两例继发性dystrophin蛋白缺失现象病例的研究及文献复习

发布时间：2018-04-01 13:39

本文选题：DMD/BMD　切入点：dystrophin蛋白　出处：《山东大学》2014年硕士论文

【摘要】：背景和目的 Dystrophin蛋白广泛存在于所有肌肉细胞、部分神经细胞的胞膜上,作为细胞骨架的一部分,该蛋白与dystroglycan、sarcoglycan等一系列蛋白共同构成dystrophin相关蛋白复合体(dystrophin associated protein complex, D APC),在肌肉收缩过程中维持细胞稳定性及力的传导发挥重要作用。Dystrophin蛋白的编码基因定位于Xp21,是迄今发现的人类最大的基因。当dystrophin基因发生突变,dystrophin蛋白合成障碍,在临床上表现为Duchenne或Becker肌营养不良(DMD/BMD),此为dystrophin蛋白的原发性缺失。本文报道两例继发性dystrophin蛋白缺失现象病例,并对常见的dystrophin蛋白缺失现象进行总结及鉴别。材料方法两例患者均来自山东大学齐鲁医院神经内科门诊,因肢体抖动、癫痫及不同程度的肌无力而行肌肉活检术。除此二例患者外,另选取山东大学齐鲁医院神经肌肉病研究室2例DMD患者肌肉标本,1例BMD患者肌肉标本及1例常规染色正常的肌肉标本作为对照,对上述病例肌肉标本进行常规病理染色、免疫组织化学染色、dystrophin蛋白免疫荧光染色,提取肌肉组织总蛋白进行dystrophin蛋白印迹分析,并对两例患者行dystrophin基因检测。结果病例1常规病理染色提示轻度神经源性损害,免疫组织化学染色及免疫荧光不dystrophin rod染色肌纤维膜普遍减弱。Dystrophin蛋白免疫印迹提示dystrophin rod表达量降低。Dystrophin基因MLPA检测提示79个外显子的结果均为正常,未检测到任何缺失突变或重复,NGS测序提示检测到多个多态性位点：rs1484852, rs1800280, rs1379871, rs187617705, rs228406。病例2常规病理染色示大致正常肌组织,免疫组织化学染色及免疫荧光示dystrophin rod染色肌纤维膜普遍不着色。Dystrophin蛋白免疫印迹提示蛋白表达量降低。Dystrophin基因MLPA检测提示79个外显子的结果均为正常,未检测到任何缺失突变或重复,NGS测序提示检测到一个半合子突变：c.4048CT, p.(Arg1350Cys). 结论两例患者dystrophin基因未发生致病突变,其肌肉组织为继发性dystroph in蛋白缺失。两例患者均有肌肉异常收缩病史,异常的肌肉收缩导致dystroph in蛋白的继发缺失。在神经肌肉病的诊断中,应在常规病理、IHC的基础上,结合临床表现,必要时借助免疫荧光、WB、基因检测等手段做出诊断。
[Abstract]:Background and purpose. Dystrophin protein is widely found in all muscle cells, part of the cell membrane, as part of the cytoskeleton. This protein, together with a series of proteins, such as dystroglycan sarcoglycan, constitutes the dystrophin associated protein complex dystrophin associated protein complex. It plays an important role in maintaining cell stability and force conduction during muscle contraction. The gene encoding Dystrophin protein is located in Xp21. When the dystrophin gene mutated dystrophin protein synthesis, The clinical manifestations are Duchenne or Becker dystrophy, which is the primary deletion of dystrophin protein. This paper reports two cases of secondary dystrophin protein deletion, and summarizes and distinguishes the common dystrophin protein deletion phenomenon. Material method. The two patients, all from the Department of Neurology, Qilu Hospital, Shandong University, underwent muscle biopsy because of limb jitter, epilepsy and different degrees of myasthenia. The muscle specimens of 2 cases of DMD patients and 1 case of BMD patients and 1 case of normal muscle specimens with normal staining were selected as control group. The muscle specimens of these cases were stained by routine pathological staining. Immunohistochemical staining of dystrophin protein was performed by immunofluorescence staining. Total protein of muscle tissue was extracted for dystrophin blot analysis and dystrophin gene was detected in two patients. Results. Case 1 showed mild neurogenic damage by routine pathological staining. Immunohistochemical staining and immunofluorescence non dystrophin rod staining showed that the myofibril membrane was generally weakened. Dystrophin immunoblotting indicated that the expression of dystrophin rod decreased. MLPA detection of Dystrophin gene indicated that the results of 79 exons were normal. No deletion mutation or repeated NGS sequencing indicated that multiple polymorphic loci: rs1484852, rs1800280, rs1379871, rs187617705, rs228406 were detected. In case 2, routine pathological staining showed that the muscle tissue was approximately normal. Immunohistochemical staining and immunofluorescence staining showed that the expression of Dystrophin protein was decreased by dystrophin rod staining. Dystrophin gene MLPA showed that the results of 79 exons were normal. No deletion mutation was detected or repeated NGS sequencing indicated that a half zygote mutation was detected: 1 / c. 4048 CTA, p. Arg1350 Cyschus. Conclusion. The dystrophin gene was not mutated in two patients, and its muscle tissue was secondary dystroph in deletion. Both patients had a history of abnormal muscle contraction, and abnormal muscle contraction resulted in the secondary deletion of dystroph in the diagnosis of neuromuscular diseases. The diagnosis should be based on the routine pathology of IHC, combined with clinical manifestations, and the diagnosis should be made by means of immunofluorescence, gene detection and so on.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R746

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