The SMA patient fibroblasts (GM03813, Coriell NIGMS human genetic cell repository) were obtained from a male patient diagnosed with type I SMA. The cells have a homozygous deletion of exons 7 and 8 in SMN1 and have two copies of the SMN2 gene. Healthy fibroblasts (GM23815, Coriell NIGMS human genetic cell repository) were used as a control. AON transfection was performed with Lipofectamine RNAiMAX (Invitrogen) in OptiMEM I serum-reduced media (Gibco) for 48 hours.