运动诱发性运动障碍患者PRRT2基因检测及静息态功能磁共振研究

发布时间：2018-04-29 16:08

  本文选题：发作性运动诱发性运动障碍 + 临床特征　； 参考：《浙江大学》2014年博士论文

【摘要】：发作性运动障碍(Paroxysmal dyskinesia PxD)是一组具有高度临床异质性的运动障碍性疾病,依据发作前先兆、发作期表现、持续时间、病程长短及病因等进行分类。其中发作性运动诱发性运动障碍(Paroxysmal Kinesigenic dyskinesiasPKD)是最常见的类型,临床表现独特主要为突然运动或改变运动方式后出现的不自主运动,包括肌张力障碍的姿势、舞蹈样动作、手足徐动症、偏身投掷及各种不自主运动的组合,饮用咖啡、机体疲劳、寒冷时可能降低发作的阈值。发作可以是单侧或双侧或左右交替发生,有时累及面部和口咽肌肉时可出现发音困难。根据病因的不同可以分为原发性和继发性发作性运动障碍。PKD具有家族史的患者约占到40-70%,符合常染色体显性遗传规律。由于PKD临床表现具有发作性、短暂性和刻板性特征,因而常被误诊为癫痫。目前认为PKD的致病基因是位于16号染色体上的PRRT2(Proline-RichTransmembrane Protein2)基因,该基因是富含脯氨酸的跨膜蛋白,且是一种突触前膜蛋白,在细胞胞吐作用和神经递质的释放过程中发挥重要的作用,但基因突变致病的具体机制仍不清楚,临床表型与基因型的关系也不明确。迄今为止已报道大约超过300个PKD家系及散发患者含有PRRT2基因突变。超过80%的家系报道突变类型为c.649-650insC; p.Arg217Profs*8,其他突变类型还包括错义突变、无义突变及剪切位点的突变,这些突变常导致截短蛋白的形成,从而使得蛋白的细胞内定位及表达量发生明显的变化。目前为止大概有15个不同的错义突变报道,而这些错义突变的位点多集中在以往认为是跨膜转运结构域的C末端。同时功能研究发现PRRT2基因在锥体外系、皮层等高表达,且随年龄增长表达量下降。 而功能磁共振成像(functional magnetic resonance imaging,fMRI)是一种在活体人脑中定位各功能区的有效方法,其中静息态功能磁共振研究具有较高的空间分辨率,且无需任务设计的复杂,有助于在活体条件下研究PKD患者静息状态时脑功能活动的异常。既往也有研究对PKD患者应用静息态功能磁共振研究发现存在基底节区的信号异常,提示与PRRT2的基因表达存在一定的关联性。 因而为进一步明确PKD患者的临床特点、PRRT2基因的突变情况及在静息态磁共振是否存在一致的功能改变,本课题分两部分：第一部分回顾分析了72例PKD患者的临床特点并对其中27例患者进行PRRT2基因突变检测,旨在综合分析疾病的临床特点,提高对PKD的诊疗水平；并了解PRRT2基因突变情况,为进一步研究疾病基因突变型与临床表型关系及具体的致病机理奠定基础。第二部分选择29例PKD患者利用静息态功能磁共振技术,采用ALFF方法计算PKD患者和正常对照的静息态全脑自发脑活动模式；并计算PKD患者与正常对照的ReHo图,对比分析PKD患者的局部脑区之间活动的一致性特征,为进一步在体研究PKD的发病机理提供依据。 第一部分运动诱发性运动障碍患者的临床特征分析及PRRT2基因突变检测目的： 回顾分析PKD家系和散发患者的临床资料,综合分析疾病的临床特点,加深临床对疾病的认识,以进一步提高对PKD的诊疗水平；同时对其中27例患者进行PRRT2基因突变检测,旨在了解PRRT2基因突变情况,为进一步研究疾病基因突变型与表型关系及具体的致病机理奠定基础。 方法： 对64例散发性PKD患者和8例遗传性PKD先证者的临床资料、神经系统体格检查、电生理及影像资料等结果进行系统回顾性分析。同时对4例具有家族史的患者及23例散发患者抽提外周血DNA进行PRRT2基因全部外显子及剪切相关内含子区域突变检测分析。 结果： PKD患者男女比例约3.5：1,平均发病年龄12.93±3.96岁,临床发作常在突然运动、改变运动形式及紧张时出现,发作表现为单侧或双侧肢体异常运动,肢体、躯干或面部均可受累。每次发作持续数秒至数十秒,最长不超过1.5分钟,多伴有先兆,应用抗癫痫药物效果良好。PRRT2基因外显子的基因突变检测分析共发现4例突变c.981ATCATG p.327IleMet; c.649-650insC p.Arg217Profs*8; c.649CGATGA p.217ArgTer(end); c.5GCAGTA p.2AlaVal。其中c.5GCAGTA p.2AlaVal为新发突变,且突变型与临床表型无直接相关性。 结论： 1.发作性运动诱发性运动障碍(PKD)是发作性肌张力障碍中最常见的一种类型,临床表现具有异质性。主要为突然运动、改变运动方式、紧张及寒冷后出现的肢体、躯干或面部的不自主运动；2.PRRT2基因突变研究发现其中位于非编码区的c5GCAGTA p.2AlaVal为国内外首次报道；PRRT2在散发患者中突变频率约30%,可能存在除PRRT2基因之外的致病因素；基因突变型与临床表型无明显相关性。 第二部分运动诱发性运动障碍患者静息态功能磁共振研究 目的： 利用静息态功能磁共振技术,采用ALFF方法对比分析PKD患者和正常对照的静息态全脑自发脑活动模式；并计算PKD患者与正常对照的ReHo图,对比分析PKD患者的局部脑区之间活动的一致性特征,为进一步在体研究PKD的发病机理提供依据。 方法： 对29例PKD患者和14例正常对照进行静息态磁共振扫描,利用REST、DPARSF和SPM8软件完成功能像的预处理,分别进行ALFF分析及ReHo值的计算,采用单样本t检验,得到两组被试组内的全脑低频振幅模式及ReHo统计图；采用双样本t检验,对PKD组与正常对照组ALFF图和ReHo图进行组间比较分析。 结果： PKD和对照组的单样本结果模式基本一致,ALFF值组间比较发现,PKD患者的后扣带皮层和运动前皮质ALFF值显著高于正常对照；而额下回、视觉皮层、海马、颞极以及舌回的ALFF值显著低于正常对照；ReHo值组间比较发现,PKD患者的默认网络相关脑区局部一致性增强,如楔前叶/后扣带皮层、顶下小叶和额上回,运动前皮质的局部一致性也显著高于正常对照；而左侧颞上回的局部一致性显著低于正常对照。 结论： 本研究采用静息态fMRI为研究范式,从局部独立活动和局部连接特征两个方面刻画了PKD患者的脑功能特征。研究结果表明,无论是用ALFF和ReHo都发现患者运动前皮层的活动特征存在异常：独立活动增强、局部连接增强。提示运动前皮层是理解PKD病理生理机制的重要节点。为后续的研究提供了感兴趣区。发作间期所观察到的这种高兴奋性或许能为评估患者病情提供客观的影像学标。
[Abstract]:Paroxysmal dyskinesia (Paroxysmal dyskinesia PxD) is a group of highly clinically heterogeneous dyskinesia. It is classified according to preparoxysmal precursory, episodic performance, duration, duration of disease and etiology, and the most common type of Paroxysmal Kinesigenic dyskinesiasPKD is paroxysmal motor induced dyskinesia (Kinesigenic dyskinesiasPKD) Involuntary movement, especially after sudden movement or change of movement, including dystonia posture, dystonia, huttocystoesoootism, body throwing and various combinations of involuntary movements. Drinking coffee, body fatigue, and cold may reduce the threshold of seizures. Seizures can be unilateral or bilateral or left. It occurs alternately on the right, sometimes involving the facial and oropharyngeal muscles, which can be dysphagiated. According to the difference of the cause, the patients with primary and secondary paroxysmal dyskinesia account for about 40-70%, which conforms to the autosomal dominant inheritance law. The clinical manifestations of PKD are