BAG3基因突变所致肌原纤维肌病一例

A patient with myofibrillar myopathy caused by BAG3 gene mutation

目的 通过对1例BAG3基因突变所致肌原纤维肌病的病例报道,分析该病的临床表现、病理特点以及基因突变情况.方法 收集1例肌原纤维肌病可能患者的临床资料,对其肌肉活体组织检查（活检）标本行酶组织化学以及免疫组织化学染色,并取其外周血进行DNA高通量测序.结果 本例患者9岁起病,病程5年余,表现为进行性下蹲困难伴脊柱强直,四肢对称性肌萎缩.肌电图示周围神经受损.肌肉病理示肌源性损害及神经源性损害伴有异常镶边空泡,B-肌聚糖蛋白膜蛋白缺陷,抗肌萎缩蛋白-R端缺陷,抗肌萎缩蛋白一C端缺陷.基因筛查在BAG3基因外显子区域发现1处杂合突变（c.626C＞ T）.结论 BAG3基因突变所致肌原纤维肌病的临床表现缺乏特异性,确诊主要依赖肌肉活检及基因筛查.

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.