Discovery of Novel Molecular Abnormalities Underlying Non-Lesional Focal Epilepsy

描述（由申请人提供）：本提案的目标是探索分子异常的作用-体细胞突变，微生物核酸的存在，或两者-潜在的非病变局灶性癫痫（NLFE）。癫痫影响着世界上近1%的人口，1/3的患者对目前可用的抗惊厥药物没有反应。对于这些患者，癫痫控制的最大希望来自癫痫手术，切除癫痫病灶，当病灶可以识别时。在MRI上明确显示病因性病变的患者中，60-80%的患者术后无复发。在没有可识别的MRI病变的明确局灶性癫痫患者中，手术治愈率较低，范围为30- 50%。我们认为NLFE的问题是一个解决方案，即异常可能在MRI上不可见，但在分子水平上存在，以两种形式之一或两者：1）体细胞突变，局限于脑细胞和2）微生物，如病毒核酸的存在。 酸，这可能会导致分子异常和影响癫痫发作。有一些证据表明，体细胞突变在发育性结构病变如半侧巨脑畸形引起的癫痫中起作用，但体细胞突变尚未显示在非病变癫痫中发生。病毒感染在癫痫和皮质发育性分子病变中的作用已被提出，这是基于在患有内侧颞叶硬化的颞叶癫痫患者的脑组织中检测到HHV 6，以及最近在局灶性皮质发育不良（一种与癫痫密切相关的发育畸形）区域发现人乳头状瘤病毒。病毒在NLFE中更广泛的作用尚未得到证实，其他病原体的作用也未得到证实。我们将研究体细胞突变和微生物核酸是否存在于癫痫患者接受手术的癫痫灶中，使用下一代测序方法来确定切除脑组织中的这些分子异常。我们将使用系统生物学方法来实现这一点，整合最先进的皮质术中记录，以确定癫痫发作的重点，与临床，组织病理学和分子序列数据共同注册。因此，我们将创建一个具有详细表型数据的NLFE脑组织库，这将是同类中的第一个。证明癫痫发作可以由体细胞突变或感染引起，而不会改变大脑的宏观结构，这将改变理解癫痫发生的范式，并可能导致识别新的生物标志物和治疗方法。

DESCRIPTION (provided by applicant): The goal of this proposal is to explore the role of molecular abnormalities-somatic mutation, the presence of microbial nucleic acids, or both--underlying non-lesion focal epilepsy (NLFE). Epilepsy affects nearly 1% of the world's population and 1/3 of patients do not respond to currently available anticonvulsant medications. For these patients the best hope for seizure control comes from epilepsy surgery with resection of the seizure focus, when a focus can be identified. In patients for whom a causative lesion is clearly demonstrable on MRI, 60-80% of patients are seizure-free after surgery. In patients with clear focal epilepsy with no identifiable MRI lesion, surgical cure is less common, ranging from 30-50%. We propose that the problem of NLFE is one of resolution-that the abnormalities may not be visible on MRI but are present at the molecular level, in one or both of two forms: 1) somatic mutation, in cells restricted to brain and 2) the presence of microbial, e.g. viral nucleic acids, which may cause molecular abnormalities and influence epilepsy onset. There is some evidence to suggest that somatic mutation plays a role in epilepsies resulting from developmental structural lesions such as hemimegalencephaly, but somatic mutation has not yet been shown to occur in non-lesion epilepsies. The role of viral infection in epilepsy and developmental molecular lesions of the cortex has been suggested based on the detection of HHV6 in brain tissue from temporal lobe epilepsy patients with mesial temporal sclerosis and with the recent discovery of human papilloma virus in areas of focal cortical dysplasia, a developmental malformation strongly associated with epilepsy. The broader role of viruses in NLFE has not been demonstrated, nor the role of other pathogens. We will investigate whether somatic mutations and microbial nucleic acids are present in the seizure foci of individuals with epilepsy who undergo surgery, using next generation sequencing approaches to identify these molecular abnormalities in resected brain tissue. We will accomplish this using a systems biology approach, integrating state-of-the-art cortical intraoperative recordings to identify the seizure focus, co-registered with clinical, histopathology, and molecular sequence data. We will thereby create a repository of NLFE brain tissue with detailed phenotypic data which will be the first of its kind. Proving that seizures can arise from somatic mutations or infection without altering brain macrostructure would shift the paradigm for understanding epileptogenesis, and could lead to identification of novel biomarkers and treatments.