SMN1 and proximal spinal muscular atrophy: Zolgensma is a gene therapeutic leading to the production of SMN protein, but not under the control of the endogenous promoter, leading to incomplete restoration of SMN transcript levels in the spinal cord and expression in other tissues that could lead to toxicity.3 Thus, a pivotal therapeutic goal for SMA patients is to achieve permanent and endogenous regulation of rescued SMN levels.