The disclosure features compositions and methods for the treatment of disorders associated with improper ribonucleic acid (RNA) splicing, including disorders characterized by nuclear retention of RNAtranscripts containing aberrantly expanded repeat regions that bind and sequester splicing factor proteins. Disclosed herein are interfering RNA constructs that suppress the expression of RNA transcripts containing expanded repeat regions, as well as viral vectors, such as adeno-associated viral vectors, encoding such interfering RNA molecules. For example, the disclosure features interfering RNAmolecules, such as siRNA, miRNA, and shRNA constructs, that anneal to dystrophia myotonica protein kinase (DMPK) RNA transcripts and attenuate the expression of DMPK RNA containing expanded CUG trinucleotide repeats. Using the compositions and methods described herein, a patient having an RNA dominance disorder, such as a human patient having myotonic dystrophy, among other conditions described herein, may be administered an interfering RNA construct or vector containing the same so as to reduce the occurrence of spliceopathy in the patient, thereby treating an underlying etiology of the disease.