Allele-Specific CRISPR Editing of Mutant HTT via SNP-Guided Cleavage

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Solution Overview

Problem

Current RNA interference methods do not completely eliminate mutant huntingtin protein levels in Huntington's disease, necessitating the development of more efficient genome editing systems like RNA-guided nucleases to target and modify specific genomic defects.

Innovation Solution

Utilizing CRISPR-Cas systems with RNA-guided nucleases that recognize and cleave mutant huntingtin (mutHTT) alleles through single nucleotide polymorphisms (SNPs) to introduce frameshift INDELs, reducing mutHTT mRNA and protein levels while sparing wild-type HTT expression.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If RNA interference is used to reduce mutant huntingtin protein levels, then mutant huntingtin expression is reduced, but complete elimination of mutant huntingtin is not achieved

Engineering Contradiction:

Improvemutant huntingtin protein levelsVSAvoidcomplete elimination of mutant huntingtin

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent replaces RNA interference (a post-transcriptional mechanism) with CRISPR-Cas9 genome editing (a direct genomic modification mechanism). This substitution enables permanent deletion of the mutant HTT allele at the DNA level, achieving complete elimination rather than just reduction of mutant huntingtin protein levels.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces the CRISPR-Cas9 system before the mutant huntingtin protein can cause significant damage, and uses it to preemptively delete the mutant allele from the genome. This preliminary genomic correction prevents the accumulation of mutant protein rather than merely reducing it after synthesis.

Inventive Principle:

Principle #10Preliminary action

2Measurement precision

If CRISPR-Cas9 systems are used to edit the mutant huntingtin allele, then specific genomic defects are targeted, but differentiation between mutant and wild-type alleles must be achieved

Engineering Contradiction:

Improvetargeting accuracy of mutant alleleVSAvoidallele-specific recognition system

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces a local distinguishing feature (a SNP-induced PAM motif) at a specific location in the mutant HTT allele. This local quality difference allows the CRISPR-Cas9 system to selectively target only the mutant allele while leaving the wild-type allele untouched, achieving allele-specific editing through a localized molecular marker.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses the PAM motif as an intermediary element that mediates between the CRISPR-Cas9 system and the mutant HTT allele. The PAM sequence serves as a recognition bridge that enables the guide RNA-Cas9 complex to specifically bind to and edit the mutant allele while ignoring the wild-type allele.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If genome editing systems are developed for therapeutic purposes, then treatment efficacy is improved, but time and experimentation are required to engineer effective nucleases

Engineering Contradiction:

Improvetherapeutic effectivenessVSAvoidtime to engineer effective nucleases

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent uses the naturally occurring CRISPR-Cas9 system from bacteria as a template or copy that can be adapted for human therapeutic use. Rather than engineering a completely new nuclease system, the invention leverages and modifies an existing, well-characterized system, significantly reducing development time while maintaining therapeutic effectiveness.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent exploits the universal nature of the CRISPR-Cas9 system, which can be programmed to target any DNA sequence by simply changing the guide RNA sequence. This multi-functionality allows the same Cas9 nuclease to be used against different mutant alleles without re-engineering, reducing the time required to develop effective therapeutic nucleases for various genetic conditions.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

Achieves at least 40% reduction in mutHTT mRNA and protein levels for at least 12 weeks, providing a therapeutic approach to ameliorate Huntington's disease symptoms by targeting the mutant allele specifically.

Implementation Method 1

The hybridization of the guide RNA to a particular target sequence allows editing at a specific location in a genome

Methodology Applied

Scientific EffectHybridization:

Implementation Method 2

compositions and methods for cleaving a mutant huntingtin (mutHTT) allele... RNA-guided nuclease (RGN) systems for cleaving a mutHTT allele

Methodology Applied

Scientific EffectNuclease cleavage:

Data Source

PatentUS20260069715A1Compositions and methods for the treatment of huntingtons disease by editing the mutant huntingtin gene

Publication Date: 2026.03.12 LIFEEDIT THERAPEUTICS INC

AI summary

Compositions include CRISPR RNAs, guide RNAs, and nucleic acid molecules encoding the same. Vectors and host cells comprising the nucleic acid molecules are also provided. Further provided are RNA-guided nuclease (RGN) systems for cleaving a mutHTT allele, wherein the RGN system comprises an RNA-guided nuclease and a guide RNA. The compositions find use in cleaving or modifying a mutHTT allele, and/or modifying the expression of a mutHTT allele. The compositions are additionally useful for treating Huntington's disease (HD), particularly in an allele-specific manner.