Investigating Divergent Disease Severity in Human Neuronal Models of KCNQ2-Related Developmental and Epilepsy Disorders

编码电压门控性K+（KV7.2）通道的KCNQ2突变与单基因早发性 特征重叠但临床严重程度不同的儿童癫痫。的临床谱 KCNQ2相关癫痫疾病包括常染色体显性遗传的良性家族性新生儿癫痫发作（BFNS） 严重发育性和癫痫性脑病（DEE）的散发病例。KCNQ2帐户中的突变 在遗传性癫痫中发现的所有突变中约有5%，在早发性癫痫相关突变中约有10%， 癫痫导致BFNS和DEE病例之间严重程度差异的机制很差， 明白目前，30%的癫痫患者对任何现有的抗癫痫药物都是完全难治的 治疗和没有治疗终身发展和身体残疾相关的 迪伊因此，解决这一首要问题可以促进新的靶向治疗药物的开发。 战略布局使用异源表达系统和小鼠模型的研究已经提供了许多进展 我们对KCNQ2相关癫痫的理解，但未能解释一些表型癫痫的来源， 与人类大脑的细胞和网络水平发育相关的变异。由于这些 局限性存在开发用于癫痫的更多人类相关模型系统的根本需要。最近 在产生人类患者特异性诱导多能干细胞（hiPSC）方面的进展使得 将患者体细胞重编程为多能性并分化为神经元。因此本 一项提案试图利用这些技术来解决KCNQ2中的稳定突变如何影响：1） 特定人类神经元亚型内在和网络兴奋性和2）电生理学成熟， 复杂神经元网络的可塑性，以确定这些特性是否在疾病严重程度中改变 具体方式。在这里，我们将使用已建立的基于患者特异性iPSC的平台来确定BFNS如何 使用膜片钳电生理学和多电极技术， 阵列（MEA）技术。

Mutations in KCNQ2 encoding voltage-gated K+ (KV7.2) channel are associated with monogenic early-onset childhood epilepsies with overlapping characteristics but divergent clinical severity. The clinical spectrum of KCNQ2-related epilepsy disorders ranges from autosomal-dominant Benign Familial Neonatal Seizures (BFNS) to sporadic cases of severe Developmental and Epileptic Encephalopathy (DEE). Mutations in KCNQ2 account for approximately 5% of all mutations identified in genetic epilepsy and 10% of those associated with early-onset epilepsy. The mechanisms that drive the differential severity between BFNS and DEE cases are poorly understood. Currently 30% of all epilepsy patients are completely refractory to any existing anti-epileptic treatments and there are no treatments for the lifelong developmental and physical disabilities associated with DEE. Thus, addressing this overarching question can facilitate development of novel and targeted therapeutic strategies. Studies using heterologous expression systems and mouse models have provided many advances in our understanding of KCNQ2-related epilepsies, but fail to account for some of the sources of phenotypic variation associated with cellular and network-level development of the human brain. As a result of these limitations there is a fundamental need to develop more human-relevant model systems for epilepsy. Recent advances in the generation of human patient-specific induced pluripotent stem cells (hiPSCs) have allowed patient somatic cells to be reprogrammed to pluripotency and differentiated into neurons. Thus, the present proposal seeks to take advantage of these technologies to address how stable mutations in KCNQ2 affect: 1) intrinsic and network excitability in specific human neuronal subtypes and 2) electrophysiological maturation and plasticity of complex neuronal networks to determine whether these properties are altered in a disease-severity specific manner. Here, we will use an established patient-specific iPSC-based platform to determine how BFNS and DEE variants differentially impact human neurons using patch-clamp electrophysiology and multi-electrode array (MEA) techniques.