which comprise four subtypes of autosomal recessive limb-girdle muscular dystrophies, usually present with progressive weakness leading to early loss of ambulation and premature death, and no effective treatment is currently available. Objective To present clinical aspects and outcomes of six children with sarcoglycanopathies treated with steroids for at least one year. Method Patient files were retrospectively analyzed for steroid use. Results Stabilization of muscle strength was noted in one patient, a slight improvement in two, and a slight worsening in three. In addition, variable responses of forced vital capacity and cardiac function were observed. Conclusions No overt clinical improvement was observed in patients with sarcoglycanopathies under steroid therapy. Prospective controlled studies including a larger number of patients are necessary to determine the effects of steroids for sarcoglycanopathies. .

Pacientes com sarcoglicanopatias, que compreendem quatro subtipos de distrofias musculares de cinturas autossômicas recessivas, geralmente apresentam fraqueza progressiva, levando à perda precoce da deambulação e morte prematura, e não há tratamento eficaz disponível até o momento. Objetivo Descrever os aspectos clínicos e a evolução de seis crianças com sarcoglicanopatias tratados com corticosteróides por pelo menos um ano. Método Prontuários dos pacientes foram analisados retrospectivamente. Resultados Estabilização da força muscular foi observada em um paciente, uma ligeira melhora em dois, e um ligeiro agravamento em três. Além disso, foram observadas respostas variáveis de capacidade vital forçada e da função cardíaca. Conclusões Não houve melhora clínica evidente em pacientes com sarcoglicanopatias sob terapia com corticosteróides. Estudos prospectivos controlados incluindo maior número de pacientes são necessários para determinar os efeitos dos corticosteróides para sarcoglicanopatias. .

Assuntos

RESUMO

INTRODUCTION: DNAJB6 mutations cause an autosomal dominant myopathy that can manifest as limb-girdle muscular dystrophy (LGMD1D/1E) or distal-predominant myopathy. In the majority of patients this myopathy manifests in adulthood and shows vacuolar changes on muscle biopsy. METHODS: Clinical, electrophysiological, pathological, and molecular findings are reported. RESULTS: We report a 56-year-old woman, who, like 3 other family members, became symptomatic in childhood with slowly progressive limb-girdle muscle weakness, normal serum creatine kinase (CK) values, and myopathic electromyographic findings. Muscle biopsy showed vacuolar changes and congophilic inclusions, and molecular analysis revealed a pathogenic mutation in the DNAJB6 gene. Differences and similarities with previously described cases are assessed. CONCLUSIONS: Childhood-onset of DNAJB6 myopathy is more frequent than previously believed; congophilic inclusions may be present in the muscle of these patients.

Assuntos