Models to study heritable and de novo DAND mutations

项目摘要 DEAF 1相关神经发育障碍（DAND）是一种表型谱特征，包括 智力残疾和自闭症谱系障碍（ASD）。DAND患者的临床表型 与其他神经发育障碍重叠，包括Angelman和Rett综合征。DAND由以下原因引起： DEAF 1基因中的单等位基因从头突变和双等位基因可遗传突变。我们的功能研究表明， 鉴定的从头突变破坏了DEAF 1的转录活性，并表明突变是显性的， 阴性遗传变异对DEAF 1功能的影响尚不清楚。该提案重点关注两个 鉴定了DEAF 1变体，p.Q264P（从头）和p.R226W（遗传）。由此产生的频谱紊乱 具有遗传性和新发DEAF 1突变的个体非常相似。我们假设 一组常见的改变的DEAF 1靶基因，由可遗传的和新生的DEAF 1突变引起， DAND的发病机制。该提案的创新之处在于开发了新的模型系统， 密切关注DAND。目前评估DEAF 1活性降低对 认知功能是一种条件性敲除模型。尽管淘汰赛模型证明了 DEAF 1在学习和记忆中的表达，它并不反映DAND的等位基因特征，更重要的是， 占显性负或可能的功能获得行动的突变体DEAF 1蛋白。我们将使用 CRISPR/Cas9介导的基因组工程以开发p.R227W和p.Q265P（类似于p.R226W和p.Q265P） p.Q264P）点突变敲入DAND小鼠模型。神经行为测试将评估 DEAF 1突变蛋白对学习和记忆的影响我们还将确定转录组的变化， 出生后发育和成年海马。一组共同的差异表达基因，可能是导致 认知缺陷将通过比较这两个模型来确定。这些模型将提供重要的 深入了解DAND，以及其他具有重叠临床表型的发育障碍。

Project Summary DEAF1-associated neurodevelopmental disorder (DAND) is a phenotypic spectrum of features that include intellectual disability and autism spectrum disorder (ASD). Individuals with DAND have clinical phenotypes that overlap with other neurodevelopmental disorders including Angelman and Rett syndromes. DAND is caused by single allelic de novo and bi-allelic heritable mutations in the DEAF1 gene. Our functional studies indicate that identified de novo mutations disrupt DEAF1 transcriptional activity and suggest that the mutations are dominant negative. The effects of heritable variants on DEAF1 function remain unclear. This proposal focuses on two identified DEAF1 variants, p.Q264P (de novo) and p.R226W (heritable). The resultant spectrum disorders of individuals with heritable and de novo DEAF1 mutations is remarkably quite similar. We hypothesize there is a common set of altered DEAF1 target genes, caused by the heritable and de novo DEAF1 mutations, that underlie the pathogenesis of DAND. The innovation of this proposal is the development of new model systems that more closely represent DAND. The current best model for assessing the effects of decreased DEAF1 activity on cognitive function is a conditional knockout model. Although the knockout model demonstrates the importance of DEAF1 expression in learning and memory, it does not mirror the allelic profile of DAND or, more importantly, account for dominant negative or possible gain-of-function actions of the mutant DEAF1 proteins. We will use CRISPR/Cas9-mediated genomic engineering to develop p.R227W and p.Q265P (analogous to p.R226W and p.Q264P in humans) point mutation knock-in mouse models of DAND. Neurobehavioral testing will assess the effects of mutant DEAF1 proteins on learning and memory. We will also identify transcriptomic changes in postnatal developing and adult hippocampus. A common set of differentially expressed genes, likely causal to the cognitive deficits, will be determined by comparing these two models. These models will provide important insights into DAND, as well as other developmental disorders with overlapping clinical phenotypes.