Selective Editing of the Mutant Huntingtin Gene

亨廷顿病的原因是三核苷酸CAG重复序列从36个以下增加 重复到36次或更多。重复次数的模式是42，大多数患者的重复次数在 40岁和45岁。这种疾病一般在30岁到40岁之间开始发病和发展。 认知、抑郁和异常运动。该基因是常染色体显性遗传。通过基因编辑，我们 目的消除亨廷顿病突变等位基因的表达或通过减少 CAG重复次数。我们将使用CRISPR-Cas9进行单核苷酸多态的选择性靶向 以防止突变的亨廷顿蛋白等位基因产生蛋白质。正在生成帧移位 SNP杂合性突变会减少突变的亨廷顿蛋白，但不会产生突变蛋白 碎片。在第二种方法中，我们减少了突变体中较高的CAG重复数 通过使用Cas9昵称，将等位基因转化为健康数量的CAG重复。昵称Cas9D10A用于 将CAG重复数降至致病阈值以下。我们有初步数据支持每一种 提案的一个方面。这一发现应用程序的目标是为有希望的治疗奠定基础 亨廷顿病和其他常染色体显性遗传性神经系统疾病的治疗 三核苷酸CAG重复扩增。

The cause of Huntington’s disease is an increase in the trinucleotide CAG repeat from under 36 repeats to 36 or greater repeats. The mode for the number of repeats is 42, and most patients have between 40 and 45. The disease generally starts between ages 30 and 40, with onset and progression of impaired cognition, depression, and aberrant movement. The genetics is autosomal dominant. With gene editing, we aim to eliminate expression of the mutant allele of Huntington’s disease or repair the mutation by reducing the number of CAG repeats. We will use CRISPR-Cas9 for selective targeting of single nucleotide polymorphisms with heterozygosities to prevent the mutant huntingtin allele from producing protein. Generating frameshift mutations at the SNP heterozygosity reduces mutant huntingtin protein, with no production of mutant protein fragments. In a second approach, we reduce the number of CAG repeats from a high number in the mutant allele to a healthy number of CAG repeats, through the use of Cas9 nickases. The nickase Cas9D10A is used to reduce the CAG repeat number below the pathogenic threshold. We have preliminary data that supports each aspect of the proposal. The goal of this discovery application is to set the stage for promising therapeutics for treatment of Huntington’s disease and other autosomal dominant neurological disorders caused by trinucleotide CAG repeat expansions.