characterized by episodes, transient and stereotyped characteristics, because of PKD clinical manifestations. It is often misdiagnosed as epilepsy. It is believed that the PKD gene is the PRRT2 (Proline-RichTransmembrane Protein2) gene located on chromosome 16. The gene is a proline rich transmembrane protein and a presynaptic membrane protein that plays an important role in the process of cell emetic and neurotransmitter release, but gene mutation The specific mechanism of the disease is still unclear, and the relationship between the clinical phenotype and genotype is not clear. Up to 300 PKD families and sporadic patients have been reported to have PRRT2 mutations. More than 80% of the families reported mutations in c.649-650insC; p.Arg217Profs*8, and other types of mutation, nonsense mutation and shear. Mutations in the loci, which often lead to the formation of truncated proteins, make a significant change in the intracellular localization and expression of the protein. So far, there are about 15 different missense mutations reported, and these missense mutations are mostly concentrated in the C terminal, which was previously thought to be transmembrane transshipment domains. And functional research found that PRR T2 gene was highly expressed in extrapyramidal and cortical regions, and decreased with age.
Functional magnetic resonance imaging (fMRI) is an effective method to locate various functional areas in the living human brain. The resting state functional magnetic resonance (fMRI) study has high spatial resolution and does not need the complexity of task design. It is helpful for the study of the brain function activity in the resting state of PKD patients under the living condition. Previous studies have also studied the application of resting state functional magnetic resonance (fMRI) to PKD patients to find that there is a signal anomaly in the basal ganglia, suggesting a certain correlation with the gene expression of PRRT2.
Therefore, in order to further clarify the clinical characteristics of PKD patients, the mutation of PRRT2 gene and whether there is a consistent functional change in resting state magnetic resonance, this topic is divided into two parts: the first part reviewed and analyzed the clinical characteristics of 72 cases of PKD patients and 27 patients with PRRT2 mutation detection, aiming at the comprehensive analysis of the clinical symptoms of the disease. Characteristics, improve the diagnosis and treatment of PKD, and understand the mutation of PRRT2 gene, in order to further study the relationship between the mutation of the disease gene and the clinical phenotype and the specific pathogenesis. The second part selected 29 cases of PKD patients to use the resting state function magnetic resonance technique and the ALFF square method to calculate the rest state of the patients with PKD and the normal control. The spontaneous brain activity pattern of the brain and the ReHo map of the PKD patients and the normal control were calculated, and the conformance characteristics of the activities between the local brain regions of the PKD patients were compared and analyzed to provide the basis for further study of the pathogenesis of PKD in vivo.
Part one: analysis of clinical characteristics and PRRT2 gene mutation in patients with exercise-induced dyskinesia.
The clinical data of PKD family and sporadic patients were reviewed, the clinical features of the disease were analyzed, and the clinical knowledge of the disease was deepened to further improve the level of diagnosis and treatment of PKD. At the same time, the mutation detection of PRRT2 gene was carried out in 27 of the patients to understand the mutation of the PRRT2 gene and to further study the mutant and phenotype of the disease gene. It lays the foundation for the relationship and the specific pathogenicity mechanism.
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