Analysis of pathogenic mosaic mutations in human Amyotrophic Lateral Sclerosis nervous system

摘要 肌萎缩侧索硬化症(ALS)是一种进行性神经退行性疾病，其特征是 脊髓和大脑中的运动神经元。虽然几个已知基因的常染色体显性突变可以 引起家族性肌萎缩侧索硬化症，大多数肌萎缩侧索硬化症病例(90-95%)没有家族史，因此被归类为散发性。 导致散发性肌萎缩侧索硬化症的机制知之甚少，阻碍了治疗和治愈方法的寻找。 体细胞突变是在受精后产生的DNA变体，因此在体内是镶嵌的，体细胞突变 突变已被证明是几种非遗传性神经疾病的原因。我们的建议旨在 测试脊髓或大脑中ALS风险基因或其他基因的体细胞突变是否会导致零星的 肌萎缩侧索硬化。为了验证这一假设，我们将使用跨学科的方法，结合临床上的专业知识 肌萎缩侧索硬化症的特征和遗传学来自罗伯特·布朗·迪菲尔的实验室，医学博士，具有体液学专业知识 迈克尔·洛达托博士实验室的突变和单细胞分析。我们将分析一个 联盟生成的全基因组测序(WGS)数据集，并分析超深层的体细胞突变 (500X)本提案中产生的完整外显子组测序(WES)数据。这些实验将使我们能够 研究影响所有胚胎阶段散发性肌萎缩侧索硬化症的体细胞突变，包括早期体细胞突变 分布在全身，以及可能发生在承诺的中心的胚胎晚期体细胞突变 神经系统的祖细胞，仅限于大脑和脊髓。我们的初步数据显示， 捐献者的特点是体细胞突变，其中一些会产生预测的有害变化。如果成功， 我们将在ALS遗传学上开辟一个新的前沿，并定义最近候选的新患者队列 开发出针对突变的个性化治疗方法。

Summary Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by the loss of motor neurons in the spinal cord and brain. While autosomal dominant mutations in several known genes can cause familial ALS, most ALS cases (90-95%) display no family history so are classified as sporadic. Mechanisms driving sporadic ALS are poorly understood, hindering the search for treatments and a cure. Somatic mutations are DNA variants that arise after fertilization and are thus mosaic in the body, and somatic mutations have been shown to be causal in several non-inherited neurological disorders. Our proposal aims to test whether somatic mutations, in ALS risk genes or other genes, in the spinal cord or brain can cause sporadic ALS. To test this hypothesis, we will use an interdisciplinary approach, combining the expertise in the clinical features and genetics of ALS from the laboratory of Robert Brown DPhil., M.D. with expertise in somatic mutations and single-cell analysis in the lab of Michael Lodato, Ph.D. We will analyze somatic mutations in a consortium-generated whole-genome sequencing (WGS) dataset, and analyze somatic mutations in ultra-deep (500x) whole-exome sequencing (WES) data generated in this proposal. These experiments will allow us to study somatic mutations impacting sporadic ALS at all embryonic stages, including early somatic mutations distributed across the body, and late embryonic somatic mutations that might occur in a committed central nervous system progenitor and be restricted to the brain and spinal cord. Our preliminary data suggest that all donors are marked by somatic mutations, some of which generate predicted deleterious changes. If successful, we will open a new frontier in ALS genetics, and define new patient cohorts who are candidates for recently developed, mutation-specific personalized therapeutics.