Exondys51, a morpholino AON designed to restore the DMD reading frame by excluding exon 51, was recently granted accelerated approval in the USA and is relevant to 13% of DMD patients.15, 16, 17, 18, 19, 20, 21 In a small multi-year study, 12 boys who were amenable to reframing by skipping exon 51 were administered Exondys51 weekly by intravenous infusion.17 Here, DMD is linked to Duchenne muscular dystrophy.