A patient with myofibrillar myopathy caused by BAG3 gene mutation / 中华神经科杂志

Objective To study the clinical,pathological and genetic features of myofibrillar myopathy caused by BAG3 gene mutation.Methods The clinical features and pathological findings of a patient with myofibrillar myopathy were analyzed.Genomic DNA of the patient was extracted from peripheral blood and the next generation sequencing was performed to explore the mutation of genes about myopathies.Results The patient presented with nine-year-old onset myopathy characterized by progressive difficulty for squatting,rigid spine and muscle atrophy in the limbs symmetrically.Peripheral neurogenic damages were found on electromyography.On muscle biopsy,myogenic and neurogenic damages with rimmed vacuoles appeared,and the deposited materials were positive for sarcoglycan,dystrophin-R and dystrophin-C.There was a reported heterozygous mutation in the exons of the BAG3 gene (c.626C ＞ T).Conclusion There is no specificity of clinical manifestation in myofibrillar myopathy,and the diagnosis of this disease mainly depends on muscle biopsy and genetic screening.

Clinical and pathological features of 12 cases with nemaline myopathy / 中华神经科杂志

Objective To study the clinical and pathological features of nemaline myopathy(NM) in 12 cases.Methods Clinical manifestations and pathological features of muscle-biopsy specimens were summarized and analyzed retrospectively in 12 NM cases.Results In 12 cases,7 patients with typical congenital type exhibited lower or four limbs weakness as the first symptom and benign course.Three patients with childhood onset type exhibited lower limbs weakness and progressive course,and this type of patient might have muscle atrophy.Two patients with adult onset type exhibited four limbs and throat muscle weakness,rapidly progressive course and obvious muscle atrophy,and one patient had already shown acute respiratory failure.High arched feet and elongated face were observed.Creatin kinase value in all patients was normal or mildly elevated,and all electromyography showed myogenic changes.In light microscopy,the nemaline bodies were observed in more than half muscle fibers,especially in type 1 fibers.All patients showed type 1 predominance and atrophy.Modified Gomori trichrome stains showed characteristic purplecolored rods.Muscle electron microscopy showed high electron dense nemaline bodies around nucleus and disorganized myofibrillar apparatus such as broken myofilaments,irregular myofibril and Z lines.Nemaline bodies under electron microscopy may be part of myofibril or high electron-dense bodies with no structure.Conclusions The 12 patients in this study with NM are divided into 3 types,of which adult onset type is the most severe one.The key diagnosis is based on the appearance of nemaline bodies in more than half of the muscle fibers and the muscle electron microscopy observation.

Histopathological Study of Extraocular Musele followinr Posterior Fixation Suture in Rabbits: Pathogenesis of Musele Fibrosis

The authors observed the histological and ultrastructural findings in a study of the fibrosis of the extraocular muscles following a posterior fixation suture in rabbits. the early findings demonstrated hyalinosis, clumping of the nuclei of muscle cells and collagenization of the muscle tissue. However, there was no evidence of collagen tissue in the degenerated muscle fiber, reserving cell membrane and basement membrane ultrastructurally. The late findings showed splitting and irregular stain of the muscle fibers, many nuclei of presumed muscle cell and filamentous structure at the collagen tissue in the extracellular space. Electron microscopic study showed atrophy and angulation with distortion of the myofibrillar matrix, along with other cytoplasmic degenerative phe nomena in the muscle fibers. Clumps of the well-arranged microfibrils(Mf) and irregularly arranged Mf with fine granular materials(FGM) were adjacent to the immature collagen fibrils. Many of the Mf and FGM were closely associated, and the number of the Mf and FGM decreased with the degree of maturity of the collagen fibrils. The anatomical structure of the myofibrill was identified as that of the Mf. From these findings, it would appear that formation of collagen fiber occurs in the extracellular space and that Mf and FGM are primarily responsible for the formation of the collagen fibils.