ABSTRACT
Abstract Duchenne muscular dystrophy (DMD) usually affects men. However, women are also affected in rare instances. Approximately 8% of female DMD carriers have muscle weakness and cardiomyopathy. The early identification of functional and motor impairments can support clinical decision making. Objective: To investigate the motor and functional impairments of 10 female patients with dystrophinopathy diagnosed with clinical, pathological, genetic and immunohistochemical studies. Methods: A descriptive study of a sample of symptomatic female carriers of DMD mutations. The studied variables were muscular strength and functional performance. Results: The prevalence was 10/118 (8.4%) symptomatic female carriers. Deletions were found in seven patients. The age of onset of symptoms in female carriers of DMD was quite variable. Pseudohypertrophy of calf muscles, muscular weakness, compensatory movements and longer timed performance on functional tasks were observed in most of the cases. Differently from males with DMD, seven female patients showed asymmetrical muscular weakness. The asymmetric presentation of muscle weakness was frequent and affected posture and functionality in some cases. The functional performance presents greater number of compensatory movements. Time of execution of activities was not a good biomarker of functionality for this population, because it does not change in the same proportion as the number of movement compensations. Conclusion: Clinical manifestation of asymmetrical muscle weakness and compensatory movements, or both can be found in female carriers of DMD mutations, which can adversely affect posture and functional performance of these patients.
Resumo A distrofia muscular de Duchenne (DMD) geralmente afeta indivíduos do sexo masculino. No entanto, mulheres também são acometidas em casos raros. Aproximadamente 8% das portadoras de DMD têm fraqueza muscular ou cardiomiopatia. A identificação precoce das alterações funcionais e motoras pode alterar a tomada de decisão clínica. Objetivo: Investigar as deficiências motoras e funcionais de 10 pacientes do sexo feminino com distrofinopatia diagnosticada por estudos clínicos, patológicos, genéticos e imuno-histoquímicos. Método: Estudo descritivo de uma amostra de portadoras sintomáticas de mutações DMD. As variáveis estudadas foram força muscular e desempenho funcional. Resultados: A prevalência foi de 10/118 (8,4%) de portadoras sintomáticas de DMD. Foram encontradas deleções em sete pacientes. A idade de início dos sintomas em portadoras de DMD foi variável. Pseudo-hipertrofia de panturrilhas, movimentos compensatórios, fraqueza muscular e aumento no tempo de execução de tarefas funcionais foram observados na maioria dos casos. Diferentemente dos homens com DMD, sete pacientes apresentaram fraqueza muscular assimétrica. A apresentação assimétrica da fraqueza muscular foi frequente, podendo afetar a postura e a funcionalidade. O desempenho funcional geralmente apresenta aumento no número de movimentos compensatórios. Não podemos sempre considerar o tempo como um bom marcador de funcionalidade para essa população, uma vez que não muda na mesma proporção que o número de compensações em todas essas pacientes. Conclusão: Fraqueza muscular assimétrica e movimentos compensatórios, ou ambos, podem ser encontrados em portadoras sintomáticas de DMD, o que pode afetar a postura e a funcionalidade dessas pacientes.
Subject(s)
Humans , Female , Child , Adolescent , Adult , Middle Aged , Muscular Dystrophy, Duchenne/diagnosis , Muscle Strength/physiology , Muscular Dystrophies/genetics , Cardiomyopathies/etiology , Polymerase Chain Reaction , Prevalence , Muscle Weakness/etiology , Muscle Weakness/epidemiology , Muscular Dystrophy, Duchenne/genetics , Muscular Dystrophy, Duchenne/epidemiology , Muscle Strength/genetics , Physical Functional Performance , Heterozygote , Muscular Dystrophies/physiopathology , Muscular Dystrophies/epidemiology , Mutation/genetics , Cardiomyopathies/epidemiologyABSTRACT
We investigated the effect of -174 G/C single-nucleotide polymorphism in the promoter region of the IL6 gene on plasma IL-6 levels and muscle strength, and the relationship between IL-6 levels and muscle strength in elderly women. The sample consisted of 199 elderly residents (73.0 ± 7.8 years old) from rest homes and the community in Belo Horizonte, MG, Brazil. -174 G/C polymorphism was determined by direct sequencing of the product by PCR, and plasma IL-6 concentrations were measured by ELISA. Muscle strength in the knee joint was evaluated using a Biodex System 3 Pro® isokinetic dynamometer. ANCOVA was used to determine the effect of polymorphism on IL-6 levels and muscle strength, and the Pearson correlation coefficient to assess the relationship between IL-6 levels and muscle strength. -174 G/C polymorphism was associated with the plasma IL-6 levels of elderly women (P < 0.01) since homozygotes for the G allele showed high IL-6 levels (GG 3.85 pg/mL, GC + CC 2.13 pg/mL). There was no association of polymorphism on muscle strength (P > 0.05). No association was found between IL-6 levels and knee extensor muscle (r = 0.087, P = 0.306) or flexor (r = -0.011, P = 0.894) strength. An interaction between -174 G/C polymorphism and housing conditions of the sample of elderly women was identified, with the effect of genotype on IL-6 levels being higher in the institutionalized elderly. These results support the evidence that -174 G/C polymorphism of the IL6 gene associates with individual variability of plasma IL-6 levels in elderly women.