Inhibition of nonsense-mediated mRNA decay by antisense morpholino oligonucleotides restores functional expression of hERG nonsense and frameshift mutations in long-QT syndrome

► The expression of hERG nonsense and frameshift mutations is prevented by nonsense-mediated mRNA decay (NMD) in long QT syndrome. ► Inhibition of NMD by antisense morpholino oligonucleotides restores functional expression of hERG nonsense and frameshift mutations. ►Blocking downstream intron splicing is a potential strategy to prevent NMD and rescue some hERG nonsense and frameshift mutations.