This invention encompasses compounds, structures, compositions and methods for therapeutic guide molecules that direct CRISPR gene editing. A guide molecule for directing gene editing can be allele selective, or disease allele selective, and can exhibit reduced off target activity. A guide molecule can be composed of monomers, including UNA monomers, nucleic acid monomers, and modified nucleotides, wherein the compound is targeted to a genomic DNA. The guide molecules of this invention can be used as active ingredients for editing or disrupting a gene in vitro, ex vivo, or in vivo.
