muscular atrophy. Type 1 SMA patients usually show symptoms at 6 months from birth, with a rapid disease progression that kills them by the age of two42. In an initial iPSC-based disease modeling study39, iPSCs were derived from fibroblasts of a type 1 SMA patient and differentiated into a disease-relevant cell type, motor neurons. Reduced survival of motor neurons differentiated from patient iPSCs was observed, compared to that of motor neurons derived from an unaffected control. Moreover, the SMA patient-derived iPSCs were able to respond to valproic acid and tobramycin, two compounds known to induce SMN protein levels, by increasing SMN protein levels and SMN protein-containing ‘gems’39. This study provides a proof-of-principle that patient-derived iPSCs could be used to model early-onset genetic diseases and serve as potential drug-screening platforms.
