CLINICAL, GENETIC, AND CELLULAR CONSEQUENCES OF MUTATIONS IN NA,K-ATPASE ATP1A3

摘要：Na/K泵神经元α3亚单位基因的神经学重要性， ATP1A3，强调了其错义突变产生的症状的严重性和范围：运动， 认知的和心理的。该项目采用了跨学科的综合方法。它包括 对输入新表型和机制因素的患者进行表型分析。因为新的表型 正在逐步被发现，这是一种基因优先搜索数据库中的变异、表型和风险因素 与临床数据相联系应该会加速这一进程。变种需要验证，因此将有实验室测试 致病性和机制，以及FDA批准的药物将进行救援测试。其目的是生成 未来临床试验和临床前所需的症状和进展的全面自然病史 潜在治疗的数据。ATP1A3有一系列非同寻常的症状，包括严重的 婴儿的表现，但这里的重点是在青年和成年人表现的综合征：仍然有一个 沉重的负担，但也可能是对改善生活质量的治疗的更直接的希望。 我们发现ATP1A3活性受损的症状包括心脏 节律的发生，在大脑中，我们发现了局灶性萎缩和其他仅减少的患者 通过核磁共振进行代谢，在那里有恢复功能的希望。此外，ATP1A3疾病与许多 神经综合征，包括但不限于自闭症、肌张力障碍、帕金森症、精神疾病和 癫痫。我们预计，拟议工作的结果也将指出Na，K-ATPase功能障碍 导致了这些更常见的疾病。 我们现在的目标是通过完善我们对ATP1A3突变表型的理解来进行治疗 多样性和机制。目标1)扩大ATP1A3的广度和覆盖范围 表型，使用诊断工具检测ATP1A3相关疾病并测量随时间的变化， 这是设计治疗试验所必需的。目的2)评估ATP1A3突变既是致病因素又是危险因素 通过使用基因优先的方法来搜索现有的大量人口和疾病来使疾病失效- ATP1A3变异体的特定序列数据库，并将这些数据库与Linked的表型数据关联 电子健康记录(EHR)或疾病特定表型数据。因为ATP1A3突变几乎是 完全错误和杂合，受损的蛋白质必须存在，从而导致目标3)： 研究患者在严格可比的同源细胞中蛋白质错误折叠的多个突变 台词。这将检验这样一种假设，即不同的症状群在细胞对 错误折叠：适应还是细胞凋亡。对于发生错误折叠的突变，测试FDA批准的和新的错误折叠 矫正药物的疗效。从长远来看，无论是纵向表型还是对突变蛋白的了解 功能对于选择药理学或基因治疗试验的患者亚组将是至关重要的。

Summary: The neurological importance of the gene for the neuronal alpha3 subunit of the Na/K pump, ATP1A3, is underscored by the severity and range of symptoms produced by its missense mutations: motor, cognitive, and psychological. This project uses an integrated interdisciplinary approach. It includes phenotyping on patients with input on new phenotypes and mechanistic factors. Because new phenotypes are being discovered incrementally, a gene-first search for variants, phenotypes and risk factors in databases linked to clinical data should accelerate that. Variants need to be validated, so there will be laboratory tests of pathogenicity and mechanism, and FDA-approved drugs will be tested for rescue. The purpose is to generate a comprehensive natural history of symptoms and progression needed for future clinical trials, and preclinical data for potential treatments. With ATP1A3 there is an extraordinary range of symptoms including severe infantile manifestations, but the focus here is on the syndromes that manifest in youth and adults: still with a heavy burden, but perhaps also with more immediate hope for treatments that improve the quality of life. We have found that the breadth of symptoms from impaired ATP1A3 activity includes cardiac rhythmogenesis, and in the brain, we have found patients with focal atrophy and others with only reduced metabolism by MRI, where there is hope of restoring function. Moreover, ATP1A3 disease overlaps with many neurologic syndromes, including but not limited to autism, dystonia, parkinsonism, psychiatric disease, and epilepsy. We anticipate that the results of the proposed work will also point to how Na,K-ATPase dysfunction contributes to these more common diseases. Our goal now is towards a treatment by refining our understanding of ATP1A3 mutation phenotype diversity and mechanisms. The aims are as follows: Aim 1) Expand the breadth and reach of ATP1A3 phenotyping, using diagnostic tools to detect ATP1A3-related disease and measure changes over time, necessary for designing treatment trials. Aim 2) Assess ATP1A3 mutations as both causative and risk factors for disabling diseases by using a genotype-first approach to search existing large population and disease- specific sequence databases for ATP1A3 variants and correlate these with phenotypic data from linked electronic health records (EHR) or disease specific phenotype data. Because ATP1A3 mutations are almost entirely missense and heterozygous, the damaged protein must have to be present, leading to Aim 3): Investigate multiple mutations from patients for protein misfolding in rigorously comparable isogenic cell lines. This will test the hypothesis that different symptom clusters have a basis in the cell’s responses to misfolding: adaptation or apoptosis. For mutations that do misfold, test FDA-approved and new misfolding corrector drugs for efficacy. In perspective, both longitudinal phenotyping and knowledge of mutant protein function will be essential for selecting the patient subgroups for either pharmacologic or gene therapy trials.