The objective of this study is to evaluate the overall effectiveness and safety in patients with spinal muscular atrophy (SMA) treated with gene therapy Zolgensma® (onasemnogene abeparvovec) compared to Spinraza® (nusinersen). Non-interventional, non-randomized data collection using secondary data from the SMArtCARE registry. Based on SMA incidence information derived from the results of pilot new-born screening in Germany, the study is anticipated to enroll up to 599 pa-tients, which will be included both retrospectively and prospectively from the initiation of the SMArtCARE registry in July 2018 to the time of data cut for final analysis on December 31, 2026.