Gapmer Antisense Oligonucleotides to Selectively Suppress the Mutant Allele in COL6A Genes in Dominant Ullrich Congenital Muscular Dystrophy.

Allele-specific gene silencing by antisense oligonucleotide (ASO) or small interference RNA (siRNA) has been used as a therapeutic approach for conditions caused by dominant gain-of-function mutations. We here present an antisense approach using gapmer ASO to diminish the dominant-negative effect in Ullrich congenital muscular dystrophy (UCMD) caused by dominant mutation in one of the COL6A genes. We provide the details of methods that our lab has used. The methods comprise the design of gapmer ASOs and the in vitro evaluation of gapmer ASOs on the specific silencing of the mutant allele at mRNA levels, and functional assessment at protein levels. A fibroblast cell line cultured from a UCMD patient carrying a dominant mutation in one of the COL6A genes is used as a cellular model.