Allele-Specific CRISPR Editing of Mutant HTT via SNP Targeting
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Solution Overview
Problem
Current therapies for Huntington's disease aim to reduce the expression of the mutant Huntingtin protein, but they often compromise the expression of the wild-type protein, potentially affecting normal neuronal function.
Innovation Solution
The use of a CRISPR-Cas9 platform for gene editing that selectively targets and reduces the expression of the mutant Huntingtin protein by editing single nucleotide polymorphisms (SNPs) without affecting the wild-type protein.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional therapies reduce mutant Huntingtin protein expression, then disease severity is reduced, but wild-type protein expression is compromised, affecting normal neuronal function
Solution Approach 1:
The patent applies local quality by designing allele-specific CRISPR-Cas9 guides that target only the mutant HTT allele containing the pathogenic CAG repeat expansion, while sparring the wild-type allele. The guide RNAs are specifically designed to recognize sequences unique to the mutant allele, enabling selective disruption of mutant protein production without affecting normal Huntingtin protein function.
Solution Approach 2:
The patent segments the HTT gene into distinct mutant and wild-type alleles based on the presence or absence of the pathogenic CAG repeat expansion. By targeting specific sequences within the mutant allele (such as the expanded CAG repeats or associated SNPs), the therapy selectively acts on only the harmful segment while preserving the functional wild-type segment.
2Object-affected harmful factors
If permanent disruption of HTT function is achieved, then mutant protein is eliminated, but adult neuronal function is compromised
Solution Approach 1:
The patent makes different parts of the HTT gene have different fates by applying CRISPR-Cas9 editing specifically to the mutant allele containing the CAG expansion, while leaving the wild-type allele intact. This localized editing approach ensures that only the harmful mutant protein production is disrupted, while normal neuronal functions dependent on wild-type HTT protein remain preserved.
Solution Approach 2:
The patent converts the harmful presence of the mutant allele into a beneficial selective target for editing. By designing guides that specifically recognize sequences within the mutant allele (such as the expanded CAG repeats or associated SNPs), the therapy turns the harmful genetic variant into the precise target for correction, thereby eliminating the harm while preserving normal function.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively reduces the expression of the disease-causing mutant Huntingtin protein while preserving the expression of the wild-type protein, thereby minimizing disruptions to normal neuronal function.
Implementation Method 1
The present invention is related to gene therapy. In particular, the gene therapy provides gene editing of single nucleotide polymorphisms (SNP) using a CRISPR-Cas9 platform.
Implementation Method 2
the gene therapy provides gene editing of single nucleotide polymorphisms (SNP) using a CRISPR-Cas9 platform. For example, an SNP can be edited from a Huntingtin (HTT) gene to treat Huntington's disease.
Implementation Method 3
the sgRNA molecule hybridizes to said first allele
Data Source
AI summary
The present invention contemplates-allele-specific gene editing based on targeting a heterozygous single nucleotide polymorphism (SNP) in a protein coding sequence associated with a genetic disease. The data shown herein demonstrates that the outcome of such gene editing creates a nonesense mutation that results in a marked and selective reduction of mutant protein without affecting wild type protein expression. Expression of a single CRISPR-Cas9 nuclease in neurons generated a high frequency of mutations in the targeted HD allele that included both small insertion/deletion mutations and viral vector insertions. Thus, as disclosed herein, allele-specific targeting of InDel and insertion mutations to heterozygous coding SNPs provides a feasible approach to inactivate autosomal dominant mutations that cause genetic disease.