Antisense oligonucleotides capable of preventing or reducing exon 73 inclusion into the human COL7A mRNA are characterized in various ways: (a) the oligonucleotide's sequence includes at most two CpG sequences； (b) the oligonucleotide has a length of no more than 24 nucleotides； (c) the oligonucleotide is capable of annealing to the (SRp40/SC35 binding/ESE) element in exon73. These oligonucleotides can usefully be oligoribonucleotides with modified internucleosidic linkages e.g. phosphorothioate linkages.
