Congenital Myasthenic Syndromes

项目摘要 要求支持先天性肌无力综合征（CMS）的多方面调查。的CMS 是异质性和致残性疾病，其中神经肌肉传递的安全范围是 受到一个或多个特定机制的损害。我们将使用候选基因方法结合 全外显子组测序，以找到不同CMS的原因，确定突变的机制， 基因导致CMS，然后使用这些信息来产生结构-功能相关性，并设计 治疗策略。 候选基因的方法依赖于确定（1）临床表型，（2）形态表型 根据终板（EP）的细胞化学和超微结构特征，（3）乙酰胆碱（ACh）的数量 受体（AChRs），（4）神经肌肉参数反映的电生理表型 体外传播通过工程方法研究了该突变基因引起CMS的机理 将突变体和相应的野生型基因导入合适的表达系统，然后通过 适当的电生理和生化测试。结构-功能相关性依赖于 诱变研究和突变的结构变化的机制分析， 蛋白质改变了该蛋白质的功能，以及这种改变如何影响神经肌肉的安全范围。 传输治疗策略是基于确定突变引起的分子缺陷 以及所鉴定的缺陷是否增加或减少对ACh的突触反应。

PROJECT SUMMARY Support is requested for a multifaceted investigation of congenital myasthenic syndromes (CMS). The CMS are heterogeneous and disabling diseases in which the safety margin of neuromuscular transmission is compromised by one or more specific mechanism(s). We will use the candidate gene approach combined with whole exome sequencing to find the cause of different CMS, determine the mechanism by which the mutant gene causes the CMS, and then use this information to generate structure-function correlations and devise strategies for therapy. The candidate gene approach rests on determining (1) the clinical phenotype, (2) the morphologic phenotype based on cytochemical and ultrastructural features of the endplate (EP), (3) the number of acetylcholine (ACh) receptors (AChRs) per EP, (4) the electrophysiologic phenotype reflected by parameters of neuromuscular transmission in vitro. The mechanism by which the mutant gene causes a CMS is investigated by engineering the mutant and corresponding wild-type gene into a suitable expression system which is then interrogated by appropriate electrophysiologic and biochemical tests. Structure–function correlations rest on further mutagenesis studies and on analysis of the mechanism by which a change in the structure of the mutated protein alters the function of that protein, and how this alteration affects the safety margin of neuromuscular transmission. Strategies for therapy are based on determining the molecular defect caused by the mutation and whether the identified defect increases or decreases the synaptic response to ACh.