Modulation of Exon Recognition in Pre-mRNA By Interfering with the Secondary RNA Structure

An isolated antisense oligonucleotide 16 to 50 nucleotides in length, wherein a part of said oligonucleotide is complementary to a strand of a double-stranded closed structure of the dystrophin exon 51 pre-mRNA and another part of said oligonucleotide is complementary to a single stranded open structure of the dystrophin exon 51 pre-mRNA, wherein said exon 51 pre-mRNA assumes a secondary structure within said exon comprising said open and closed structures, wherein said single stranded open structure is contiguous with said strand of said closed structure, wherein said oligonucleotide is capable of inducing exon 51 skipping, said oligonucleotide comprising a modification.