Provided herein are RNAi molecules including a first strand containing a guide sequence and a second strand comprising a non-guide sequence where the non-guide sequence contains a bulge opposite the seed region of the guide sequences; e.g., opposite the cleavage sequence. In some aspects, the invention provides RNAi for treating Huntington's disease. Further provided herein are expression cassettes, vectors (e.g., rAAV, recombinant adenoviral, recombinant lentiviral, and recombinant HSV vectors), cells, viral particles, and pharmaceutical compositions containing the RNAi. Yet further provided herein are methods and kits related to the use of the RNAi, for example, to treat Huntington's disease.