Methods and compositions for treating trinucleotide repeat disorders

1. A method of repressing Htt expression in a cell, the method comprising providing a non-naturally occurring transcription factor that represses expression of an Htt gene, wherein the transcription factor comprises a repression domain and a zinc finger DNA-binding domain that binds to a target site of at least 9 nucleotides of the target sites as set forth in any of SEQ ID NO:20-23 and 36-39, wherein the zinc finger DNA-binding domain comprises a zinc finger protein that comprises 5 or 6 zinc finger recognition regions, ordered F1 to F5 or F1 to F6 from N-terminus to C-terminus, wherein the zinc finger protein comprises the recognition regions in the order shown in a single row of Table 1.

2. The method of claim 1 , wherein the Htt gene is wild-type.

3. The method of claim 2 , wherein the DNA-binding domain binds to a SNP associated with a wild-type allele.

4. The method of claim 1 , wherein the Htt gene comprises one or more expanded trinucleotide repeats.

5. The method of claim 4 , wherein the expanded trinucleotide repeat encodes poly-glutamine.

6. The method of claim 4 , wherein the expanded trinucleotide repeat encodes poly-serine.

7. The method of claim 4 , wherein the DNA-binding domain binds to a SNP associated with the expanded trinucleotide repeat.

8. The method of claim 1 , comprising providing a multimer comprising at least two zinc finger proteins that preferentially binds to expanded trinucleotide tracts as compared to wild-type trinucleotide repeat tracts.

9. The method of claim 1 , wherein the non-naturally occurring transcription factor is provided as a polynucleotide encoding the protein.

10. The method of claim 9 , wherein the polynucleotide is a viral or non-viral vector.

11. A method of treating Huntington's disease in a subject in need thereof, the method comprising repressing Htt expression in a cell of the subject according to the method of claim 1 .