This effect has been previously reported in gene-edited cells of congenital muscular dystrophies patients bearing the p. Gly293Arg COL6A1 variant where the correction of the mutant allele by homologous-directed repair (HDR) occurred at a very low frequency (1%); however, the presence of frameshift variants and others resulting of NHEJ provoked the specific silencing of the mutant allele (40% of reads), with no effects on the wild-type allele. This evidence concerns the gene COL6A1 and muscular dystrophy.