Selcen Duygu, Engel Andrew G
Department of Neurology and Neuromuscular Disease Research Laboratory, Mayo Clinic, Rochester, MN 55905, USA.
Handb Clin Neurol. 2011;101:143-54. doi: 10.1016/B978-0-08-045031-5.00011-6.
Myofibrillar myopathies (MFMs) represent a group of muscular dystrophies with a similar morphological phenotype. The diagnosis is established by muscle biopsy. The MFMs are characterized by a distinct pathological pattern of myofibrillar dissolution associated with disintegration of the Z-disk, accumulation of myofibrillar degradation products, and ectopic expression of multiple proteins that include desmin, αB-crystallin, dystrophin, and sometimes congophilic material. The clinical features of MFMs are more variable. These include progressive muscle weakness that often involves or begins in distal muscles, but limb-girdle or scapuloperoneal distributions can also occur. Cardiomyopathy and peripheral neuropathy are frequent associated features. Electromyography of the affected muscles reveals myopathic motor unit potentials and abnormal irritability, often with myotonic discharges. Rarely, neurogenic motor unit potentials or slowing of nerve conduction velocities are present. To date, all MFM mutations have appeared in Z-disk-associated proteins: namely, desmin, αB-crystallin, myotilin, ZASP, filamin C, and Bag3. However, in the majority of patients with MFM, the disease gene awaits discovery.
肌原纤维肌病（MFMs）是一组具有相似形态学表型的肌肉萎缩症。诊断通过肌肉活检确定。MFMs的特征是肌原纤维溶解的独特病理模式，伴有Z盘解体、肌原纤维降解产物积累以及多种蛋白质的异位表达，这些蛋白质包括结蛋白、αB晶状体蛋白、肌营养不良蛋白，有时还有嗜刚果红物质。MFMs的临床特征变化更大。这些包括进行性肌肉无力，通常累及或始于远端肌肉，但也可能出现肢带型或肩胛腓骨型分布。心肌病和周围神经病变是常见的伴随特征。对受影响肌肉进行肌电图检查可发现肌病性运动单位电位和异常兴奋性，常伴有肌强直放电。很少出现神经源性运动单位电位或神经传导速度减慢。迄今为止，所有MFM突变都出现在与Z盘相关的蛋白质中，即结蛋白、αB晶状体蛋白、肌联蛋白、ZASP、细丝蛋白C和Bag3。然而，在大多数MFM患者中，致病基因仍有待发现。
