Models to study heritable and de novo DAND mutations

项目摘要 DEAF1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)。患有Dand的个体具有临床表型 与包括Angelman和Rett综合征在内的其他神经发育障碍重叠。Dand由以下原因引起 DEAF1基因的单等位基因新生和双等位基因可遗传突变。我们的功能研究表明 已发现的从头突变破坏了DEAF1的转录活性，并表明突变是显性的 不是。可遗传变异对DEAF1功能的影响尚不清楚。这项建议集中在两个方面 鉴定出DEAF1变异体，p.Q264P(从头)和p.R226W(可遗传)。由此产生的光谱紊乱 具有可遗传的和从头开始的DEAF1突变的个体非常相似。我们假设有一个 常见的一组改变的DEAF1靶基因，由可遗传的和从头开始的DEAF1突变引起 Dand的发病机制。这一建议的创新之处在于开发了更多的新模型系统 紧密代表Dand。目前评估DEAF1活性降低的影响的最佳模型 认知功能是一个条件性基因敲除模型。尽管淘汰赛模型证明了 在学习和记忆中DEAF1的表达，它并不反映Dand的等位基因谱，或者更重要的是， 解释了突变的DEAF1蛋白的显性负作用或可能的功能获得作用。我们将使用 CRISPR/Cas9介导的基因组工程以培育p.R227W和p.Q265P(与p.R226W和p.Q265P相似) P.Q264P在人类中)点突变敲入Dand的小鼠模型。神经行为测试将评估 突变的DEAF1蛋白对学习记忆的影响。我们还将确定转录水平的变化 出生后发育和成年海马体。一组常见的差异表达基因，很可能是 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 对Dand以及其他具有重叠临床表型的发育障碍的洞察。

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.